[1]The present invention relates to corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet and a method of manufacturing the same.
[2]
BACKGROUND
[3]Zn-Ni coated steel sheet exhibits excellent corrosion resistance compared to pure zinc-plated steel sheet by introduction of the stable element, nickel electrochemically. However, conventional electroplated Zn-Ni plated steel sheet prepared by the process is greater than the residual stress due to the low process temperature, zinc, nickel base material (Parents metals). Further, when increase in the nickel content of the plating layer to improve corrosion resistance, residual stress and increasing by generating a plating layer cracking, becomes workability to heat by the coating layer hardness increases, it decreases the possession of iron and Zn-Ni plated layers potential victim way the castle is to be opened.
[4]
[5]
To improve the Zn-Ni plating corrosion resistance and workability (or corrosion resistance after processing) of the plate there is a variety of studies have been conducted, one of which it is a Patent Document 1 By configuring the Patent Document 1 is a Zn-Ni side of the plating layer structure of the alloy steel sheet of the Ni content is relatively high, the first layer, and the Ni content of the surface side is relatively low, the second layer, the thickness ratio of the two coating layer It discloses with respect to the control technology. However, Zn-Ni plated, if the bi-layer a first current density and plating time ratio of the second coating layer changes it is difficult to secure productivity there is a difficult problem commercial use.
[6]
[7]
Further, the Patent Document 2 is a nickel alloy plating layer in FIG analyze the residual stress behavior with increasing adhesion, low residual stress, a nickel alloy capable of simultaneously satisfying the high ductility is disclosed as 6.5-9.5%. According to Patent Document 2, a nickel alloy that also the ductility is reduced if it exceeds 9.5%, the ductility reduction by the internal stress sharply increases and stress is switched from the compression to the tension. However, the residual stress effects of nickel alloy nor not reflect the degree of residual stress changes in accordance with the case, the residual stress characteristics under the corrosive environment of the prepared specimen that is, penetrates into the interior of the coated layer of corrosion products of the surface cracking degree of the study the actual utilization can not fall.
[8]
[9]
(Patent Document 1) Japanese Unexamined Patent Publication Laid-Open Patent Publication No. 08-165594
[10]
Patent Document 2: US Patent No. 3420754 No.
[11]
Detailed Description of the Invention
SUMMARY
[12]
The present invention is to provide corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet and a method of manufacturing the same.
[13]
Problem solving means
[14]
One embodiment of the present invention possessing the steel sheet; And comprises a Zn-Ni plated layer formed on the possession of the steel sheet, the Zn-Ni plated layer on Ni alloy also has a 7.5 ~ 14%, from the interface of the hold plate and the Zn-Ni plated layer with the Zn-Ni plated layer direction 1 in the area within ㎛ Ni content to the service 40 to 50 atom% of the corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet.
[15]
[16]
Another aspect of the invention to prepare a carrying plate; And the nickel sulfate hydrate was immersed in the sulfuric acid bath at pH 1 ~ 5 of the carrying plate contains nickel sulfate hydrate and zinc sulfate monohydrate, and including the step of forming the Zn-Ni plated layer on the possession of a steel sheet, is 45 ~ 93g / L, and provides a process for the production of the zinc sulfate hydrate and nickel sulfate hydrate ratio 0.4 to 1.4 in corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet.
[17]
Effects of the Invention
[18]
According to the invention, relatively despite low nickel alloy also, and the corrosion resistance and workability is excellent, as well, not only the conventional Zn-Ni-plated steel sheet and a two-ply plated steel sheet prepared price competitive excellent, possible with high productivity obtained Zn-Ni It may provide an electroplated steel sheet.
[19]
Best Mode for Carrying Out the Invention
[20]
The following describes the present invention.
[21]
[22]
First, Zn-Ni alloy electroplated steel sheet of the present invention includes a Zn-Ni plated layer formed on the carrying plate and the hold plate. In this case, the Zn-Ni alloy plate layer on Ni also is preferably 7.5 ~ 14%. In the present invention, by controlling the Ni alloy is also as described above is electrochemically stable gamma (Ni 5 Zn 21 can be secured to a single phase), it is possible to improve the corrosion resistance with it. On the other hand, gamma-stage increase in the Ni alloy is also in phase region will lead to a sharp increase in the hardness of the coating layer. Therefore, this gamma-phase region Ni alloy also in consideration of the workability decreases and the corrosive environment residual stress change before and after the exposure, such as aqueous sodium chloride immersion, or salt spray environment due to the rapid plating hardness increase according to the increase in the appropriate range in FIG Ni alloy in it is necessary to set up. Ten thousand and one, Ni, if the alloying degree is less than 7.5%, the Eta phase (the same crystalline phase and the pure zinc) or eta + gamma mix onto the crystalline phase, such as the displayed thermal corrosion resistance for similar pure zinc or when, galvanically by the potential difference between the mixed the disadvantage is that corrosion is promoted to be the corrosion resistance column. Ni if the alloying degree is more than 14% has become the properties, such as while the corrosion resistance improving effect insignificant, and the manufacturing cost is increased, due to the rapid increase of the plating layer hardness after the coating adhesion, processability and processing corrosion resistance inferior problem. Therefore, Ni alloy diagram of the present invention is preferably 7.5 ~ 14%, and the Ni alloy is even more preferably 9-12% from the economic point of view.
[23]
[24]
Also, Zn-Ni plated steel sheet of the present invention electrical preferably possess the Ni content in the area of ​​the Zn-Ni plated layer within 1㎛ the direction from the interface of the steel sheet and Zn-Ni plated layer of 40 to 50 atomic%. Through this, corrosion and so is the zinc hydroxide formed on the surface of the steel sheet passivated upon progress, whereby the Ni-enriched layer is formed can be achieved an effect of conductivity delay the dehydration of a very large zinc oxide from zinc hydroxide, and ultimately as it is possible to improve the corrosion resistance. When the case where the Ni content is less than 40 atomic% had a disadvantage in corrosion resistance for heat difficult to retard the dehydration of a zinc oxide, is more than 50 atom% in or to a rather open in corrosion resistance to a high Ni content in the interface layer because there is a disadvantage that cracks are generated at the interface during processing, or the peeling interface layer. From the interface between the steel sheet and Zn-Ni plated layer possessing as the Zn-Ni plating Ni content of direction in the region of less than 1㎛ is more preferably 42-46% at.%.
[25]
[26]
On the other hand, r value (the plastic deformation coefficient (plastic strain ratio)) and the n-value (work-hardening exponent (work hardening coefficient)) are each deep draw moldability and extending (stretching) is an index used to predict the formability. Since the r-value is not less thickness variations during the molding of a large crack easily when material not occur it is possible to increase the depth of the formed cup. Therefore, if the two values ​​is large it can be said that formability of the steel sheet excellent. In the case of Zn-Ni alloy plated steel sheet Ni alloying degree of 10% is higher than the Vickers hardness of reference 300 is generated and the plating layer cracking during processing becomes plating layer distance of the penetration into the coating layer of the corrosion factors easily detached. In this case, due to the corrosion product generated due to the first eluted (Preferential dissolution) of the zinc plating layer cracking is to be accelerated in accordance with the increase in the corrosion environment exposure. In addition, gamma-stage increase in the Ni alloy phase region is to cause a rapid increase in hardness of the coating layer becomes vulnerable to the plating layer cracking during processing. In the present invention, Zn-Ni for workability prediction of the coated steel strip make the change in the value of r in accordance with another aspect coating weight by an increase in the coating weight was derived that they correspond to the reduction in the r value, the relatively high level in view of this, adequacy was the coating weight of the another one surface that is required in the front and a lower level of corrosion resistance required for the corrosion resistance.
[27]
[28]
To this, Zn-Ni electroplated steel sheet of the present invention, the adhesion amount of Zn-Ni plated layer formed on one surface of the carrying plate is a 20 ~ 50g / ㎡, coating weight of the Zn-Ni plated layer formed on the other surface of the carrying plate is the it is 0.25 to 0.8 times the coating weight of the Zn-Ni plated layer formed on one surface of the substrate plate times being preferred. If the if the amount of deposition of the Zn-Ni plated layer formed on one surface of the carrying plate is less than 20g / ㎡ has a drawback becomes degraded the corrosion resistance and susceptible to external damage to the scratch or the like, exceeding 50g / ㎡ has caused cracks, while the manufacturing cost is raised the deepening and there is an effect of improving corrosion resistance minor problems. Further, when the coating weight of the Zn-Ni plated layer formed on the other surface of the substrate steel sheet is less than 0.25 times the Zn-Ni plated layer coating weight formed on the surface of the carrying plate has a drawback that deterioration in corrosion resistance and coating weight control is difficult, exceeds 0.8 times there is a problem that a cost increase workability or formability effects negligible, if applicable.
[29]
[30]
In this way the Zn-Ni electroplated steel sheet of the invention can reduce the erosion rate of the Zn-based alloy the most important electrochemical reactivity in coated steel large Zn and corrosive environmental conditions, provided it is possible to maintain the sacrificial corrosion resistance to the possession of iron. Also, it is possible to minimize the post-processing in workability side through the coating weight adequacy material degradation and resulting property degradation.
[31]
[32]
It will be described in detail hereinafter, the production method of the present invention.
[33]
[34]
First, prepare the carrying sheet. The possession of the steel sheet is the cleanness of the surface can be secured through the pre-treatment process such as pickling or degreasing, is not particularly limited in the pre-treatment conditions in the present invention.
[35]
[36]
Thus, by immersing the prepared steel sheet possessing a sulfate bath at pH 1 ~ 5 to form a Zn-Ni plated layer on said carrying plate. Typically acid sexuality is an illustration of one due to the high electrical conductivity compared to the alkaline bath a high current efficiency, non-uniform in the thickness direction at a normal current density range of alloy element distribution. That is, the Zn-Ni alloy plated steel sheet produced in acid conditions, sexual desire is going to carry the steel sheet / Zn-Ni plating layer surface in the surface of the plating layer is exhibits a distribution such that the nickel content increases. Zn-Ni alloy electroplated steel sheet is corroded Ni-enriched layer (Ni-enriched layer) when progress is formed may suppress the corrosion, in the case of acid libido the Ni concentration in the possession of iron / coating layer interface relatively high Zn-Ni contributes to strengthening of the Ni-enriched layer enhanced the corrosion resistance of the coated steel strip mechanism. On the other hand, when the pH of the sulfate bath is less than 1, there is a disadvantage becomes a pH reduced by the operation time has elapsed during hydrogen production over increased susceptible to hydrogen embrittlement. On the other hand, if the pH exceeds 5, there is a disadvantage that the distribution becomes that carry the steel sheet / Zn-Ni plated layer going into the interface surface of the plating layer on the Ni content is increased little. In other words, the Ni-enriched layer formed on the effects of the possession of the steel sheet / Zn-Ni plated layer interface can mimihayeo detrimental to corrosion resistance. In addition, the securing of Fig Ni alloy target to slow down the dissolution rate of the nickel sulfate hydrate has the disadvantage that it is difficult This decreases productivity. The sulfuric acid bath pH is more preferably 1.5 to 3.
[37]
[38]
In addition, the sulfuric acid bath is preferably comprises nickel sulfate hydrate and zinc sulfate monohydrate, and at this time, the nickel sulfate hydrate is preferably 45 ~ 93g / L. The nickel sulfate hydrate is less than 45g / L, the Ni alloying degree, and this disadvantage becomes a low corrosion resistance inferior, 93g / if L exceeds, the Ni alloy also after workability or formability and machining to above the target value corrosion resistance inferior getting there is a disadvantage that the manufacturing costs increase. In addition, Ni alloy also target of 7.5 to cross in order to ensure a 14% zinc sulfate hydrate and nickel sulfate hydrate concentration ratio is required to be in the range of 0.4 to 1.4. On the other hand, the sulfuric acid bath is sodium sulfate (Na for adjusting conductivity of the plating solution 2 SO 4 may comprise a).
[39]
[40]
On the other hand, when forming the plating layer at the time of forming the coating layer, to a surface of the carrying plate Zn-Ni coating weight is 20 ~ 50g / ㎡ and, Zn-Ni coating weight is on the other side of the carrying plate it is preferable that 0.25 to twice to 0.8 times the coating weight of the Zn-Ni plating is applied to one surface of the carrying plate. As described above, it is possible to implement the effect of improving formability by controlling the coating weight. On the other hand, in order to form a plating layer of a different coating weight of the plating layer on both sides as described above, for example, by circulating a that after the plating solution where a carrying plate to the cathode of the electroplating simulator of vertical plating cell type Zn-Ni plated layer on a surface after having formed a, it is possible to use a method of forming a Zn-Ni plated layer in the same manner as described above in another aspect. Zn-Ni coating weight is attached to one surface of the carrying plate is more preferably from 20 ~ 40g / ㎡, Zn-Ni coating weight is attached to another aspect is a Zn-Ni coating weight is applied to one surface of the carrying plate it is more preferably 0.45 times to twice to 0.7.
[41]
[42]
After the step of forming the plating layer is up to reach the steel plate temperature: may further comprise the step of heating the (peak metal temperature PMT) based on 190 ~ 260 ℃. In the present invention, given the weak point on the residual stress caused by the nature of the low process temperature of the electroplating with a through a separate heating step ease the residual stress, and gamma decisions necessary for the corrosion resistance property as described above after the electroplating process It can be improved. Improvement in, the effects such as improvement of crystallinity of the retained strain relief and scale if the case where the heating temperature is lower than 190 ℃ there and is difficult due to insufficient amount of heat to be supplied to the steel sheet to achieve the effect described above, exceeds 260 ℃ on the other hand becomes insignificant degree because of a high temperature heating, there is a problem that yellowing occurs on the surface of the steel sheet. The heating temperature is more preferably 210 ~ 245 ℃.
[43]
[44]
On the other hand, the heater may utilize induction (induction heating) or a hot-air curing method. For the heat treatment, since the heating efficiency side, the steel sheet itself, rapid heating induction hardening method is relatively high as compared to the hot air curing method is heated at a slower rate by convection under the inductive magnetic field Zn-Ni plated steel sheet is more preferable to use an induction hardening method Do.
[45]
Mode for the Invention
[46]
It will be described in detail below, embodiments of the present invention. However, the invention is not limited to the following Examples.
[47]
[48]
(Example)
[49]
The thickness 0.8mm, width 140mm, 250mm vertical size carrying plate (ultra-low-carbon steel) degreasing and pickling a back, the following Table 1 the carrying plate by electroplating, and processing conditions as described in the heating to form a Zn-Ni plated layer . At this time, back to the carrying plates circulate in which after the plating solution is located in a cathode of an electroplating simulator of vertical plating cell type that forms a Zn-Ni plated layer on one side, the Zn-Ni plated layer in the same manner as described above in different embodiments It was controlled by varying the plating coverage on both surfaces of the substrate of the steel sheet forming. The plating current density is in the formation 100A / dm 2 , was the flow rate include the sodium sulfate was 1.5m / s, the bath contains sulfuric acid 30g / L. Further, heat treatment was performed using an induction hardening device.
[50]
[51]
TABLE 1
division Sulfuric acid bath conditions Plating conditions PMT based on the heating temperature (℃)
pH Zinc sulfate heptahydrate (g / L) Nickel sulfate hexahydrate (g / L) Zinc sulfate heptahydrate / nickel sulfate hexahydrate One surface plating time in seconds Another aspect plating time in seconds
Comparative Example 1 3 75.0 20.0 3.75 10 8.8 -
Comparative Example 2 3 65.0 45.0 1.44 10 8.8 -
Comparative Example 3 3 64.2 43.2 1.49 10 8.8 -
Examples 1 1 62.4 46.8 1.33 10 8.8 -
To honor two 3 62.4 46.8 1.33 10 8.8 -
To honor 3 5 62.4 46.8 1.33 10 8.8 -
Comparative Example 4 7 62.4 46.8 1.33 10 8.8 -
Comparative Example 5 9 62.4 46.8 1.33 10 8.8 -
To honor four 1 52.0 66.0 0.79 10 8.8 -
To honor five 3 52.0 66.0 0.79 10 8.8 -
To honor 6 5 52.0 66.0 0.79 10 8.8 -
Comparative Example 6 7 52.0 66.0 0.79 10 8.8 -
Comparative Example 7 9 52.0 66.0 0.79 10 8.8 -
To honor 7 1 46.1 78.6 0.59 10 8.8 -
To honor eight 3 46.1 78.6 0.59 10 8.8 -
To honor nine 5 46.1 78.6 0.59 10 8.8 -
Comparative Example 8 7 46.1 78.6 0.59 10 8.8 -
Comparative Example 9 9 46.1 78.6 0.59 10 8.8 -
To honor 10 1 38.9 92.7 0.42 10 8.8 -
To honor 11 3 38.9 92.7 0.42 10 8.8 -
To honor 12 5 38.9 92.7 0.42 10 8.8 -
Comparative Example 10 7 38.9 92.7 0.42 10 8.8 -
Comparative Example 11 9 38.9 92.7 0.42 10 8.8 -
Comparative Example 12 3 35.2 99.8 0.35 10 8.8 -
Comparative Example 13 3 28.0 114.0 0.25 10 8.8 -
Comparative Example 14 3 52.0 66.0 0.79 10 8.8 180
To honor 13 3 52.0 66.0 0.79 10 8.8 190
To honor 14 3 52.0 66.0 0.79 10 8.8 200
To honor 15 3 52.0 66.0 0.79 10 8.8 230
To honor 16 3 52.0 66.0 0.79 10 8.8 260
Comparative Example 15 3 52.0 66.0 0.79 10 8.8 270
Comparative Example 16 3 52.0 66.0 0.79 10 8.8 290
Comparative Example 17 3 52.0 66.0 0.79 4.0 10.0 -
To honor 17 3 52.0 66.0 0.79 7.5 5.8 -
To honor 18 3 52.0 66.0 0.79 10.0 8.8 -
To honor 19 3 52.0 66.0 0.79 13.9 7.5 -
To honor 20 3 52.0 66.0 0.79 17.0 5.0 -
Comparative Example 18 3 52.0 66.0 0.79 20.8 15.5 -
Comparative Example 19 3 52.0 66.0 0.79 10.0 2.0 -
To honor 21 3 52.0 66.0 0.79 10.0 2.8 -
To honor 22 3 52.0 66.0 0.79 10.0 4.0 -
To honor 23 3 52.0 66.0 0.79 10.0 5.8 -
To honor 24 3 52.0 66.0 0.79 10.0 7.5 -
To honor 25 3 52.0 66.0 0.79 10.0 8.8 -
Comparative Example 20 3 52.0 66.0 0.79 10.0 9.5 -

[52]
[53]
With respect to the Zn-Ni electroplated steel sheet manufactured as above Zn-Ni alloy plated layer in even, carry the steel sheet and Zn-Ni plating layer from the interface between the Zn-Ni plating Ni content of direction in the region of less than 1㎛, coating weight, It was measured and corrosion resistance and workability, and results thereof are illustrated in Table 2 below.
[54]
[55]
The corrosion resistance of the red rust is balsaengbunyul Teflon tape to a rear edge of the specimen cut to a size of 75 × 150mm (Nitto Denko Corp., NITOFLON, No.903UL) masking process, and the salt spray tester and the specimen STP-200 (SUGA Test Instruments in Co., Ltd., Japan) into the JIS (Japanese industrial standards (Japan industrial standards)) was conducted in such a manner as to stand along the Z 2371 (5% sodium chloride, and spray amount per hour 1-2ml, chamber temperature 35 ℃), as a result If the case of 0 to 10% when the ◎ (very good), and 10% greater than ~ 40% ○ (excellent), more than 40% to 70% of △ evaluate the (usually), × (poor) when the 70% excess It was.
[56]
[57]
The victim way of corrosion castle the specimen was evaluated in the corrosion potential by using a 20 × to a rear immersed in 30 ℃, 3.5% sodium chloride, cut to 20mm size Please potentiometer stat (potentiostat). Potentiometer stat equipment as was used with a 352 SoftCorr III with corrosion measurement software mounted 273A model (EG & G Princeton Applied Research, US). At this time, the reference electrode (reference electrode) and the counter electrode (counter electrode) with saturated Caro Mel electrode respectively: a (saturated calomel electrode SCE) and a high density of carbon electrode was used. Became 0.333mV / s applies to the scan velocity, corrosion potential was derived by extrapolation tapel (Tafel extrapolation method). If the immersion time, based on the 72 hours time point was compared to the corrosion potential for each condition compared to possession of iron compared to the electrochemical stability, that is, the sacrificial corrosion resistance, and as a result a low potential compared to possession of the steel sheet ○ (excellent), possession of the steel sheet and If the potential is equal to △ (normal), the steel sheet possessing high contrast potential was evaluated as × (poor).
[58]
[59]
After my powdering castle specimen of the workability was cut into 50 × 100mm size you given the jjibang tape (Nichiban CT-24) on the specimen surface, laying the specimen on a V-block press the specimen center pressing iron bending angle is 60 degrees after the tape from the specimen after applying a load, the end of the test was conducted in such a way within the off to determine whether the coating layer peeled off so. If the plated layer is peeled off, the US ○ when the separation (even number), the plating layer is evaluated as × (poor).
[60]
[61]
-R tension value of the processability after processing the sample with JIS 13B was calculated from the standard Instron 5582 (Instron Inc., USA) after the test at room temperature in a tensile tester at a tensile speed of 10mm per minute, 10-15% elongation range. If the heating treatment, based on the case of the enhanced degree of tension -r value that is not a sample of heat-treated specimens compared to greater than 60% when the ◎ (very good), greater than 30 ~ 60% ○ (excellent), 0 to If the 30% △ (usually) less than 0% (for the specimen prepared disadvantage not to heat treatment) was evaluated as × (poor), when varying the coating weight on both sides of the steel sheet, the reference sample a double-sided coating weight is If the increased amount of the same sample preparation tensile -r value to 30g / ㎡ than 20% when the ◎ (very good), greater than 5 ~ 20% ○ if the (solid), 0 ~ 5% △ (normal), 0 If the% less (when the coating weight on both sides of the same specimen disadvantage compared to 30g / ㎡) was evaluated as × (poor).
[62]
[63]
TABLE 2
division FIG alloy (%) Possession of the steel sheet and Zn-Ni Ni content in the area of ​​the Zn-Ni plated layer within 1㎛ direction from the interface of the plating layer (atomic%) A surface coating weight (g / ㎡) Another aspect coating weight (g / ㎡) Corrosion Workability
Red rust balsaengbunyul Sacrificial corrosion resistance Tensile values ​​-r My powder ringseong
Comparative Example 1 4.3 34.4 30 24 × × - ○
Comparative Example 2 6.4 36.3 30 24 △ △ - ○
Comparative Example 3 7.0 37.2 30 24 △ △ - ○
Examples 1 7.5 41.2 30 24 ○ ○ - ○
To honor two 7.5 41.7 30 24 ○ ○ - ○
To honor 3 7.5 41.9 30 24 ○ ○ - ○
Comparative Example 4 7.5 39.5 30 24 △ △ - ○
Comparative Example 5 7.5 39.4 30 24 △ △ - ○
To honor four 10.5 44.4 30 24 ○ ○ - ○
To honor five 10.5 44.3 30 24 ○ ○ - ○
To honor 6 10.5 44.1 30 24 ○ ○ - ○
Comparative Example 6 10.5 35.7 30 24 ○ △ - ○
Comparative Example 7 10.5 36.2 30 24 ○ △ - ○
To honor 7 12.0 46.0 30 24 ○ ○ - ○
To honor eight 12.0 45.9 30 24 ○ ○ - ○
To honor nine 12.0 46.2 30 24 ○ ○ - ○
Comparative Example 8 12.0 36.0 30 24 ○ △ - ×
Comparative Example 9 12.0 36.3 30 24 ○ △ - ×
To honor 10 14.0 48.8 30 24 ◎ ○ - ○
To honor 11 14.0 48.9 30 24 ◎ ○ - ○
To honor 12 14.0 49.1 30 24 ◎ ○ - ○
Comparative Example 10 14.0 38.9 30 24 ○ × - ×
Comparative Example 11 14.0 38.9 30 24 ○ × - ×
Comparative Example 12 15.0 50.5 30 24 ○ ○ - ×
Comparative Example 13 17.0 52.1 30 24 ○ × - ×
Comparative Example 14 10.5 44.3 30 24 ○ ○ △ ○
To honor 13 10.5 44.3 30 24 ○ ○ ○ ○
To honor 14 10.5 44.3 30 24 ◎ ○ ○ ○
To honor 15 10.5 44.3 30 24 ◎ ○ ○ ○
To honor 16 10.5 44.3 30 24 ◎ ○ ◎ ○
Comparative Example 15 10.5 44.3 30 24 ○ △ △ ○
Comparative Example 16 10.5 44.3 30 24 △ △ △ ×
Comparative Example 17 10.5 44.3 10 2 × × ◎ ○
To honor 17 10.5 44.3 20 15 ○ ○ ◎ ○
To honor 18 10.5 44.3 30 24 ○ ○ ○ ○
To honor 19 10.5 44.3 40 20 ○ ○ ○ ○
To honor 20 10.5 44.3 50 12.5 ○ ○ ○ ○
Comparative Example 18 10.5 44.3 60 30 △ × × ×
Comparative Example 19 10.5 44.3 30 4 ○ △ ○ ○
To honor 21 10.5 44.3 30 7.5 ○ ○ ○ ○
To honor 22 10.5 44.3 30 10 ○ ○ ○ ○
To honor 23 10.5 44.3 30 15 ○ ○ ○ ○
To honor 24 10.5 44.3 30 20 ○ ○ ○ ○
To honor 25 10.5 44.3 30 24 ○ ○ ○ ○
Comparative Example 20 10.5 44.3 30 26 ○ ○ △ ○

[64]
[65]
As it demonstrated by the above Tables 1 and 2, in the case of the invention examples 1 to 25 the invention satisfy the condition that the proposal has excellent corrosion resistance (red rust balsaengbunyul, the sacrificial cushion property) and processability (-r tension value, ringseong in powder) there may have to check.
[66]
[67]
However, the comparative example for 1 to 13, the Zn-Ni plating layer from the interface of my Ni alloy according to not meet the sulfuric acid bath conditions suggesting the present invention Zn-Ni plated layer, or possession of the steel sheet and Zn-Ni plated layer direction It is not to satisfy the conditions of the Ni content in the area within 1㎛ it can be seen that does not ensure an excellent level of corrosion resistance and workability.
[68]
[69]
In the case of Comparative Examples 14 to 16 it can be seen that this does not ensure a high level of corrosion resistance and workability according to the heating condition does not meet that proposed in the present invention at the same time.
[70]
[71]
In Comparative Examples 17 to 20 it can be seen that this does not ensure an excellent level of corrosion resistance and workability according to the coating weight does not satisfy the condition for the proposed invention.

Claims

[Claim 1]Possession steel; And comprises a Zn-Ni plated layer formed on the possession of the steel sheet, the Zn-Ni plated layer on Ni alloy also has a 7.5 ~ 14%, from the interface of the hold plate and the Zn-Ni plated layer with the Zn-Ni plated layer direction 1 in the area within ㎛ Ni content is 40 to 50 atom% of the corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet.
[Claim 2]
The method according to claim 1, coating weight of the Zn-Ni plated layer formed on one surface of the carrying plate 20 to a 50g / ㎡, coating weight of the Zn-Ni plated layer formed on the other surface of the steel sheet is in possession Zn- formed on one surface of the carrying plate Ni plating layer 0.25 times to 0.8 times the corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet of the deposit mass.
[Claim 3]
Preparing a steel sheet possession; And the nickel sulfate hydrate was immersed in the sulfuric acid bath at pH 1 ~ 5 of the carrying plate contains nickel sulfate hydrate and zinc sulfate monohydrate, and including the step of forming the Zn-Ni plated layer on the possession of a steel sheet, is 45 ~ 93g / L, and the method for producing the zinc sulfate hydrate and nickel sulfate hydrate ratio 0.4 to 1.4 in corrosion resistance and workability is excellent Zn-Ni electroplated steel sheet.
[Claim 4]
The method according to claim 3, further hour, the Zn-Ni coating weight of one surface of the carrying plate 20 ~ 50g / ㎡, and one surface of the carrying plate of the Zn-Ni coating weight of the another one surface of the carrying plate to form the coating layer Zn-Ni plating method of 0.25 times to 0.8 times the corrosion resistance and workability, superior electrical Zn-Ni plated steel sheet such that the coating weight to be applied to.
[Claim 5]
The method according to claim 3, after the step of forming the coating layer, a method of manufacturing the step of heating the steel sheet as the base reaches the maximum temperature 190 ~ 260 ℃ further includes excellent corrosion resistance and workability Zn-Ni electroplated steel sheet.
[Claim 6]
The method according to claim 5, wherein the heating process for producing a corrosion resistance and excellent workability, Zn-Ni electroplated steel sheet using a hot-air or induction hardening method.