Art
[1]
The invention color relates to a surface modification process of the steel sheet and the steel sheet, more specifically, by forming a TiN modification layer over the stainless steel, a conventional annealing process comprising a titanium (Ti) to express a beautiful gold color to the surface of the steel strip gold color relates to a steel sheet and a manufacturing method that can.
BACKGROUND
[2]
Using color in modern society, increasing the desire that you want to create a variety of aesthetics in daily life, which is also true of steel, stainless steel, widely used in household goods, home and office supplies.
[3]
For this decorative coating painting, anodizing, electroplating (ECD), was several methods have been developed, the color-forming method for the stainless steel is chemical and physical vapor deposition (CVD and PVD) method such as a diffusion coating, thermal spraying, enamel coating is It is mainly used.
[4]
CVD method by thermal decomposition at the surface sent with the steam and the gas transport of the metal compound to a metal deposition method of the chemical vapor, the steel sheet which maintains the temperature in the room to precipitate the plated metal. PVD method, also known as dry plating, vaporizing a metal in a vacuum there is thereby deposited on the steel sheet can be classified as a vacuum vapor deposition method, sputtering method, ion plating method. PVD method can be coated in a refractory material such as titanium, and reacted by ionizing non-metal atoms in a vacuum it is possible to plate the coating compound, such as titanium nitride (TiN) is mainly used in color expression of the steel sheet.
[5]
This evaporation may have a problem that high cost is not possible and in the process occurs without special vacuum and sputtering apparatus. Furthermore, the delamination due to the low degree of adhesion of the modified layer deposited on the treated base material and the surface have also been pointed out as a problem.
[6]
(Patent Document 0001) Republic of Korea Laid-Open Patent Publication No. 10-2011-0104631 No. (2011.09.23. Public)
Detailed Description of the Invention
SUMMARY
[7]
The present invention is to provide a gold-colored steel sheet capable of expressing a color without exfoliation of the modified layer, and a method for manufacturing a gold-colored steel sheet capable of forming a color modifying layer via conventional annealing step without the need for costly special equipment It intends to provide.
Problem solving means
[8]
In the present gold colored steel sheet in accordance with one embodiment of the invention, the base material and the steel sheet comprises a modified layer formed on the surface reached the edge of the base material, wherein the modified layer is Ti: 10 wt%: 30 wt%, and N the TiN-modified layer comprising, satisfy the following is the alloy element content of the modified TiN layer (1).
[9]
(1) 0.1% ≤ C + Si + Al + Mn + Cr + Ni + Nb + Zr ≤ 35.0 wt%
[10]
Where, C, Si, Al, Mn, Cr, Ni, Nb, Zr refers to the content (% by weight) of the respective elements.
[11]
Further, according to one embodiment of the invention, the b * value of the L * a * b * color system of the TiN surface modification layer may be 25 or more.
[12]
Further, according to one embodiment of the invention, the base is N: may comprise 0.015% by weight: not more than 0.003 wt% and C + N.
[13]
Further, according to one embodiment of the invention, the thickness of the TiN layer modification may be at least 10nm.
[14]
Further, according to one embodiment of the invention, the thickness of the TiN layer is modified can be from 20 to 120nm.
[15]
Further, according to one embodiment of the invention, the steel sheet is a formal potential be greater than or equal to 300mV.
[16]
Production method of a gold colored steel sheet in accordance with one embodiment of the present invention, a steel sheet containing titanium (Ti), 0.3 to 1.5 wt% nitrogen (N 2 to form a TiN modification layer on the surface by the annealing heat treatment in) atmosphere, the satisfy the following alloying elements in the modified TiN layer (1).
[17]
(1) 0.1% ≤ C + Si + Al + Mn + Cr + Ni + Nb + Zr ≤ 35.0 wt%
[18]
Where, C, Si, Al, Mn, Cr, Ni, Nb, Zr refers to the content (% by weight) of the respective elements.
[19]
Further, according to one embodiment of the invention, the annealing heat treatment may be a continuous bright annealing treatment.
[20]
Further, according to one embodiment of the invention, the annealing heat treatment may be performed at 900 to 1,200 ℃ for 30 to 300 seconds.
[21]
Further, according to one embodiment of the invention, the steel sheet is N: may include less than 0.003% by weight.
[22]
Further, according to one embodiment of the invention, the steel sheet is C + N: may include 0.015% or less.
Effects of the Invention
[23]
Gold method of manufacturing a color steel sheet is economical to form a color modifying layer through the conventional annealing heat treatment without expensive special equipment, titanium is concentrated in the surface inside the material (Ti) and nitrogen (N) according to the invention it is possible to form a modified layer by diffusion reaction to produce the gold colored steel sheet without delamination.
[24]
Further, the steel sheet produced in accordance with the present invention has a b * value of the L * a * b * color system can represent more than 25 elegant gold color.
[25]
In addition, TiN modification layer of the steel sheet produced according to the present invention can have excellent corrosion resistance represented by the formula high potential.
Brief Description of the Drawings
[26]
1 is a schematic view showing the behavior of titanium and nitrogen in the normal steel.
[27]
Figure 2 is a schematic view showing the behavior of titanium and nitrogen of the present invention.
[28]
Figure 3 is a graph showing a corrosion resistance of TiN modification layer.
[29]
Figure 4 is a schematic view of the COLOR SPACE representing the L * a * b * color system.
[30]
Figure 5 is a picture taken of the surface modification layer a TiN outermost with FIB-TEM method.
[31]
Figure 6 is a graph showing the behavior of the alloying elements, the outermost surface layer.
Best Mode for Carrying Out the Invention
[32]
In the present gold colored steel sheet in accordance with one embodiment of the invention, the base material and the steel sheet comprises a modified layer formed on the surface reached the edge of the base material, wherein the modified layer is Ti: 10 wt%: 30 wt%, and N the TiN-modified layer comprising, satisfy the following is the alloy element content of the modified TiN layer (1).
[33]
(1) 0.1% ≤ C + Si + Al + Mn + Cr + Ni + Nb + Zr ≤ 35.0 wt%
[34]
Where, C, Si, Al, Mn, Cr, Ni, Nb, Zr refers to the content (% by weight) of the respective elements.
Mode for the Invention
[35]
Hereinafter will be described in detail with reference to the accompanying drawings, an embodiment of the present invention. The following examples will be presented to fully convey the scope of the invention to those of ordinary skill in the art. The present invention is not limited to the embodiments described herein may be embodied in different forms. Figures may be somewhat exaggerated to express the size of the components, for clarity, not shown, and a portion not related to the description in order to clarify the invention.
[36]
Method of producing gold color steel sheet according to the present invention is not a titanium (Ti) is applied by a conventional physical or chemical vapor deposition, the titanium contained in the steel composition are concentrated onto the surface from the inside is characterized in forming a TiN modification layer .
[37]
Production method of a gold colored steel sheet in accordance with one embodiment of the present invention is a steel sheet containing titanium (Ti), 0.3 to 1.5 wt% nitrogen (N 2 can be formed in the TiN modification layer on the surface by the annealing heat treatment in) atmosphere.
[38]
In the present invention, by thickening the titanium (Ti) contained in the steel through an annealing heat treatment in the surface layer is treated nitride (Nitriding). Sufficiently concentrated in the surface layer is titanium, and in combination with the activated nitrogen (N) is diffused in the steel to form a TiN layer modified nitride layer, whereby it is possible to express a beautiful gold color on the steel surface.
[39]
Method of producing gold color steel sheet according to one embodiment of the invention, steel can be composition of the titanium so that the concentration of the surface layer during annealing heat treatment by smooth so that it contains 0.3 to 1.5% by weight of the (Ti). If the case where the content of titanium (Ti) is less than 0.3 wt% does not have a thickening of the smooth surface is difficult modified TiN layer is formed, exceeds 1.5% by weight of the first stiffness is reduced.
[40]
1 is a schematic view showing the behavior of titanium and nitrogen in the normal steel. In general, titanium (Ti) is deposited on the TiC or TiN as a base in combination with the carbon or nitrogen exhibits a high reactivity with the carbon (C) and nitrogen (N) contained in the steel, the annealing heat treatment. Titanium has a high carbide forming ability than the chromium (Cr) is thereby prevent chromium deficiency by forming TiC, and improve the wear resistance by forming a TiN. However, this way carbon and nitrogen contained in the steel, so the problem of precipitation in the concentrated upon TiC or TiN of titanium, it is necessary to control the content of carbon and nitrogen.
[41]
Therefore, it is possible to include a method of producing gold color steel sheet is 0.3 or less and 0.003 wt.% Nitrogen with titanium (Ti) of 1.5% by weight (N) in accordance with one embodiment of the present invention. If it included in the content of nitrogen (N) more than 0.003% by weight, since the TiN is precipitated during annealing heat treatment reduced the amount of titanium is concentrated in the surface layer may be difficult TiN modification layer formation.
[42]
In addition, the production method of a gold colored steel sheet in accordance with one embodiment of the present invention (hereinafter referred to, C + N.) Of the steel composition of the steel sheet the sum of the carbon (C) and nitrogen (N) content is 0.015 wt% or less can. When the content of C + N exceeds 0.015% by weight, since the annealing heat treatment reduced the amount of titanium (Ti) to be concentrated in the surface layer becomes easy to precipitation of TiC and TiN, C + N content of the steel sheet are concentrated in titanium so as to facilitate it is preferably not more than 0.015% by weight.
[43]
Figure 2 is a schematic view showing the behavior of titanium and nitrogen of the present invention. 2, the steel is being heated above the recrystallization temperature through the annealing heat treatment are able to move by diffusion of titanium (Ti). Titanium can form a modified TiN layer in combination in the surface layer and active nitrogen (N) from diffusing into the strong affinity with the nitrogen steel. Activated nitrogen is by binding to continuously since the affinity is strong thickening titanium also continuously activated surface diffusion of nitrogen into the steel-modified TiN layer may be formed in a sufficient thickness.
[44]
Annealing heat treatment is a nitrogen (N 2 may be made from) atmosphere. Since the titanium (Ti) to be concentrated in the surface layer is essential to the penetration of nitrogen atoms (N) to form a modified TiN layer, it is possible to annealing heat treatment in a nitrogen atmosphere.
[45]
In addition, the annealing heat treatment may be a continuous bright annealing treatment (Bright Annealing Line, BAL). Bright annealing is the annealing is performed in an oxygen-free atmosphere, because the high temperature oxide is formed compared to the annealing pickling is performed in an oxygen atmosphere can be inherent in the gloss retention and the like are generally used building interior materials, home appliances that require a beautiful surface. Nitrogen (N 2 by carrying out a bright annealing in) atmosphere TiO 2 can be suppressed to maximize the fraction of the fraction of TiN.
[46]
The annealing heat treatment is a nitrogen (N 2 may be performed for 30 to 300 seconds at a temperature range of from 900 to 1,200 ℃ (Furnace) in the) atmosphere.
[47]
If the annealing heat treatment temperature is lower than 900 ℃ nitrogen molecule (N 2 if it is difficult to decompose to active nitrogen (N) which can react with) the titanium thickening the steel surface (Ti), it exceeded 1,200 ℃ grain size (Grain Size ) may be coarse. Therefore, the heat treatment is annealing temperature range is more preferred and a 900 to 1,200 ℃ suitably, 950 to 1,150 ℃.
[48]
Further, if the annealing heat treatment time shorter than 30 seconds is difficult to obtain a sufficient thickness of the TiN layer modification, if it exceeds 300 seconds, may receive the grain size (Grain Size) The moldability decreases, such as coarse becomes bent. Therefore suitably the box annealing heat treatment for 30 to 300 seconds, and still more preferably 30 to 100 seconds.
[49]
The nitrogen (N 2 ) active nitrogen (N) in the surface layer of the steel sheet through an annealing heat treatment in the atmosphere can penetrate and spread.
[50]
On the other hand, to facilitate diffusion of the steel of the activated nitrogen (N), there are alloying elements designed to control the low amount of trace elements to prevent the penetration and diffusion of the active nitrogen (N) it can be associated. Penetration and diffusion of active nitrogen (N) is easily the higher the nitrogen affinity of the alloy elements that are employed in steel. Therefore, elements such as nitrogen affinity is relatively low carbon (C), boron (B), silicon (Si), cobalt (Co), copper (Cu), tungsten (W), molybdenum (Mo), manganese (Mn) it is a low content of glass.
[51]
TiN modification layer can be formed by the penetration and diffusion of the active nitrogen (N) generated by the high temperature thickening and a titanium (Ti) of the steel due to the annealing heat treatment. The titanium concentrated in the surface layer can form a TiN reacted with activated nitrogen, by controlling the annealing heating temperature and time to control its thickness. To display a gold color on the steel surface is preferably formed to a thickness at least 10nm or more. Improved hardness with a gold color for a stable expression, such as TiN modification layer formation is more preferably formed with a thickness of 20 to 120nm.
[52]
Production method of a gold colored steel sheet in accordance with one embodiment of the present invention, to form a TiN layer on the steel surface modification can be expressed to gold color. TiN modification layer formed on the steel surface by the annealing heat treatment indicates the nature of gold color. In order to express a beautiful gold color to the steel surface and the amount of titanium in the TiN modification layer (Ti) and nitrogen (N) should be above a certain level, the amount of titanium is at least 30% by weight or more, the content of nitrogen is at least 10% by weight or more is preferable. Further, the sum of the alloy element content than the TiN layer within the modified titanium (Ti) and nitrogen (N) may satisfy the following formula (1).
[53]
(1) 0.1% ≤ C + Si + Al + Mn + Cr + Ni + Nb + Zr ≤ 35.0 wt%
[54]
The lower limit of the expression (1) is in accordance with the general low alloy carbon steel or IF (Interstitial Free) Steel alloy components. Typical low alloy carbon steel, because the carbon (C) and which contains nitrogen (N), IF steel also titanium in order to remove the carbon and nitrogen (Ti), niobium (Nb), aluminum (Al) or the like is used TiN modified This is because a very small amount of alloy elements can be included within a layer. In contrast, the upper limit of the expression (1) is a stainless steel containing a large amount of alloying elements such as chromium (Cr), nickel (Ni) may be appropriate. When the sum of the alloy element content of TiN modification layer exceeds 35.0% by weight of the content of titanium (Ti) and nitrogen (N) it may be difficult to lower expression of a gold color.
[55]
TiN modification layer may represent a nitride film characteristics high hardness, a formula potential be greater than or equal to 300mV. Formula is stainless steel, one aluminum the surface of the passivated metal or alloy such as a titanium alloy or a corrosion is generated holes and puddles, formal potential represents the resistance value for the formulation of the surface.
[56]
Figure 3 is a graph showing a corrosion resistance of TiN modification layer. 3, the steel sheet produced by the production method of a gold colored steel sheet in accordance with one embodiment of the present invention is due to the TiN modification layer sulfuric acid corrosion resistance and salt corrosion resistance may have a formal potential of STS than 304 grades excellent . That is, TiN modification layer of the steel surface can provide excellent corrosion resistance to the steel sheet.
[57]
The steel sheet produced by the production method of a gold colored steel sheet in accordance with one embodiment of the present invention to provide a b * value of the L * a * b * color system can represent more than 25. * A * b * color system is L as the color coordinate system used in the most popular in the current field in all to describe the color of an object, L * represents a lightness, a *, b * represents a hue and saturation, respectively.
[58]
Figure 4 shows a schematic view of the COLOR SPACE representing the L * a * b * color system. Referring to Figure 4, + a * is red (Red) direction, -a * is green (Green) direction, + b * is yellow (Yellow) direction, and -b * represents blue (Blue) direction, the value is the higher indicates a bright color. In order to have a beautiful gold color and the b * value means yellow higher, TiN content of the modified layer of titanium (Ti) and nitrogen (N) is greater than each of at least 30% by weight and 10% by weight, as described above To this end, have. b * values ​​of the L * a * b * color system to indicate a more elegant gold color is preferably not less than 27.
[59]
[60]
The present invention through the following embodiments to be described in more detail.
[61]
Example
[62]
Titanium (Ti) contained 1.3% by weight and treated 60 seconds continuous bright annealing of cold rolled steel plate of 3mm to 1100 ℃ in (Furnace) in a nitrogen atmosphere. The chromaticity of the steel surface after the annealing process is completed was measured using a ColorQuest XE (Hunter Lab / USA) equipment. In addition, after processing the surface of the steel sheet # 600 grinding using 3.5% NaCl solution at room temperature to measure the potential of formula are shown in Table 1 below.
[63]
TABLE 1
division L * a * b * color system b * value TiN modification layer thickness (nm) Official potential (mV)
Example 1 28.71 65 400
Example 2 28.10 65 410
Example 3 29.24 65 420
Example 4 34.42 75 700
Example 5 33.88 70 600
Example 6 34.66 75 700
Comparative Example 1.77 0 40

[64]
Referring to Table 1, subjected to bright annealing heat treatment for 60 seconds at the annealing temperature of 1,100 ℃ was obtained a modified TiN layer of 65 to 75nm thickness. Embodiment shown in the Example 4, the steel sheet in Figure 5, taken with the FIB-TEM method. It was found that this modified TiN layer of about 75nm is formed.
[65]
Figure 6 Example 1 is a graph analysis of the behavior of the alloying elements according to the depth from the surface of the steel sheet, even a content of titanium and nitrogen to about 60nm from the surface by more than 10% by weight to 30% by weight, respectively when referring to the 6 , to the sum of the contents of the other alloying elements are available for the range of 0.1 to 35.0% by weight of the composition of TiN was satisfied modification layer that is an object of the present invention.
[66]
If the comparison not subjected to bright annealing continuous process according to the present invention example was not a b * value that indicates the yellow (Yellow) express all the gold color to 1.77, the embodiment 1 for a to 6 both b * value is 28 or higher represented were able to express a beautiful gold color.
[67]
In Examples 1 to 6 are all official potential was found that exhibits a more than 400mV excellent in corrosion resistance.
[68]
In the above-described bar, although the description has been made to exemplary embodiments of the present invention, in the present invention is not limited to those skilled in the art without departing from the spirit and scope of the claims set forth in the following it will be appreciated from the various changes and modifications are possible.
Industrial Applicability
[69]
Gold colored steel sheet in accordance with embodiments of the present invention is applicable for the purpose, such as an external property is emphasized interior pipe, building interior and exterior materials or exterior materials of home appliances.

Claims
[Claim 1]
In the base metal and the steel sheet comprises a modified layer formed on the surface reached the edge of the base material, wherein the modified layer is Ti: 30 wt% and N: and TiN-modified layer comprising at least 10% by weight, wherein the TiN-modified layer in the alloy gold color satisfying the following the element content of the formula (1) steel sheet: (1) 0.1% ≤ C + Si + Al + Mn + Cr + Ni + Nb + Zr ≤ 35.0% wherein, C by weight, Si, Al, Mn , Cr, Ni, Nb, Zr refers to the content (% by weight) of the respective elements.
[Claim 2]
The method of claim 1, wherein the modification layer TiN * a * b * color system of L * value is 25 or more b gold colored steel sheet of the surface.
[Claim 3]
The method of claim 1, wherein the base material is N: 0.003% or less, and C + N: 0.015% by weight gold colored steel sheet comprising a.
[Claim 4]
The method of claim 1, wherein the thickness of the TiN layer is 10nm or more modified gold colored steel sheet.
[Claim 5]
The method of claim 4, wherein the gold-colored steel sheet thickness of the TiN layer is modified from 20 to 120nm.
[Claim 6]
The method of claim 1, wherein the steel sheet has a gold colored steel sheet or more formal potential is 300mV.
[Claim 7]
A steel sheet containing titanium (Ti), 0.3 to 1.5 wt% nitrogen (N 2 ), and the annealing heat treatment in the atmosphere to form a TiN modification layer on the surface, gold satisfying the following are the alloy elements the TiN modification layer formula (1) of the color steel sheet produced by: (1) 0.1% ≤ C + Si + Al + Mn + Cr + Ni + Nb + Zr ≤ 35.0% by weight, where, C, Si, Al, Mn , Cr, Ni, Nb, Zr are It means the content (% by weight) of the respective elements.
[Claim 8]
The method of claim 7, wherein the annealing heat treatment method for producing a gold-colored bright annealing steel continuous processing.
[Claim 9]
Claim 7 or claim 8 wherein the process for producing a gold-colored steel sheet to the annealing heat treatment is performed for 30 to 300 seconds at 900 to 1,200 ℃.
[Claim 10]
The method of claim 7, wherein the steel sheet is N: method for producing a gold-colored steel sheet containing less than 0.003% by weight.
[Claim 11]
11. The method of claim 10, wherein the steel sheet is C + N: method for producing a gold-colored steel sheet containing 0.015% by weight or less.