[0001]The present invention relates to a surface-treated metal materiaL
Priority is claimed on Japanese Patent Application No. 2019-051864, filed
March 19, 2019, the content of which is incorporated herein by reference.
[Related Art]
[0002]
As techniques for forming a coating excellent in adhesion to the surface of a
metal material and imparting corrosion resistance, fingerprint resistance or the like to
the surface of a metal material, a method of applying chromate treatment to the surface
of a metal material with a treatment solution containing chromic acid, bichromic acid
or a salt thereof as a main component, a method of applying treatment using a
chromium-free metal surface treatment agent, a method of applying phosphate
treatment, a method of applying treatment with a silane coupling agent alone, a method
of applying organic resin coating treatment and the like are generally known and
practically used.
[0003]
As a technique mainly using an inorganic component, for example, Patent
Document 1 discloses a metal surface treatment agent containing a vanadium
compound and a metal compound containing at least one metal selected from the group
consisting of zirconium, titanium, molybdenum, tungsten, manganese and cerium.
[0004]
On the other hand, as a technique mainly using a silane coupling agent, for
- 1 -
example, Patent Document 2 discloses treatment for a metal sheet with an aqueous
solution containing a low concentration of an organic functional silane and a
crosslinking agent in order to obtain a temporary anticorrosive effect, and discloses a
method of forming a dense siloxane film by crosslinking the organic functional silane
with the crosslinking agent.
[0005]
Patent Document 3 discloses that a non-chromium surface-treated steel sheet
excellent in corrosion resistance, fingerprint resistance, blackening resistance, and
coating adhesion can be obtained by using a surface treatment agent containing a
specific resin compound (A), a cationic urethane resin (B) having at least one cationic
functional group selected from the group consisting of primary to tertiary amino
groups and a quaternary ammonium base, at least one silane coupling agent (C) having
a specific reactive functional group, and a specific acid compound (E), in which the
content of the cationic urethane resin (B) and the silane coupling agent (C) i s within a
predetermined range.
[0006]
As a technique for using a silane coupling agent as a main component, Patent
Document 4 discloses a technique in which a treatment solution having a specific pH is
prepared from a treatment agent containing a silane coupling agent I having a specific
functional group A and a silane coupling agent II having a heterologous functional
group B capable of reacting with the functional group A, the treatment solution is
applied to the surface of a metal material, and the treatment solution is heated and
dried to form a coating containing a reaction product of the silane coupling agent I and
the silane coupling agent II.
[0007]
- 2 -
Patent Document 5 discloses a technique using a surface treatment agent for a
metal material excellent in corrosion resistance containing, as components, (a) a
compound having two or more functional groups of a specific structure and (b) at least
one compound selected from the group consisting of an organic acid, a phosphoric acid,
and a complex fluoride, and having a molecular weight of 100 to 30000 per functional
group in the component (a).
[0008]
However, the techniques of Patent Documents 1 to 3 do not satisfy all of
corrosion resistance, heat resistance, fingerprint resistance, conductivity, coatability,
and black doposit resistance during processing, and still have problems in practical use.
Further, the techniques of Patent Documents 4 to 5 are techniques in which a silane
coupling agent is used as a main component, in which a plurality of silane coupling
agents are mixed and used. However, the hydrolyzability and the condensability of
the silane coupling agent, the reactivity of the organic functional group, and the effect
obtained thereby have not been sufficiently investigated, and a technique for
sufficiently controlling the properties of a plurality of silane coupling agents has not
been disclosed.
[0009]
Further, Patent Document 6 discloses a chromate-free surface-treated metal
material in which an aqueous metal surface treatment agent containing an
organosilicon compound (W) obtained by blending two silane coupling agents having
a specific structure at a specific mass ratio and a specific inhibitor is applied to the
surface of a metal material and dried to form a composite coating containing the
components.
[0010]
- 3 -
Further, Patent Document 7 discloses a metal material subjected to an
excellent chromate-free surface treatment excellent in each element of corrosion
resistance, heat resistance, fingerprint resistance, conductivity, coatability, and black
doposit resistance during processing, and a chromium-free metal surface treatment
agent used for imparting excellent corrosion resistance and alkali resistance to the
metal material.
[0011]
The techniques disclosed in Patent Document 6 and Patent Document 7 are
excellent techniques that have been put into practical use in a surface-treated steel
sheet subjected to a chromate-free surface treatment excellent in corrosion resistance,
heat resistance, fingerprint resistance, electrical conductivity, coatability, and black
doposit resistance during processing.
However, the plating layer containing aluminum, magnesium and zinc has a
plurality of phases. It has been found that when a coating is formed by performing
the surface treatment disclosed in Patent Document 6 and Patent Document 7 on a
metal material having such a plating layer on the surface thereof, there is a possibility
of a difference in corrosion resistance occurring depending on a location and a region
having low corrosion resistance being locally formed.
[Prior Art Document]
[Patent Document]
[0012]
[Patent Document 1] Japanese Unexamined Patent Application, First
Publication No. 2002-30460
[Patent Document 2] United States Patent No. 5,292,549
[Patent Document 3] Japanese Unexamined Patent Application, First
- 4 -
Publication No. 2003-105562
[Patent Document 4] Japanese Unexamined Patent Application, First
Publication No. 8-73775
[Patent Document 5] Japanese Unexamined Patent Application, First
Publication No. 2001-49453
[Patent Document 6] Japanese Unexamined Patent Application, First
Publication No. 2007-051365
[Patent Document 7] Japanese Patent No. 5336002
[Disclosure of the Invention]
[Problems to be Solved by the Invention]
[0013]
As described above, when a coating is formed by performing a conventional
surface treatment on a plating layer having a plurality of phases, there is a possibility
of a difference in corrosion resistance occurring depending on a location and a portion
having low corrosion resistance being locally formed. In order to ensure sufficient
corrosion resistance even in the region with the lowest corrosion resistance, the coating
may be made to contain more of an inhibitor than necessary. However, in a case
where more of the inhibitor than necessary is contained, performance such as coating
adhesion deteriorates.
[0014]
The present invention has been made in view of the above problems. An
object of the present invention is to provide a surface-treated metal material excellent
in corrosion resistance on the entire surface on which surface treatment has been
performed and also excellent in heat resistance, fingerprint resistance, conductivity,
coatability, and black doposit resistance during processing.
- 5 -
[Means for Solving the Problem]
[0015]
The present inventors have studied a method for preventing the formation of a
region having low corrosion resistance without increasing the inhibitor content from a
conventional leveL As a result, the present inventors have found that, in a surfacetreated
metal material having a coating such as a chemical conversion coating on a
plating layer, by unevenly distributing an inhibitor component contained in the coating
in the coating such that a large amount of the inhibitor component is present in a region
having low corrosion resistance, it is possible to suppress the local decrease in
corrosion resistance without increasing the content of the inhibitor from the
conventional leveL
[0016]
The present invention has been made based on the above findings, and the gist
thereof is as follows.
(1) A surface-treated metal material according to an aspect of the present
invention includes a metal sheet, a plating layer formed on the metal sheet and
containing aluminum, magnesium, and zinc, and a composite coating formed on a
surface of the plating layer, the composite coating including an organic silicon
compound, one or two of a zirconium compound and a titanium compound, a
phosphoric acid compound, a fluorine compound, and a vanadium compound, wherein,
when a surface of the composite coating is analyzed at a spot size of cp30 11m using
micro-fluorescent X-rays, a maximum value of V/Zn, which is a mass ratio of a V
content to a Zn content, is 0.010 to 0.100.
(2) In the surface-treated metal material according to (1 ), in the composite
coating, when analyzed with the micro-fluorescent X-rays at a spot size of cp30 11m, an
- 6 -
area ratio of a region in which the V/Zn is 0.010 to 0.100 to an entire measurement
range may be 1% to 50%.
(3) In the surface-treated metal material according to (1) or (2), in the
composite coating, when analyzed with the micro-fluorescent X-rays at a spot size of
<:p30 J.lm, a maximum value of V/Si, which is a ratio of a solid content mass of V to a
solid content mass of Si, may be 1.0 to 100.
(4) In the surface-treated metal material according to any one of (1) to (3), in
the composite coating, when analyzed with the micro-fluorescent X-rays at a spot size
of <:p2 mm, an average value of (Zr + Ti)/Si, which is a ratio of a total solid content
mass of one or two of Zr and Ti to a solid content mass of Si, may be 0.06 to 0.15, an
average value of P/Si, which is a ratio of a solid content mass of P to the solid content
mass of Si, may be 0.15 to 0.25, and an average value ofV/Si may be 0.01 to 0.10.
(5) In the surface-treated metal material according to any one of (1) to (4), a
chemical composition of the plating layer may contain Al: more than 4.0% to less than
25.0%, Mg: more than 1.0% to less than 12.5%, Sn: 0% to 20%, Bi: 0% to less than
5.0%, In: 0% to less than 2.0%, Ca: 0% to 3.0%, Y: 0% to 0.5%, La: 0% to less than
0.5%, Ce: 0% to less than 0.5%, Si: 0% to less than 2.5%, Cr: 0% to less than 0.25%,
Ti: 0% to less than 0.25%, Ni: 0% to less than 0.25%, Co: 0% to less than 0.25%, V:
0% to less than 0.25%, Nb: 0% to less than 0.25%, Cu: 0% to less than 0.25%, Mn: 0%
to less than 0.25%, Fe: 0% to 5.0%, Sr: 0% to less than 0.5%, Sb: 0% to less than 0.5%,
Pb: 0% to less than 0.5%, and B: 0% to less than 0.5%, with a remainder of Zn and
impurities.
[Effects of the Invention]
[0017]
An object of the present invention is to provide a surface-treated metal
- 7 -
material excellent in corrosion resistance on the entire surface on which surface
treatment has been performed and also excellent in heat resistance, fingerprint
resistance, conductivity, coatability, and black doposit resistance during processing.
[Brief Description of the Drawings]
[001 8]
FIG. 1 is a schematic cross section view of a surface~treated metal material
according to the present embodiment.
FIG. 2 is a diagram for explaining an assumed mechanism of concentration of
a vanadium compound.
[Embodiments ofthe Invention]
[0019]
Hereinafter, a surface-treated metal material according to an embodiment of
the present invention (a surface-treated metal material according to the present
embodiment) will be described.
As shown in FIG. 1, the surface-treated metal material! according to the
present embodiment includes a metal sheet 11, a plating layer 12 formed on the metal
sheet 11 and containing aluminum, magnesium, and zinc, and a composite coating 13
formed on a surface of the plating layer 12 and containing an organic silicon
compound, one or two of a zirconium compound and a titanium compound, a
phosphoric acid compound, a fluorine compound, and a vanadium compound.
In FIG. 1, the plating layer 12 and the composite coating 13 are formed on
only one side of the metal sheet 11, but they may be formed on both sides.
[0020]
Hereinafter, the metal sheet 11, the plating layer 12, and the composite
coating 13 will be described.
- 8 -
[0021]
The surface-treated metal material! according to the present embodiment has
excellent corrosion resistance, heat resistance, fingerprint resistance, conductivity,
coatability, and black doposit resistance during processing due to the plating layer 12
and the composite coating 13. Therefore, the metal sheet 11 is not particularly
limited. It may be determined depending on the product to be applied, the required
strength, the sheet thickness, and the like. For example, a hot rolled steel sheet
described in JIS G3193 :2008 or a cold rolled steel sheet described in JIS G3141 :2017
may be used.
[0022]
The plating layer 12 included in the surface-treated metal material I according
to the present embodiment is formed on the surface of the metal sheet 11 and contains
aluminum, magnesium, and zinc. Plating containing aluminum, magnesium, and zinc
has higher corrosion resistance than plating consisting of zinc or plating consisting of
zinc and aluminum. In the surface-treated metal material I according to the present
embodiment, the plating layer 12 contains aluminum, magnesium, and zinc in order to
obtain excellent corrosion resistance.
[0023]
The plating layer 12 preferably has a chemical composition of Al: more than
4.0% to less than 25.0%, Mg: more than 1.0% to less than 12.5%, Sn: 0% to 20%, Bi:
0% to less than 5.0%, In: 0% to less than 2.0%, Ca: 0% to 3.0%, Y: 0% to 0.5%, La:
0% to less than 0.5%, Ce: 0% to less than 0.5%, Si: 0% to less than 2.5%, Cr: 0% to
less than 0.25%, Ti: 0% to less than 0.25%, Ni: 0% to less than 0.25%, Co: 0% to less
- 9 -
than 0.25%, V: 0% to less than 0.25%, Nb: 0% to less than 0.25%, Cu: 0% to less than
0.25%, Mn: 0% to less than 0.25%, Fe: 0% to 5.0%, Sr: 0% to less than 0.5%, Sb: 0%
to less than 0.5%, Pb: 0% to less than 0.5%, and B: 0% to less than 0.5%, with the
remainder of Zn and impurities.
[0024]
The reason for the preferable chemical composition of the plating layer 12
will be described.
[Al: more than 4.0% to less than 25.0%]
Al is an element effective for ensuring corrosion resistance in a plating layer
containing aluminum (Al), zinc (Zn), and magnesium (Mg). In order to sufficiently
obtain the above effect, the Al content is preferably set to more than 4.0%.
On the other hand, when the Al content is 25.0% or more, the corrosion
resistance of the cut end face of the plating layer is decreased. Therefore, the Al
content is preferably less than 25.0%.
[0025]
[Mg: more than 1.0% to less than 12.5%]
Mg is an element having an effect of enhancing the corrosion resistance of the
plating layer. In order to sufficiently obtain the above effect, the Mg content is
preferably set to more than 1.0%.
On the other hand, when the Mg content is 12.5% or more, the effect of
improving the corrosion resistance is saturated and the workability of the plating layer
deteriorates. In addition, problems in manufacturing such as an increase in the
amount of dross generated in the plating bath occur. Therefore, the Mg content is
preferably set to less than 12.5%.
[0026]
- 10 -
The plating layer may contain AI and Mg, with the remainder being Zn and
impurities. However, the following elements may be further contained if necessary.
[0027]
[Sn: 0% to 20%]
[Bi: 0% to less than 5.0%]
[In: 0% to less than 2.0%]
When these elements are contained in the plating layer, a Mg2Sn phase
Mg3Bh phase, Mg3ln phase, and the like are formed as new intermetallic compound
phases in the plating layer.
These elements form an intermetallic compound phase only with Mg without
forming an intermetallic compound phase with any of Zn and Al constituting the
plating layer main body. When a new intermetallic compound phase is formed, the
weldability of the plating layer changes greatly. All of the intermetallic compound
phases have a high melting point and therefore exist as intermetallic compound phases
without evaporation after welding. Mg, which is originally likely to be oxidized by
welding heat to form MgO, is not oxidized because it forms intermetallic compound
phases with Sn, Bi, and In, and remains as intermetallic compound phases even after
welding, making it easier to remain as plating layer. Therefore, the presence of these
elements improves corrosion resistance and sacrificial protection corrosion resistance,
and improves corrosion resistance around the welded part. In order to obtain the
above effects, the content of each component is preferably set to 0.05% or more.
Among them, Sn is preferable because it is a low melting point metal and can
be easily contained without impairing the properties of the plating bath.
[0028]
[Ca: 0% to 3.0%]
- 11 -
When Ca is contained in the plating layer, the amount of dross that is likely to
be formed during the plating operation decreases as the Mg content increases, and the
plating operability improves. Therefore, Ca may be contained. In order to obtain
this effect, theCa content is preferably set to 0.1% or more.
On the other hand, when the Ca content is high, the corrosion resistance itself
of the flat surface portion of the plating layer tends to deteriorate, and the corrosion
resistance around the welded part may also deteriorate. Therefore, even when it is
contained, theCa content is preferably 3.0% or less.
[0029]
[Y: 0% to 0.5%]
[La: 0% to less than 0.5%]
[Ce: 0% to less than 0.5%]
Y, La, and Ce are elements that contribute to the improvement of corrosion
resistance. In order to obtain this effect, it is preferable to contain one or more
thereof each in an amount of 0.05% or more.
On the other hand, when the content of these elements is excessive, the
viscosity of the plating bath increases, the bath preparation itself often becomes
difficult, and a plated steel material having good plating properties cannot be
manufactured. Therefore, even when they are contained, it is preferable that the Y
content be set to 0.5% or less, the La content be set to less than 0.5%, and the Ce
content be set to less than 0.5%.
[0030]
[Si: 0% to less than 2.5%]
Si is an element that forms a compound together with Mg and contributes to
the improvement of corrosion resistance. In addition, Si is also an element having an
- 12 -
effect of suppressing an alloy layer formed between the surface of the metal sheet and
the plating layer from being formed excessively thick when the plating layer is formed
on the metal sheet, and enhancing the adhesion between the metal sheet and the plating
layer. In order to obtain this effect, the Si content is preferably set to 0.1% or more.
More preferably, it is 0.2% or more.
On the other hand, when the Si content is 2.5% or more, the excess Si is
precipitated in the plating layer, and not only does the corrosion resistance decrease but
the workability of the plating layer also decreases. Therefore, the Si content is
preferably set to less than 2.5%. More preferably, it is 1.5% or less.
[0031]
[Cr: 0% to less than 0.25%]
[Ti: 0% to less than 0.25%]
[Ni: 0% to less than 0.25%]
[Co: 0% to less than 0.25%]
[V: 0% to less than 0.25%]
[Nb: 0% to less than 0.25%]
[Cu: 0% to less than 0.25%]
[Mn: 0% to less than 0.25%]
These elements are elements that contribute to the improvement of corrosion
resistance. In order to obtain this effect, the content of each element is preferably set
to 0.05% or more.
On the other hand, when the content of these elements is excessive, the
viscosity of the plating bath increases, the bath preparation itself often becomes
difficult, and a plated metal material having good plating properties cannot be
manufactured. Therefore, the content of each element is preferably set to less than
- 13 -
0.25%.
[0032]
[Fe: 0% to 5.0%]
Fe is mixed into the plating layer as an impurity when the plating layer is
manufactured. The content may be up to about 5.0%, but within this range, the
adverse effect on the effect of the surface-treated metal material according to the
present embodiment is smalL Therefore, the Fe content is preferably set to 5.0% or
less.
[0033]
[Sr: 0% to less than 0.5%]
[Sb: 0% to less than 0.5%]
[Pb: 0% to less than 0.5%]
When Sr, Sb, and Pb are contained in the plating layer, the external
appearance of the plating layer is changed, spangles are formed, and improved metallic
luster is confirmed. In order to obtain this effect, the content of each of Sr, Sb, and
Pb is preferably set to 0.05% or more.
On the other hand, when the content of these elements is excessive, the
viscosity of the plating bath increases, the bath preparation itself often becomes
difficult, and a plated metal material having good plating properties cannot be
manufactured. Therefore, it is preferable that the Sr content be set to less than 0.5%,
the Sb content be set to less than 0.5%, and the Pb content be set to less than 0.5%.
[0034]
[B: 0% to less than 0.5%]
B is an element that, when contained in the plating layer, combines with Zn,
Al, and Mg to form various intermetallic compound phases. These intermetallic
- 14 -
compounds have the effect of improving LME. In order to obtain this effect, the B
content is preferably set to 0.05% or more.
On the other hand, when the B content becomes excessive, the melting point
of the plating rises remarkably, the plating operability deteriorates, and a plated metal
material having good plating properties cannot be obtained. Therefore, the B content
is preferably set to less than 0.5%.
[0035]
The amount of adhesion of the plating layer 12 is not limited, but it is
preferably 10 g/m2 or more in order to improve the corrosion resistance. On the other
hand, even when the amount of adhesion exceeds 200 g/m2
, the corrosion resistance is
saturated and it becomes economically disadvantageous. Therefore, the amount of
adhesion is preferably 200 g/m2 or less.
[0036]
The composite coating 13 provided on the surface of the plating layer 12 in
the surface-treated metal material! according to the present embodiment includes an
organic silicon compound, one or two of a zirconium compound and a titanium
compound, a phosphoric acid compound, a fluorine compound, and a vanadium
compound. When the composite coating contains an organic silicon compound, one
or two of a zirconium compound and a titanium compound, a phosphoric acid
compound, a fluorine compound, and a vanadium compound, corrosion resistance, heat
resistance, fingerprint resistance, conductivity, coatability, and black doposit resistance
during processing can be imparted to the surface-treated metal material 1.
[0037]
However, as described above, in the surface-treated metal material 1
- 15 -
according to the present embodiment, a plating layer containing aluminum, magnesium,
and zinc is used as the plating layer 12 in order to ensure corrosion resistance. Such a
plating layer containing aluminum, magnesium, and zinc has a plurality of phases.
When a coating such as a conventional chemical conversion treatment coating
is formed on a plating layer having a plurality of phases, there is a possibility of a
difference in corrosion resistance occurring depending on a location and a region
having low corrosion resistance being formed. When there is a region having low
corrosion resistance, corrosion occurs from that region, and thus, in the surface-treated
metal material 1, it is necessary to ensure sufficient corrosion resistance even in the
region having the lowest corrosion resistance.
In order to ensure sufficient corrosion resistance even in the region with the
lowest corrosion resistance, it is conceivable to increase the content of the inhibitor in
the coating, which contributes to the improvement of corrosion resistance. However,
in a case where more of the inhibitor than necessary is contained, other performance
such as coating adhesion deteriorates. Therefore, it is not preferable to simply
increase the content of the inhibitor in the coating.
[0038]
The present inventors have studied a method for improving the corrosion
resistance of the composite coating 13, particularly the corrosion resistance in a region
where the corrosion resistance is low, without increasing the content of the inhibitor in
the composite coating 13. As a result, they found that the corrosion resistance can be
improved without increasing the content of the inhibitor in the entire composite coating
13 by uniformly distributing components constituting the matrix such as an organic
silicon compound, a zirconium compound and/or a titanium compound, a phosphoric
acid compound and a fluorine compound and distributing a vanadium compound (V
- 16 -
compound) acting as an inhibitor to be present in a large amount in a region having
low corrosion resistance and present in an average amount in other regions in the
composite coating 13.
More specifically, they found that the vanadium compound may be distributed
such that the maximum value of V/Zn, which is the mass ratio between the V content
and the Zn content, is 0.010 to 0.100 when the surface of the composite coating 13 is
analyzed using micro-fluorescent X-rays.
Vanadium compounds are usually dispersed almost uniformly in the matrix of
the coating, but by making the treatment solution applied on the plating layer 12 acidic
and controlling the conditions from application to baking to the conditions described
below, the inhibitor components can be concentrated in the region having low
corrosion resistance during the process of applying the treatment solution and baking.
Although this mechanism is not clear, in a case where the treatment solution is acidic,
when the treatment solution is applied, the region having low corrosion resistance in
the plating layer 12 is selectively corroded and zinc is eluted. As the zinc is eluted,
the ambient pH rises. V ions are deposited in the portion where the pH rises and
becomes alkaline, and vanadium compounds such as V(OH)4 are precipitated. This
vanadium compound acts as an inhibitor. That is, it is assumed that Vis concentrated
in a region where the corrosion resistance was low, and the corrosion resistance of the
portion is improved. When the treatment solution is neutral or alkaline, the stability
of the treatment solution becomes poor.
[0039]
In the metal sheet of the present embodiment, when the maximum value of
V/Zn is 0.010 or more, it can be said that Vis sufficiently concentrated in the region
where the corrosion resistance was low. On the other hand, when the maximum value
- 17 -
of V /Zn exceeds 0.100, although V is concentrated in the region where the corrosion
resistance was initially low, the V content of portions other than the concentrated
portion is decreased due to excessive concentration of V, and the corrosion resistance
as a whole is decreased, which is not preferable.
[0040]
When the surface of the composite coating 13 is analyzed by microfluorescent
X-rays, information up to a certain depth can be obtained by the microfluorescent
X-rays, and thus Zn contained in the plating layer 12 is detected. Since it
is known that this Zn is dispersed substantially uniformly, it can be determined that V
is concentrated in the region where V/Zn is high.
[0041]
Conventionally, in order to prevent the elution of the inhibitor, there has been
a technique to uniformly adsorb a resin or the like in the vicinity of the surface of the
coating or in the vicinity of the interface between the coating and the plating layer.
However, in the metal sheet according to the present embodiment, Vis concentrated in
a region having low corrosion resistance to improve the corrosion resistance. The
fact that the corrosion resistance of the coating can be improved by such a method is a
finding newly found by the present inventors. In addition, in the surface-treated
metal material 1 according to the present embodiment, a sufficient V -concentrated
region can be formed by securing a time in which V is concentrated at a temperature
higher than a normal temperature during the formation of the composite coating 13.
Such concentration of V during coating formation has not been proposed in the past,
and is a method based on a new technical idea.
[0042]
In the composite coating 13, the area ratio of the region in which V/Zn is
- 18 -
0.010 to 0.100 (V-concentrated region) to the entire measurement range is preferably
1% to 50%. In this case, it is possible to improve the corrosion resistance by
concentrating V in the region where the corrosion resistance was initially low while
suppressing a decrease in the corrosion resistance in the region other than the Vconcentrated
region, which is preferable.
[0043]
Further, in the composite coating 13, the maximum value of V/Si, which is the
ratio of the solid content mass of V to the solid content mass of Si, is preferably 1.0 to
100. When the maximum value of V/Si is 1.0 to 100, the balance between the
concentration (precipitation) of V and the integrity of the coating becomes good.
Further, because the maximum value ofV/Si, which is the ratio of the solid
content mass of Si derived from the organic silicon compound and the solid content
mass of V derived from the vanadium compound contained in the matrix of the
composite coating 13, is independent of the presence or absence of Si in the plating
layer 12, the concentration of V can be known. In the composite coating 13 included
in the surface-treated metal material 1 according to the present embodiment, the
maximum value of V/Si of 1.0 to 100 is also an index indicating the presence of a Vconcentrated
region. It is assumed that the V concentration is caused by the selective
corrosion of a region having low corrosion resistance in the plating layer 12, the
elution of zinc, the rise of the ambient pH, and the precipitation of V ions as vanadium
compounds such as V(OH)4 in the portion which has become alkaline, thereby
imparting barrier properties and improving the corrosion resistance of the portion.
When the maximum value of V/Si is 1.0 to 100, it is considered that the vanadium
compound is precipitated in the region having low corrosion resistance.
[0044]
- 19 -
Further, in the composite coating 13, it is preferable that the average value of
(Zr + Ti)/Si, which is the ratio ofthe solid content mass ofZr derived from the
zirconium compound and/or the solid content mass of Ti derived from the titanium
compound to the solid content mass of Si derived from the organic silicon compound,
be 0.06 to 0.15, so that the homogeneity of the composite coating 13 is maintained.
When the average value of (Zr + Ti)/Si is less than 0.06, there is a concern that the
corrosion resistance may decrease due to insufficient barrier properties. Further,
when the average value of (Zr + Ti)/Si exceeds 0.15, the corrosion resistance is
saturated. The average value of (Zr + Ti)/Si is preferably 0.08 to 0.12.
Further, it is preferable that the average value of P/Si, which is the ratio of the
solid content mass of P derived from the phosphoric acid compound to the solid
content mass of Si derived from the organic silicon compound, be 0.15 to 0.25, so that
the homogeneity of the composite coating 13 is maintained. When the average value
of P/Si is less than 0.15, there is a concern that the corrosion resi stance will tend to
decrease due to the P shortage. Further, when the average value of P/Si exceeds 0.25,
there is a concern of the coating becoming water-soluble, which is not preferable.
The average value of P/Si is preferably 0.19 to 0.22.
Further, it is preferable that the average value of V/Si be 0.01 to 0.10 so that a
state in which the V compound is appropriately precipitated in the region having low
corrosion resistance is obtained while the homogeneity of the composite coating 13 is
maintained. When the average value ofV/Si is less than 0.01 , there is a concern of
the corrosion r esi stance decreasing due to the shortage of V, which is a corrosion
inhibitor. Further, when the average value of V/Si exceeds 0.10, there i s a concern of
the coating becoming water-soluble, which is not preferable. The average value of
V/Si is preferably 0.04 to 0.07.
- 20 -
[0045]
The maximum value of V rzn, the area ratio of V -concentrated region, the
maximum value of V/Si, the average value of (Zr + Ti)/Si, the average value of the
P/Si, and the average value of V/Si can be measured u sing micro-fluorescent X-rays.
Specifically, the maximum value of V/Zn, the area ratio of the V-concentrated
region, and the maximum value of V/Si are obtained by measuring the mass percent of
V, Zn, and Si in the detectable element constituting the composite coating 13, the
plating layer 12, and the metal sheet 11 with the number of pixels of 256 x 200 in a
region having a spot size of q> 30 ~m and a lateral direction of about 2.3 mm and a
longitudinal direction of about 1.5 mm with respect to the surface of the composite
coating by u sing micro-fluorescent X-rays (manufactured by AMETEK, Orbis energydispersive
X-ray fluorescence spectrometer, tube voltage: 5 kV, tube current: 1 rnA)
and Rh as an X-ray source, and calculating from the results.
Further, the average value of Zr/Si, the average value of P/Si, and the average
value of V/Si are obtained by measuring the mass percent of Zr, P, V, and Si in the
detectable element constituting the composite coating 13, the plating layer 12, and the
metal sheet 11 in the irradiation region (2 mmq>) in a region having a spot size of q> 2
mm with respect to the surface of the composite coating by using micro-fluorescent Xrays
(manufactured by AMETEK, Orbis energy-dispersive X-ray fluorescence
spectrometer, tube voltage: 5 kV, tube current: 1 rnA) and Rh as an X-ray source, and
calculating from the results.
[0046]
In the present embodiment, the organic silicon compound contained in the
composite coating 13 is not limited, but is obtained by blending, for example, a silane
coupling agent (A) containing one amino group in the molecule and a silane coupling
- 21 -
agent (B) containing one glycidyl group in the molecule at a solid content mass ratio
[(A)/(B)] of 0.5 to 1.7.
The blending ratio of the silane coupling agent (A) and the silane coupling
agent (B) is preferably 0.5 to 1.7 in terms of solid content mass ratio [(A)/(B)]. When
the solid content mass ratio [(A)/(B)] is less than 0.5, fingerprint resistance, bath
stability, and black doposit resistance may be significantly decreased. On the other
hand, when it exceeds 1.7, the water resistance may be significantly decreased, which
is not preferable. [(A)/(B)] is more preferably 0.7 to 1.7, and still more preferably 0.9
to 1.1.
[0047]
Examples of the silane coupling agent (A) containing one amino group
include, but are not particularly limited to, 3-aminopropyltriethoxysilane and 3-
aminopropyltrimethoxysilane, and examples of the silane coupling agent (B)
containing one glycidyl group in the molecule include 3-
glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.
[0048]
In the present embodiment, examples of the vanadium compound (V)
contained in the composite coating 13 include, but are not particularly limited to,
vanadium pentoxide V20s, metavanadate HV03, ammonium metavanadate, sodium
metavanadate, vanadium oxytrichloride VOCb, vanadium trioxide V203, vanadium
dioxide V02, vanadium oxysulfate VOS04, vanadium oxyacetyl acetonate
VO(OC( =CH2 )CH2COCH3 )2, vanadium acetylacetonate V (OC( =CH2)CH2COCH3 )3,
vanadium trichloride VCb, and phosphovanadomolybdic acid. Further, a pentavalent
vanadium compound reduced to a tetravalent or divalent vanadium compound by an
organic compound having at least one functional group selected from the group
- 22 -
consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to
tertiary amino group, an amide group, a phosphoric acid group, and a phosphonic acid
group can also be used.
[0049]
In the present embodiment, examples of the phosphoric acid compound
contained in the composite coating 13 include, but are not particularly limited to,
phosphoric acid, ammonium phosphate, potassium phosphate, and sodium phosphate.
Of these, phosphoric acid is more preferable. When phosphoric acid is used, better
corrosion resistance can be obtained.
[0050]
In the present embodiment, examples of the fluorine compound contained in
the composite coating 13 include, but are not particularly limited to, fluorides such as
hydrofluoric acid, fluoroboric acid, fluorosilicic acid, and water-soluble salts thereof,
and complex fluoride salts. Of these, hydrofluoric acid is more preferable. When
hydrofluoric acid is used, better corrosion resistance and coatability can be obtained.
[0051]
In the present embodiment, examples of the zirconium compound and/or the
titanium compound contained in the composite coating 13 include, but are not
particularly limited to, zirconium hydrofluoric acid, ammonium hexafluoride
zirconium, zirconium sulfate, zirconium oxychloride, zirconium nitrate, zirconium
acetate, ammonium hexafluorotitanate, and titanium hydrofluoric acid. Of these,
zircon hydrofluoric acid or titanium hydrofluoric acid is more preferable. When
zirconium hydrofluoric acid or titanium hydrofluoric acid is used, better corrosion
resistance and coatability can be obtained.
Further, zirconium hydrofluoric acid or titanium hydrofluoric acid is
- 23 -
preferable because it also acts as a fluorine compound.
[0052]
The amount of adhesion of the composite coating is preferably 0.05 to 2.0
g/m2
, more preferably 0.2 to 1.0 g/m2
, and most preferably 0.3 to 0.6 g/m2
. When the
amount of adhesion of the coating is less than 0.05 g/m2 , the surface of the metal
material cannot be coated and the corrosion resistance is significantly decreased, which
is not preferable. On the other hand, when it is larger than 2.0 g/m2, the black doposit
resistance during processing is decreased, which is not preferable.
[0053]
Next, a preferable manufacturing method of the surface-treated metal material
1 according to the present embodiment will be described. The effect of the surfacetreated
metal material 1 according to the present embodiment can be obtained
regardless of the manufacturing method as long as the surface-treated metal material 1
has the above-described characteristics. However, stable manufacture can be
achieved with a manufacturing method including the following steps.
[0054]
The surface-treated metal material according to the present embodiment is
obtained with a manufacturing method including a plating step of forming a plating
layer on the surface of a metal material by immersing the metal material such as a steel
sheet in a plating bath containing Zn, Al, and Mg, an applying step of applying the
surface treatment metal agent to the metal material having the plating layer, and a
composite coating forming step of forming a composite coating containing an organic
silicon compound, one or two of a zirconium compound and a titanium compound, a
phosphoric acid compound, a fluorine compound, and a vanadium compound by
heating (baking) the metal material to which the surface treatment metal agent is
- 24 -
applied.
[0055]
[Plating step]
The plating step is not particularly limited. A usual method may be used so
that sufficient plating adhesion is obtained.
Further, the method for manufacturing the metal material to be used in the
plating process is not limited.
[0056]
[Applying step]
In the applying step, a surface treatment metal agent containing an organic
silicon compound, one or two of a zirconium compound and a titanium compound, a
phosphoric acid compound, a fluorine compound, and a vanadium compound is
applied to the metal material having a plating layer.
The ratio (such as X/W, Y/W, and Z/W, where X/W means (Xl + X2)/W) of
one or two of a zirconium compound and a titanium compound (X2), a phosphoric acid
compound (Y), a fluorine compound (Xl), and a vanadium compound (Z) to an
organic silicon compound (W) is preferably adjusted in accordance with the ratio of
the target coating.
Further, in order to form the V -concentrated region, it is preferable to make
the surface treatment metal agent (treatment solution) to be applied acidic. By
making the treatment solution acidic, the region having low corrosion resistance in the
plating layer is selectively corroded and zinc i s eluted. The pH around the zinc-eluted
portion rises. In the portion where the pH rises and becomes alkaline, V ions are
deposited before the treatment solution dries, and vanadium compounds such as
V(OH)4 are precipitated. As a result, Vis concentrated in the region where the
- 25 -
corrosion resistance was low, and a V-concentrated region is formed.
The pH of the treatment solution can be adjusted by using organic acids such
as acetic acid and lactic acid, inorganic acids such as hydrofluoric acid, and pH
adjusters such as ammonium salts and amines.
When better corrosion resistance is required, it is preferable that the surface
treatment metal agent be applied within 10 to 60 seconds as elapsed time including
retaining the atmosphere at a humidity of 80% or more for 2 to 5 seconds, after plating
(after the plating is completed) and the temperature change of the plating layer is
controlled to be 300 octo 450 oc within this 10 to 60 seconds. Through this control,
the average value of V/Si, the average value of P/Si, and the average value of (Zr +
Ti)/Si fall within preferable ranges. In this case, the corrosion resistance is further
improved.
In order to control the average value of V/Si, the average value of P/Si, and
the average value of (Zr + Ti)/Si to be within the preferable ranges, at least two
preferred conditions among the time from plating to coating, the holding atmosphere
humidity, the retention time, and the temperature change of the plating layer need to be
satisfied. Further, in the case of a more preferable range, it is necessary to satisfy
three or more preferable conditions.
The reason why these conditions affect the improvement of corrosion
resistance is not clear, but a possible mechanism for, for example, the average value of
V/Si will be described with reference to FIG. 2.
As shown in FIG. 2(a), a case where a region r having low corrosion
resistance exists on the surface of the plating layer 12 after plating will be examined.
The surface of the plating layer 12 after plating is in an active state.
Therefore, as shown in FIG. 2(b), an oxide film 21 is formed on the surface of the
- 26 -
plating layer 12. In order to form the oxide film 21 with an appropriate thickness,
after plating, a treatment solution is applied to the surface of the plating layer 12 with
in the range from 10 to 60 seconds as elapsed time including retaining the plating layer
12 for 2 to 5 seconds in an atmosphere having a humidity of 80% or higher, and the
temperature of the plating layer 12 is changed to 300 octo 450 oc in this 10 to 60
seconds. Even when the oxide film 21 is formed in the low corrosion resistance
region r of the surface of the plating layer 12, the reaction between the V compound
and the surface of the plating layer 12 selectively proceeds in the low corrosion
resistance region due to application of the coating liquid. As a result, as shown in
FIG. 2(b ), the V compound 31 is concentrated in the region r having low corrosion
resistance. On the other hand, since the oxide film 21 is formed with an appropriate
thickness in the other region R of the surface of the plating layer 12, the reaction
between the V compound and the surface of the plating layer 12 is relatively smaller
than in the region r even when the treatment solution is applied. Therefore, the V
compound 31 is not concentrated in the "other region R". That is, in the "region r
having low corrosion resistance", the V -compound 31 is concentrated and the
corrosion resistance is improved, whereas in the "other region R", although the Vcompound
31 is not concentrated, a small amount of the V -compound 31 is present and
the oxide film 21 is formed with a sufficient thickness, so that the corrosion resistance
can be maintained.
On the other hand, when the treatment solution is applied to the surface of the
plating layer 12 within less than 10 seconds from the plating, the thickness of the oxide
film 21 on the surface of the plating layer 12 is not sufficient as shown in FIG. 2(c)
even when the treatment solution is previously retained for 2 to 5 seconds in an
atmosphere having a humidity of 80% or more and the temperature change is 300 oc to
- 27 -
450 °C. As described above, when the oxide film 21 is not formed with a sufficient
thickness, or when the oxide film 21 is not formed, the reactivity between the region r
having low corrosion resistance on the surface of the plating layer 12 and the other
region R is not greatly changed. Therefore, the V compound 31 is similarly
precipitated on the entire surface ofthe plating layer 12, and the V compound 31
cannot be selectively precipitated in the region r having low corrosion resistance.
Therefore, the improvement of the corrosion resistance of the region r having low
corrosion resistance due to the precipitation of the V compound 31 becomes
insufficient.
On the other hand, when the time from plating to application exceeds 60
seconds, as shown in FIG. 2(d), the oxide film 21 grows too thick even in the region r
on the surface of the plating layer 12 having low corrosion resistance. Therefore,
even when the treatment solution is applied after 60 seconds have passed from the
plating, a selective reaction with the treatment solution is unlikely to occur even in the
region ron the surface of the plating layer 12 having low corrosion resistance.
Therefore it is impossible to selectively precipitate V compounds 31 in a low region r
corrosion resistance, and due to the precipitation of V compounds 31, improvement in
corrosion resistance of low region r becomes insufficient.
Further, when the temperature change of the plating layer 12 within 10 to 60
seconds as elapsed time after plating, is less than 300 °C, the selective reaction
between the region r having low corrosion resistance on the surface of the plating layer
12 and the treatment solution is unlikely to occur. Therefore, the V compound 31 is
not sufficiently concentrated in the region r having low corrosion resistance. It is
presumed that this is because the difference in the reactivity to the treatment solution
between the region r having low corrosion resistance on the surface of the plating layer
- 28 -
12 and the other region R becomes small due to insufficient temperature change of the
plating layer 12.
On the other hand, when the temperature change is more than 450 °C, the
oxide film 21 may grow sufficiently and the reactivity with the coating liquid may not
be secured.
In addition, even when the plating layer 12 is not retained in an atmosphere
having a humidity of 80% or more for 2 seconds or more before the treatment solution
is applied, a selective reaction between a region r having low corrosion resistance on
the surface of the plating layer 12 and the treatment solution is hardly caused. It is
presumed that this is because the thickness of the oxide film 21 becomes insufficient
due to the insufficient growth time of the oxide film 21 in the atmosphere, and the
difference between the reactivity between the region r having low corrosion resistance
on the surface of the plating layer 12 and the treatment solution and the react ivity
between the other region R and the treatment solution becomes small. It is presumed
that when the retention time is more than 5 seconds, the oxide film 21 grows too thick
even in the region r having low corrosion resistance on the surface of the plating layer
12, and the difference between the reactivity between the region r having low corrosion
resistance on the surface of the plating layer 12 and the treatment solution and the
reactivity between the other region R and the treatment solution becomes small.
[0057]
In the applying step, the application method of the surface treatment metal
agent is not limited.
For example, the application can be performed using a roll coater, a bar coater,
a spray, or the like.
[0058]
- 29 -
[Composite coating forming step]
In the composite coating forming step, the metal material to which the surface
treatment metal agent is applied is heated to a peak metal temperature above 50 ac and
below 250 ac (highest peak metal temperature), dried, and baked. Regarding the
drying temperature, when the peak metal temperature is 50 ac or less, the solvent of
the aqueous metal surface treatment agent does not completely volatilize, which is not
preferable. On the other hand, when the temperature is 250 ac or more, a part of the
organic chain of the coating formed by the aqueous metal surface treatment agent is
decomposed, which is not preferable. The peak metal temperature is more preferably
60 acto 150 ac, and still more preferably 80 acto 150 ac.
Further, in the composite coating forming step, it is preferable to start heating
0.5 seconds or more after applying the surface treatment metal agent. By setting the
time from application to heating (coating film retention time) to 0.5 seconds or more, it
is possible to sufficiently secure a time until V ions are deposited and a vanadium
compound such as V(OH)4 is precipitated. When the time to heating is less than 0.5
seconds, the concentration of V becomes insufficient.
When applying a surface treatment metal agent to the plating layer 12 on a
roll coater, the temperature of the metal sheet 11 when the metal sheet 11 enters the
roll coater (hereinafter sometimes referred to as "metal sheet entry temperature") is
preferably 5 ac or more and 80 ac or less. When the metal sheet entry temperature
exceeds the above upper limit of 80 °C, depending on the composition of the surface
treatment metal agent, the evaporation of water in the aqueous surface treatment agent
may be too rapid, resulting in a phenomenon in which small bubble-like blisters or
holes are generated, a so-called Waki phenomenon. The metal sheet entry
temperature is more preferably 10 ac or more and 60 ac or less, and still more
- 30 -
preferably 15 oc or more and 40 oc or less.
The temperature of the surface treatment metal agent at the time of application
of the surface treatment metal agent onto the plating layer 12 is not particularly limited,
but may be, for example, 5 oc or more and 60 oc or less, preferably 10 oc or more and
50 oc or less, and more preferably 15 oc or more and 40 oc or less. By setting the
temperature of the aqueous surface treatment agent at the time of coating within the
above range, coating using a roll coater can be performed with excellent productivity,
and the composite coating 13 can be formed.
When the surface treatment metal agent is applied onto the plating layer 12,
Co treatment is preferably performed. The cobalt compound is present as an ion in
the treatment solution, and when the cobalt compound comes into contact with the
metal, the cobalt compound is substituted and precipitated on the metal surface. By
carrying out the Co treatment, it is possible to develop excellent blackening resistance
by modifying the metal surface with the cobalt compound.
[Examples]
[0059]
The metal sheets were immersed in a plating bath to obtain metal sheets M1 to
M7 having a plating layer shown in Table 1. In the description of Table 1, for
example, "Zn-0.5%Mg-0.2%Al" means that Mg is contained in an amount of 0.5% by
mass and Al is contained in an amount of0.2% by mass, with the remainder being Zn
and impurities.
The amount of adhesion of the plating layer was 90 g/m2
.
As the metal sheet, a cold-rolled steel sheet described in JIS G 3141:2017 was
used.
- 31 -
[0060]
A surface treatment metal agent containing an organic silicon compound, one
or two of a zirconium compound and a titanium compound, a phosphoric acid
compound, a fluorine compound, and a vanadium compound, as shown in Tables 2-1
to 2-10, and having an adjusted temperature was applied as a coating liquid to a metal
material having a plating layer ofM1 to M7 appropriately heated to a metal sheet entry
sheet temperature shown in Tables 2-1 to 2-10 using a roll coater without degreasing
after plating. When the surface treatment metal agent was applied onto the plating
layer, Co-treatment was performed for some examples.
Thereafter, the metal sheet was washed with water for 10 seconds using a
spray.
The viscosity of the surface treatment metal agent in each example at 25 oc
was in the range of 1 to 2 mPa· s.
Further, in the table, in the "silane coupling agent" of the organic silicon
compound, A1, A2, B1 and B2 indicate the following.
A1: 3-aminoprop yltrimethoxysilane
A2: 3-aminopropyltriethoxysilane
B 1: 3-glycidoxypropyltrimethoxysilane
B2: 3-glycidoxypropyltriethoxysilane
Further, in the V compound, Z1 and Z2 indicate the following.
Z1: vanadium oxysulfate VOS04,
Z2: vanadium oxyacetylacetonate VO(OC(=CH2)CH2COCH3)2.
[0061]
After applying the surface treatment metal agent and allowing the coating film
retention time in Tables 2-1 to 2-10 to elapse, the metal material to which the surface
- 32 -
treatment metal agent was applied was heated to the maximum reached sheet
temperatures of Tables 2- 1 to 2-10, dried, and baked. The coating film retention time
was adjusted by controlling the transfer speed of the steel sheet from the roll coater to
the heating furnace.
[0062]
With respect to the obtained composite coating, the maximum value of V/Zn,
the area ratio of the region in which V/Zn is 0.010 to 0.100 to the entire measurement
range, the maximum value of V/Si, the average value of (Zr + Ti)/S i, the average value
of P/Si, and the average value of V /Si were measured using micro-fluorescent X-rays.
Specifically, the maximum value of V/Zn, the area ratio of the V-concentrated
region, and the maximum value of V /Si were obtained by measuring the mass percent
of V, Zn, and Si in the detectable element constituting the composite coating, the
plating layer, and the metal sheet with the number of pixels of 256 x 200 in a region
having a spot size of ray test
Maximum
Area r atio of V
Maximum Average value
Average Average
concentrated value of value of N1 N2 N3
value of V/Zn
region
value of V /Si of (Zr+ Ti)/Si
P/Si V/Si
Inventive
0.015 6 4 5.7 0.11 0.20 0.09 4 4 4
Example99
Inventive
0.031 13 40.8 0.14 0.21 0.08 4 4 4
Example 100
Comparative
0.009 61 0.7 0.11 0.16 0.04 2 3 2
Example 26
Comparative
0.005 73 0.6 0.10 0.17 0.21 1 2 2
Example 1
Comparative
0.004 67 0.6 0.13 0.22 0.19 2 2 2
Example2
Comparative
0.005 68 0.9 0.15 0.20 0.25 2 3 2
Example 3
Comparative
0.008 59 0.3 0.09 0.25 0.18 3 3 2
Example4
Comparative
0.005 72 0.6 0.08 0.24 0.22 2 3 3
Example S
Comparative
0.004 64 0.5 0.12 0.19 0.17 3 2 2
Example6
Comparative
0.000 70 0.2 0.06 0.21 0.14 2 2 3
Example ?
Comparative
0.003 63 0.2 0.11 0.18 0.13 3 2 3
Example S
Comparative
0.008 76 0.2 0.07 0.23 0.16 2 3 2
Example9
Comparative
0.008 65 0.7 0.14 0.16 0.21 2 2 3
Example 10
Comparative
0.006 66 0.9 0.11 0.18 0.07 1 2 2
Example21
Comparative
0.009 71 0.5 0.07 0.25 0.03 2 2 1
Example22
Comparative
0.004 75 0.6 0.07 0.15 0.15 2 1 2
Example 11
Comparative
0.009 62 0.7 0.08 0.25 0.23 2 2 2
Example 12
Comparative
0.003 60 0.5 0.09 0.22 0.12 3 3 2
Example 13
Comparative
0.005 77 0.5 0.10 0.18 0.24 3 3 2
Example 14
Comparative
0.006 56 0.8 0.13 0.24 0.17 3 2 2
Example 15
Comparative
0.003 55 0.3 0.06 0.15 0.19 2 3 3
Example 16
Comparative
0.003 79 0.5 0.11 0.23 0.18 3 2 3
Example 17
Comparative
0.001 74 0.6 0.15 0.17 0.13 3 2 3
Example 18
Comparative
0.007 78 0.4 0.12 0.16 0.12 3 3 2
Example 19
Comparative
0.007 57 0.5 0.14 0.21 0.25 3 2 3
Example20
Comparative
0.003 80 0.3 0.09 0.20 0.04 2 1 2
Example23
Comparative
0.009 58 0.8 0.14 0.17 0.08 2 2 1
Example24
- 51 -
[0080]
As can be seen from Tables 1 to 3-5, in the inventive examples, the composite
coating was in a preferable state, and the corrosion resistance of the three arbitrarily
collected samples had a score of 3 or higher.
Further, although not shown in the tables, the inventive examples were also
excellent in heat resistance, fingerprint resistance, conductivity, coatability, and black
doposit resistance during processing.
On the other hand, in the comparative examples, the maximum value of V/Zn
was not within the range of the present invention, and the corrosion resistance was
decreased.
[0081]
A surface treatment metal agent was applied to the metal sheet M2 among the
metal sheets used in Example 1.
However, in Example 2, after plating, the plating was retained at the humidity
and the retention time shown in Tables 4-1 to 4-6, and the time from completion of
plating to coating was controlled as shown in Tables 4-1 to 4-6. The temperature
changes of the plating layer during the time from the completion of plating to the
coating are shown in Tables 4-1 to 4-6.
Regarding conditions other than those indicated above, a surface treatment
metal agent containing an organic silicon compound, one or two of a zirconium
compound and a titanium compound, a phosphoric acid compound, a fluorine
compound, and a vanadium compound, as shown in Tables 4-1 to 4-6, and having an
adjusted temperature was applied as a coating liquid to a metal material having a
plating layer ofM2 appropriately heated to a metal sheet entry sheet temperature
- 52 -
shown in Tables 4-1 to 4-6 using a roll coater without degreasing after plating. When
the surface treatment metal agent was applied onto the plating layer, Co-treatment was
performed for some examples.
Thereafter, the metal sheet was washed with water for 10 seconds using a
spray.
The viscosity of the surface treatment metal agent in each example at 25 oc
was in the range of 1 to 2 mPa· s.
Further, in the tables, in the "silane coupling agent" of the organic silicon
compound, A1, A2, B1 and B2 indicate the following.
A1: 3-aminopropyltrimethoxysilane
A2: 3-aminopropyltriethoxysilane
B 1: 3-glycidoxypropyltrimethoxysilane
B2: 3-gl ycidoxypropyltriethox ysilane
Further, in the V compound, Z1 and Z2 indicate the following.
Z1: vanadium oxysulfate VOS04,
Z2: vanadium oxyacetylacetonate VO(OC(=CH2)CH2COCH3)2.
[0082]
After applying the surface treatment metal agent and allowing the coating film
retention time in Tables 4-1 to 4-6 to elapse, the metal material to which the surface
treatment metal agent was applied was heated to the maximum reached sheet
temperatures of Tables 4-1 to 4-6, dried, and baked. The surface-treated metal
material was retained in the atmosphere described in Tables 4-1 to 4-6. The coating
film retention time was adjusted by controlling the transfer speed of the steel sheet
from the roll coater to the heating furnace.
- 53 -
[0083]
[Table 4-1]
Fluorine compound (XI ),
Organic silicon compound (W) zirconium compound or Phosphoric acid compound (Y) V compound (Z) Coating solution
Base titanium compound (X2)
material Silane coupling
Ratio Ratio Type Ratio Ratio Acidic/
a ent Molecular
Type Type neutral/
A B AlB
weight
XJW Phosphoric acid YIW ZIW alkaline
Inventive Example 5-l M-2 A2 Bl 1.0 3000 TiF61- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-2 M-2 A2 Bl 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-3 M-2 A2 Bl 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-4 M-2 A2 Bl 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-5 M-2 A2 Bl 1.0 3000 TiF61- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-6 M-2 A2 Bl 1.0 3000 ZrF62. 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-7 M-2 A2 Bl 1.0 3000 ZrF62. 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-8 M-2 A2 Bl 1.0 3000 TiF61- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-9 M-2 A2 Bl 1.0 3000 ZrF62
- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-10 M-2 A2 B l 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-11 M-2 A2 B l 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-12 M-2 A2 Bl 1.0 3000 ZrF62. 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-13 M-2 A2 Bl 1.0 3000 ZrF62. 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-14 M-2 A2 Bl 1.0 3000 ZrF62. 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-15 M-2 A2 Bl 1.0 3000 TiF61- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-16 M-2 A2 Bl 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-17 M-2 A2 Bl 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-18 M-2 A2 Bl 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
Inventive Example 5-19 M-2 A2 Bl 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Zl 0.075 Acidic
- 54 -
[0084]
[Table 4-2]
Fluorine compound (Xl),
Organic silicon compound (W) ziiconium compound or Phosph oric acid compound (Y) V compound (Z) Coating solution
titanium compound (X2)
Base material
Silane coupling
Ratio Ratio Type Ratio Ratio Acidid
a ent Molecular weight Type Type neutral/
A B AlB XJW Phosphoric acid Y/W Z/W alkaline
Inventive Example 5-20 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0 .20 Z1 0.075 Acidic
Inventive Example 5-21 M-2 A2 B1 1.0 3000 TiF62. 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 5-22 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 5-23 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 5-24 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 5-25 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 5-26 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 5-27 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 55-1 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 55-2 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 55-3 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 55-4 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 55-5 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 55-6 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 55-7 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 55-8 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 55-9 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
Inventive Example 55-10 M-2 A2 B1 1.0 3000 TiF62- 0.10 Phosphoric acid 0 .20 Zl 0.075 Acidic
Inventive Example 55-11 M-2 A2 B1 1.0 3000 ZrF62- 0.10 Phosphoric acid 0.20 Z1 0.075 Acidic
- 55 -
[0085]
[Table 4-3]
Fluorine compound (Xl),
Coating
Organic silicon compound (W) zirconium compound or Phosphoric acid compound (Y) V compound (Z)
solution
Base titanium compound (X2)
material Silane
Ratio Ratio Type Ratio Ratio Acidid
coupling agent Molecular weight T)pe Type neutral!
A B AlB XJW Phosphoric acid YIW ZIW alkaline
Inventive Example 55~12 M~2 A2 B1 l.O 3000 TiF/ · 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~13 M~2 A2 B1 l.O 3000 TiF62
. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~14 M~2 A2 B1 l.O 3000 TiF/ · 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 15 M~2 A2 B1 l.O 3000 TiF62
. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 16 M~ 2 A2 B1 l.O 3000 TiF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 17 M~2 A2 B1 l.O 3000 TiF/ · 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 18 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 19 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~20 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~21 M~2 A2 B1 l.O 3000 ZrF62• 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~22 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~23 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 24 M~ 2 A2 B1 l.O 3000 TiF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~25 M~2 A2 B1 l.O 3000 ZrF62• 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 26 M~ 2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~27 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~ 28 M~2 A2 B1 l.O 3000 TiF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~29 M~2 A2 B1 l.O 3000 TiF/ · 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~30 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
Inventive Example 55~31 M~2 A2 B1 l.O 3000 ZrF62. 0.10 Phosphoric acid 0.20 Z1 O.D75 Acidic
- 56 -
[0086]
[Table 4-4]
Temperature Metal sheet entry Surface
Time from Retention Coating film Maximum reached Composite coating
Retention change of plating temperature into treatment metal Co
plating to atmosphere retention time sheet temperature adhesion amount
time (sec) layer coater material treatment
coating (sec) humidity(%)
("C) ("C) temperature ("C)
(sec) ("C) (g/m2)
fuventive Example 5-1 29 81 4 343 30 30 2 100 No 0.3
fuventive Example 5-2 49 86 4 356 30 30 2 100 No 0.3
fuventive Example 5-3 65 83 3 295 30 30 2 100 No 0.3
fuventive Example 5-4 5 68 2 323 30 30 2 100 No 0.3
fuventive Example 5-5 20 82 3 303 30 30 2 100 No 0.3
fuventive Example 5-6 17 83 2 363 30 30 2 100 No 0.3
fuventive Example 5-7 10 92 7 386 30 30 2 100 No 0.3
fuventive Example 5-8 55 83 4 324 30 30 2 100 No 0.3
fuventive Example 5-9 2 52 5 353 30 30 2 100 No 0.3
fuventive Example 5-10 42 91 5 316 30 30 2 100 No 0.3
fuventive Example 5-11 60 81 5 323 30 30 2 100 No 0.3
fuventive Example 5-12 5 92 3 372 30 30 2 100 No 0.3
fuventive Example 5-13 38 88 10 396 30 30 2 100 No 0.3
fuventive Example 5-14 65 82 4 387 30 30 2 100 No 0.3
fuventive Example 5-15 50 88 2 334 30 30 2 100 No 0.3
fuventive Example 5-16 34 90 5 328 30 30 2 100 No 0.3
fuventive Example 5-17 34 80 4 313 30 30 2 100 No 0.3
fuventive Example 5-18 37 81 3 309 30 30 2 100 No 0.3
fuventive Example 5-19 85 94 5 463 30 30 2 100 No 0.3
- 57 -
[0087]
[Table 4-5]
Time from
Retention Temperatme Metal sheet entry Smface
Coating film Maximum Composite coating
plating to
atmosphere Retention change of plating temperatme into treatment metal
retention time reached sheet
Co
adhesion amount
coating (sec)
hmnidity time (sec) layer coater material
(sec) temperature ("C)
treatment
(g/ml)
(%) ("C) ("C) temperature ("C)
Inventive Example 5-20 29 92 4 377 30 30 2 100 No 0.3
Inventive Example 5-21 26 89 3 343 30 30 2 100 No 0.3
Inventive Example 5-22 43 80 3 354 30 30 2 100 No 0.3
Inventive Example 5-23 20 86 2 355 30 30 2 100 No 0.3
Inventive Example 5-24 16 82 2 354 30 30 2 100 No 0.3
Inventive Example 5-25 60 80 4 367 30 30 2 100 No 0.3
Inventive Example 5-26 60 82 2 324 30 30 2 100 No 0.3
Inventive Example 5-27 60 80 4 320 30 30 2 100 No 0.3
Inventive Example 55-1 11 85 4 343 30 30 2 100 No 0.3
Inventive Example 55-2 15 48 2 357 30 30 2 100 No 0.3
Inventive Example 55-3 53 80 3 300 30 30 2 100 No 0.3
Inventive Example 55-4 23 84 4 358 30 30 2 100 No 0.3
Inventive Example 55-5 72 92 3 326 30 30 2 100 No 0.3
Inventive Example 55-6 17 83 4 287 30 30 2 100 No 0.3
Inventive Example 55-7 52 84 3 363 30 30 2 100 No 0.3
Inventive Example 55-8 11 93 8 304 30 30 2 100 No 0.3
Inventive Example 55-9 32 85 2 335 30 30 2 100 Yes 0.3
Inventive Example 55-10 31 93 4 341 30 30 2 100 No 0.3
Inventive Example 55-11 31 90 3 355 30 30 2 100 No 0.3
- 58 -
[0088]
[Table 4-6]
Time from
Retention Temperature Metal sheet entry Surface
Coating film Maximum reached Composite coating
plating to
atmosphere Retention change of plating temperature into treatment metal
retention time sheet temperature
Co
adhesion amount
coating (sec)
humidity time (sec) layer coater material
(sec) ("C)
treatment
(g/m2)
(%) ("C) ("C) temperature ("C)
Inventive Example 55-12 17 80 3 315 30 30 2 100 No 0.3
Inventive Example 55-13 12 84 5 372 30 30 2 100 Yes 0.3
Inventive Example 55-14 10 87 4 300 30 30 2 100 No 0.3
Inventive Example 55-15 54 88 3 331 30 30 2 100 No 0.3
Inventive Example 55-16 19 80 4 379 30 30 2 100 No 0.3
Inventive Example 55-17 43 91 4 360 30 30 2 100 No 0.3
Inventive Example 55-18 48 82 3 306 30 30 2 100 No 0.3
Inventive Example 55-19 48 91 3 300 30 30 2 100 No 0.3
Inventive Example 55-20 7 80 1 315 30 30 2 100 Yes 0.3
Inventive Example 55-21 23 80 2 320 30 30 2 100 No 0.3
Inventive Example 55-22 17 86 2 393 30 30 2 100 No 0.3
Inventive Example 55-23 10 91 4 326 30 30 2 100 No 0.3
Inventive Example 55-24 20 87 7 391 30 30 2 100 No 0.3
Inventive Example 55-25 60 80 3 324 30 30 2 100 No 0.3
Inventive Example 55-26 32 93 3 369 30 30 2 100 No 0.3
Inventive Example 55-27 70 68 2 276 30 30 2 100 No 0.3
Inventive Example 55-28 60 84 4 363 30 30 2 100 No 0.3
Inventive Example 55-29 40 81 3 314 30 30 2 100 No 0.3
Inventive Example 55-30 52 93 3 300 30 30 2 100 No 0.3
Inventive Example 55-31 56 72 3 353 30 30 2 100 No 0.3
- 59 -
[0089]
With respect to the obtained composite coating, the maximum value ofV/Zn,
the area ratio of the region in which V/Zn is 0.010 to 0.100 to the entire measurement
range, the maximum value of V/Si, the average value of (Zr + Ti)/Si, the average value
of P/Si, and the average value of V/Si were measured using micro-fluorescent X-rays
in the same manner as in Example 1.
[0090]
[Corrosion resistance]
Further, the corrosion resistance of the obtained surface-treated metal material
was evaluated.
In order to evaluate the corrosion resistance, the salt spray test performed in
Example 1 and the combined cycle test (CCT) in accordance with JASO M-609-91
were performed.
In the combined cycle corrosion test (CCT), the white rust generation rate was
measured after 9 and 15 cycles of salt spray, in which (2 hours)~ drying (4 hours)~
wetting (2 hours) is set as one cycle using the manufactured plated steel sheet. The
white rust generation rate was determined by binarizing the corrosion evaluation
surface of the plating layer, determining a threshold value at which a non-corroded
portion and a white rust portion could be separated from each other, and measuring an
area ratio of a white portion using image processing software. The evaluation criteria
are as follows.
3: white rust generation area ratio is less than 5% of the total area
2: white rust generation area ratio is 5% or more and less than 20% of the total
- 60 -
area
1: white rust generation area ratio is 20% or more of the total area
Further, although not shown in the tables, all the examples of the salt spray
test were evaluated as 3 or more.
[0091]
The results are shown in Tables 5-1 to 5-3.
- 61 -
[0092]
[Table 5-1]
Corrosion resistance in Corrosion resistance in
Composite coating salt spray test salt spray test
(9 cvcles) (15 cvcles)
Maximum value Area ratio ofV Maximum Average value of Average value Average value
ofP/Si ofV/Si N1 N2 N3 N1 N2 N3
ofV/Zn concentrated region value ofV/Si (Zr+ Ti)/Si
Inventive Example 5-1 0.048 3 21.5 0 .11 0.19 0 .04 3 3 3 3 3 3
Inventive Example 5-2 0.025 31 12.0 0.10 0.22 0 .05 3 3 3 3 3 3
Inventive Example 5-3 0.016 2 44.7 0.07 0.23 0.09 3 3 3 2 2 3
Inventive Example 5-4 0.019 9 32.2 0.13 0.17 0 .02 3 3 3 2 2 3
Inventive Example 5-5 0.015 2 11.1 0.09 0.19 0.06 3 3 3 3 3 3
Inventive Example 5-6 0.013 6 34.2 0.12 0.20 0 .04 3 3 3 3 3 3
Inventive Example 5-7 0.026 40 24.4 0.11 0.20 0.06 3 3 3 3 3 3
Inventive Example 5-8 0.046 37 41.4 0.08 0.21 0 .05 3 3 3 3 3 3
Inventive Example 5-9 0.019 26 67.2 0.02 0.28 0.12 3 2 3 2 2 3
Inventive Example 5-10 0.022 37 54.3 0.09 0.21 0 .06 3 3 3 3 3 3
Inventive Example 5-11 0.046 31 32.7 0 .11 0.20 0 .05 3 3 3 3 3 3
Inventive Example 5-12 0.020 2 44.0 0.08 0.22 0 .06 3 3 3 3 3 3
Inventive Example 5-13 0.023 3 32.1 0.10 0.21 0 .06 3 3 3 3 3 3
Inventive Example 5-14 0.013 7 19.1 0.08 0.21 0.05 3 3 3 3 3 3
Inventive Example 5-15 0.061 49 28.8 0.10 0.21 0 .05 3 3 3 3 3 3
Inventive Example 5-16 0.082 34 53.8 0 .11 0.21 0.06 3 3 3 3 3 3
Inventive Example 5-17 0.029 11 35.1 0.10 0.19 0 .05 3 3 3 3 3 3
Inventive Example 5-18 0.016 5 20.7 0.08 0.21 0 .06 3 3 3 3 3 3
Inventive Example 5-19 0.085 34 78.1 0.14 0.16 0 .09 3 3 3 2 2 3
- 62 -
[0093]
[Table 5-2]
Corrosion resistance in Corrosion resistance in
Composite coating salt spray test salt spray test
(9 cycles) (15 cycles)
Maximum Area ratio of V Maximum value Average value of Average value Average value
value of V/Zn concentrated region of V/Si (Zr+Ti)/Si ofP/Si ofV/Si N1 N2 N3 N1 N2 N3
fuventive Example 5-20 0.015 10 11.5 0.09 0.19 0 .06 3 3 3 3 3 3
fuventive Example 5-21 0.018 4 33.3 0.09 0.19 0 .05 3 3 3 3 3 3
fuventive Example 5-22 0.026 5 29.6 0.10 0.21 0.07 3 3 3 3 3 3
fuventive Example 5-23 0.093 38 60.0 0.11 0.19 0.07 3 3 3 3 3 3
fuventive Example 5-24 0.080 16 83.6 0.11 0.21 0 .05 3 3 3 3 3 3
fuvent ive Example 5-25 0.017 14 8.4 0.11 0.21 0 .04 3 3 3 3 3 3
fuventive Example 5-26 0.018 7 31.3 0.10 0.22 0 .05 3 3 3 3 3 3
fuventive Example 5-27 0.013 14 34.6 0.10 0.20 0 .06 3 3 3 3 3 3
fuventive Example 55-1 0.025 16 74.3 0.11 0.20 0 .07 3 3 3 3 3 3
fuventive Example 55-2 0.055 2 18.4 0.12 0.21 0 .05 3 3 3 3 3 3
fuventive Example 55-3 0.014 7 2.4 0.11 0.20 0 .04 3 3 3 3 3 3
fuventive Example 55-4 0.072 37 87.6 0.10 0.21 0 .05 3 3 3 3 3 3
fuventive Example 55-5 0.024 21 56.1 0.10 0.19 0 .05 3 3 3 3 3 3
fuventive Example 55-6 0.093 48 48.4 0.12 0.19 0 .06 3 3 3 3 3 3
fuvent ive Example 55-7 0.092 16 5.9 0.11 0.20 0 .05 3 3 3 3 3 3
fuventive Example 55-8 0.018 6 37.3 0.09 0.21 0 .05 3 3 3 3 3 3
fuventive Example 55-9 0.027 8 1.2 0.09 0.19 0 .06 3 3 3 3 3 3
fuventive Example 55-10 0.036 23 30.0 0.08 0.19 0 .05 3 3 3 3 3 3
fuventive Example 55-11 0.012 5 9.3 0.09 0.19 0.04 3 3 3 3 3 3
- 63 -
[0094]
[Table 5-3]
Corrosion resistance in Corrosion resistance in
Composite coating salt spray test salt spray test
(9 cycles) (15 cycles)
Maximum value Area ratio ofV Maximum value Average value of Average value Average value
Nl N2 N3 Nl N2 N3
ofV/Zn concentrated region of V/Si (Zr+Ti)/Si of P/Si ofV/Si
Inventive Example 55-12 0.019 14 4 3.3 0.11 0.20 0.06 3 3 3 3 3 3
Inventive Example 55-13 0.019 10 28.2 0.11 0.21 0.06 3 3 3 3 3 3
Inventive Example 55-14 0.015 10 37.6 0.11 0.22 0.06 3 3 3 3 3 3
Inventive Example 55-15 0.027 37 45.4 0.09 0.21 0.07 3 3 3 3 3 3
Inventive Example 55-16 0.012 9 22.4 0.10 0.20 0.06 3 3 3 3 3 3
Inventive Example 55-17 0.076 21 10.4 0.10 0.19 0.06 3 3 3 3 3 3
Inventive Example 55-18 0.028 3 38.3 0.09 0.22 0.06 3 3 3 3 3 3
Inventive Example 55-19 0.023 8 25.1 0.09 0.20 0.05 3 3 3 3 3 3
Inventive Example 55-20 0.025 5 42.5 0.07 0.24 0.01 3 3 3 2 3 2
Inventive Example 55-21 0.012 5 4 5.5 0.09 0.22 0.04 3 3 3 3 3 3
Inventive Example 55-22 0.063 46 47.8 0.11 0.21 0.06 3 3 3 3 3 3
Inventive Example 55-23 0.027 9 8.6 0.12 0.19 0.04 3 3 3 3 3 3
Inventive Example 55-24 0.027 3 4 8.4 0.09 0.21 0.05 3 3 3 3 3 3
Inventive Example 55-25 0.0 16 14 22.9 0.10 0.22 0.06 3 3 3 3 3 3
Inventive Example 55-26 0.020 10 42.9 0.09 0.20 0.05 3 3 3 3 3 3
Inventive Example 55-27 0.026 14 32.6 0.17 0.12 0.15 3 2 3 2 2 3
Inventive Example 55-28 0.076 35 59.8 0.10 0.19 0.04 3 3 3 3 3 3
Inventive Example 55-29 0.011 5 22.5 0.09 0.20 0.05 3 3 3 3 3 3
Inventive Example 55-30 0.0 17 14 42.9 0.09 0.21 0.05 3 3 3 3 3 3
Inventive Example 55-31 0.092 23 96.6 0.08 0.20 0.06 3 3 3 3 3 3
- 64 -
[0095]
As can be seen from Tables 4-1 to 5-3, when the average value of (Zr + Ti)/Si,
the average value of P/Si, and the average value of V/Si were within the preferred
ranges, the corrosion resistance in the combined cycle test was also improved.
[Industrial Applicability]
[0096]
According to the present invention, a surface-treated metal material excellent
in corrosion resistance on the entire surface on which surface treatment has been
performed and also excellent in heat resistance, fingerprint resistance, conductivity,
coatability, and black doposit resistance during processing can be obtained.
Therefore, industrial applicability thereof is high.
[Brief Description of the Reference Symbols]
[0097]
11 metal sheet
12 plating layer
13 composite coating
21 oxide film
31 V compound
WE CLAIMS
1. A surface-treated metal material, comprising:
a metal sheet;
a plating layer formed on the metal sheet and containing aluminum,
magnesium, and zinc; and
a composite coating formed on a surface of the plating layer, the composite
coating including an organic silicon compound, one or two of a zirconium compound
and a titanium compound, a phosphoric acid compound, a fluorine compound, and a
vanadium compound,
wherein, when a surface of the composite coating is analyzed at a spot size of
