JP2007254848A - METHOD FOR MANUFACTURING MULTILAYER Ni-DIFFUSION PLATED STEEL SHEET - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer Ni-diffusion plated steel sheet comprising Ni plating on an unannealed cold roll steel sheet, diffusion annealing and then Ni or Ni alloy plating and to improve adhesiveness on the interface between the underlay Ni-diffusion plating layer and an overlay Ni or Ni alloy plating layer and to prevent press galling accompanying peeling of the plating layer upon press forming. <P>SOLUTION: The method for manufacturing a multilayer Ni-diffusion plated steel sheet comprises subjecting an unannealed cold-rolled sheet to non-gloss or semi-gloss Ni plating, and to diffusion annealing to form a Ni plating layer containing a Fe-Ni diffusion layer, then to non-gloss or semi-gloss or gloss Ni plating or Ni alloy plating. The method includes: degreasing, rinsing, pickling, rinsing and spraying with a Ni plating liquid prior to diffusion annealing as a pretreatment for the Ni plating before diffusion annealing; and pickling and spraying with a Ni or Ni alloy plating liquid after diffusion annealing as a pretreatment for the Ni or Ni alloy plating after diffusion annealing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a multilayer Ni diffusion plated steel sheet in which Ni or Ni alloy plating is performed after Ni plating is applied to a non-annealed cold-rolled steel sheet and diffusion annealing is performed. The present invention relates to a method for improving the adhesion at the interface of a Ni alloy plating layer.

  For plated steel plate materials used in battery cans, etc., the Fe-Ni diffusion layer or Fe-Ni diffusion layer and its upper layer are recrystallized and softened for the purpose of improving the corrosion resistance, battery characteristics, and surface slidability of the battery can. A multilayer Ni diffusion plated steel sheet having a Ni diffusion plating layer made of a Ni plating layer and further having a Ni plating layer or a Ni alloy plating layer as an upper layer is disclosed (for example, Patent Documents 1 to 6). The multi-layer Ni diffusion plated steel sheet is formed by subjecting a Ni diffusion plating layer to matte Ni plating on a non-annealed cold-rolled steel sheet and diffusion annealing, and matte, semi-glossy or glossy Ni on the upper layer of the Ni diffusion plating layer. It is disclosed to manufacture by plating or Ni alloy plating such as Ni—Co, Ni—P (for example, Patent Documents 1 to 4), and Ni—Co, Ni—P or the like is formed on the Ni diffusion plating layer. It is disclosed that the Ni alloy plating is performed (for example, Patent Documents 5 and 6). Further, it is disclosed that semi-bright Ni plating can be used as the Ni plating before the diffusion annealing (Non-Patent Document 1).

Japanese Patent Application Laid-Open No. 2003-277781 JP 2004-218043 A Japanese Patent Laying-Open No. 2005-085480 JP 2005-149735 A JP 2002-0503324 A JP 2004-068113 A Toyo Steel VOL. 29 pages 43-54

  Although the steel sheets of Patent Documents 1 and 2 have good performance, the adhesion between the lower Ni diffusion plating layer and the upper Ni or Ni alloy plating layer may not always be sufficient as the application range expands. As a result, a new problem has arisen that it is difficult to completely eliminate press galling associated with peeling of the plating during press working.

  In response to the above problems, the present inventor has intensively studied the factors that reduce the adhesion at the interface between the lower Ni diffusion plating layer and the upper Ni or Ni alloy plating layer. Unexpectedly, it was found that the pretreatment of the lower Ni plating affects the adhesion at the interface between the lower Ni diffusion plating layer and the upper Ni or Ni alloy plating layer. It was. That is, the gist of the present invention is that the unannealed cold-rolled steel sheet is subjected to matte or semi-gloss Ni plating and diffusion annealed to recrystallize the steel sheet, and the Ni plated layer is referred to as an Fe-Ni diffusion layer. Or a multi-layer Ni diffusion-plated steel sheet in which a Fe-Ni diffusion layer and an Ni plating layer recrystallized and softened on the Fe-Ni diffusion layer are formed and then matte, semi-gloss or gloss Ni plating, or Ni alloy plating is applied. In the method, as pretreatment of Ni plating before diffusion annealing, degreasing, rinsing, pickling, rinsing, Ni plating plating treatment before diffusion annealing is performed, and Ni or Ni alloy plating pretreatment after diffusion annealing Manufacture of a multilayer Ni diffusion plated steel sheet with good plating adhesion, characterized by performing a plating solution spray treatment of Ni or Ni alloy plating after pickling and diffusion annealing It is the law.

  The present invention makes it possible to improve the adhesion at the interface between the lower Ni diffusion plating layer and the upper Ni or Ni alloy plating layer in the production of the multilayer Ni diffusion plating steel sheet.

(Unannealed cold-rolled steel sheet)
The unannealed cold-rolled steel sheet as the plating base plate used in the present invention is preferably a component system that takes into account the processing of battery cans and the like, specifically, an ultra-low carbon steel sheet with Ti or Nb added alone or in combination, Or it is desirable that it is a low carbon Al killed steel plate.

(Pretreatment of Ni plating before diffusion annealing)
Next, pretreatment of Ni plating before diffusion annealing, which is one of the points of the present invention, will be described. As pretreatment, it is essential to perform degreasing, rinsing, pickling, rinsing, and plating solution spraying in this order. If the treatment here is inadequate, impurities such as oxides and hydroxides present in trace amounts on the steel sheet surface remain on the steel sheet and Ni plating interface after the subsequent Ni plating, and in this state, diffusion annealing is performed. As a result, the impurities move through Ni plating defects and Ni crystal grain boundaries, accumulate and concentrate on the outermost layer, and become a factor that hinders adhesion to Ni or Ni alloy plating applied to the upper layer. What is important here is that even a very small amount of impurities that do not inhibit the adhesion between the steel plate and the Ni plating interface is concentrated in the Ni diffusion plating surface layer by the subsequent diffusion annealing treatment, and Ni applied to the upper layer. Or it is a point which inhibits adhesiveness with Ni alloy plating. That is, it is common knowledge that pretreatment is generally important for normal plating, but in the production of a multilayer Ni diffusion plated steel sheet as in the present invention, the importance is further increased.

Specific conditions for good pretreatment are described below. First, as degreasing, treatment with an alkaline aqueous solution is desirable, and degreasing with an organic solvent that may be generally used does not cause any problem in the adhesion of the steel plate-Ni plating interface, Ni or Ni alloy plating of the upper layer- This is not preferable because the adhesion between the lower Ni diffusion plating layers tends to decrease. More specifically, the treatment with the alkaline aqueous solution is most preferably electrolytic treatment at a temperature of about 50 to 80 ° C. with a NaOH aqueous solution of about 10 to 200 g / l. As electrolysis conditions, a treatment of 1 to several tens of seconds at a current density of about 1 to 20 A / dm ² is desirable. Rinse after degreasing is generally performed, and is necessary to bring the degreasing solution into the pickling solution and prevent the pickling ability from deteriorating.

As pickling, electrolytic treatment in a sulfuric acid aqueous solution is desirable, and it is desirable to perform electrolytic treatment in a sulfuric acid aqueous solution of about 10 to 200 g / l at a temperature of room temperature to about 60 ° C. At this time, the polarity of electrolysis is important, and the polarity of the steel sheet must be the cathode. It is also preferable to obtain a clean surface by performing electrolysis while switching the polarity of the steel sheet and using the final polarity as the cathode. Here, when the last polarity is the anode, the oxide film tends to remain, which is not preferable. The current density during electrolysis is preferably about 1 A / dm ^{2 to} 20 A / dm ² , and the processing time is preferably 1 to 60 seconds.

  Rinse after pickling is generally performed, and is necessary to bring the pickling solution into the plating solution and suppress the fluctuation of the plating solution concentration. In addition to this, in the process of the present invention, when Ni plating is performed while Fe ions inevitably mixed in the pickling solution remain on the surface of the steel sheet, the adhesion at the interface between the steel sheet and Ni plating is not hindered. Then, since the adhesion with the Ni plating applied to the upper layer after the subsequent diffusion annealing treatment is hindered, it is necessary to remove this by rinsing.

After rinsing, the plating solution is sprayed. This treatment removes Fe ions that could not be removed by rinsing as described above from the surface of the steel sheet, or a small amount of oxidation regenerated on the surface during rinsing. Without this treatment, the adhesion at the interface between the steel sheet and the Ni plating is not hindered, but the Ni or Ni alloy applied to the upper layer after the subsequent diffusion annealing treatment is necessary. This will impede adhesion to the gold plating. The treatment liquid here is preferably the same as the subsequent Ni plating liquid in terms of suppressing fluctuations in the plating bath concentration. The plating solution spraying treatment is preferably performed for 1 second or longer with a liquid amount of 1 liter / m ² or more per side.

(Ni plating before diffusion annealing)
Any commonly used Ni plating can be used without particular limitation, but from the viewpoint of cost and the like, electroplating by a watt bath is desirable, and matte Ni plating or semi-gloss Ni plating can be applied. It is desirable to apply Ni plating on both sides, and it is also possible to apply Ni plating of different thicknesses on the front and back sides.

(Diffusion annealing treatment)
In the diffusion annealing treatment after Ni plating, recrystallization annealing of the steel plate and formation of the Ni diffusion plating layer are performed. The Ni diffusion plating layer means a Fe—Ni diffusion layer or a plating layer having a Fe—Ni diffusion layer and an Ni plating layer recrystallized and softened thereon. Specifically, the diffusion annealing treatment is performed in an inert gas or reducing gas atmosphere at a temperature of about 700 to 850 ° C. for a soaking time of about 20 to 60 seconds. Here, when considering the corrosion resistance of the finally obtained steel sheet, only a part of the Ni plating layer may be an Fe—Ni diffusion layer, and the re-softened Ni plating layer may remain on the surface layer. desirable.

(Pretreatment of Ni or Ni alloy plating after diffusion annealing)
Next to the diffusion annealing treatment, Ni or Ni alloy plating is performed again. The pretreatment at this time is also one of the points of the present invention, which will be described below. As pretreatment, it is essential to perform pickling and plating solution spray treatment in this order. If the treatment here is insufficient, impurities such as oxide accumulated and concentrated on the outermost layer during the diffusion annealing treatment cannot be removed, and the adhesion with Ni or Ni alloy plating applied to the upper layer is hindered. It becomes a factor.

  The pickling and plating solution spray treatment is performed in the same manner as the pretreatment of Ni plating before diffusion annealing described above, but the difference from the pretreatment in Ni plating before diffusion annealing is that the first is Degreasing and rinsing are not necessary, and the second is that rinsing after pickling is not necessary. The degreasing and rinsing treatments may be carried out, and it is preferable to carry out the degreasing and rinsing treatments when there is a possibility that dirt such as oil adheres in the steps after the diffusion annealing, but it is not essential.

  On the other hand, it is desirable not to carry out the rinse treatment after pickling. This is because the surface from which impurities have been removed by the pickling treatment may again form an inert surface such as an oxide or hydroxide during the rinsing treatment. Therefore, it is desirable to perform plating solution spray treatment without rinsing after pickling treatment, but in this case, the pickling solution is brought into the plating solution to avoid problems such as complicated plating solution concentration management. In order to do this, after the pickling, after squeezing with a roll, the plating solution spray treatment is performed, or the pickling is divided into a plurality of parts, the normal treatment is performed in the first pickling, and then diluted about 5 to 10 times. It is possible to adopt a method such as pickling again with a solution and a plating solution spray treatment.

  As preferable conditions for the pickling conditions, the conditions already described as preferable conditions for the pickling treatment in the Ni plating pretreatment before diffusion annealing can be applied.

As the plating solution spray treatment after pickling, it is desirable to use the same Ni or Ni alloy plating solution as that used in the sense that the variation in the plating bath concentration is suppressed. The plating solution spray treatment is desirably performed for 1 second or more with a liquid amount of 1 liter / m ² or more per side.

(Ni or Ni alloy plating after diffusion annealing)
Ni plating after the above pretreatment can be used without particular limitation, but from the viewpoint of cost and the like, electroplating with a watt bath is desirable. For the purpose of increasing the surface hardness, electroplating using a watt bath containing a glossy or semi-glossy additive is also used. Also, Ni alloy plating such as Ni-Co, Ni-P is used. Here, the Ni or Ni alloy plating can be performed on both sides, only on one side, or on both sides. If Ni or Ni alloy plating is performed on only one side, the above-described pretreatment for Ni or Ni alloy plating may be performed only on the surface to be plated.

(Temper rolling)
It is also suitable to correct the shape by roll rolling and adjust the surface roughness after the above-mentioned multi-layer plating treatment.

  Samples were manufactured in the order of lower layer Ni plating ⇒ diffusion annealing treatment ⇒ upper layer Ni plating ⇒ temper rolling, using a cold-rolled, non-recrystallized steel plate (NbTi-SULC steel) with a plate thickness of 0.3 mm as a plating base plate.

  First, as pretreatment for the lower layer Ni plating, degreasing, rinsing, pickling, rinsing, and plating solution spraying were performed in this order. Liquid squeezing was performed with a roll between each step. For degreasing, immersion treatment was carried out at 50 g / l NaOH aqueous solution at 70 ° C. for 10 seconds (“std” in Table 1). After degreasing, rinsing treatment was performed for 5 seconds with room temperature tap water (“std” in Table 1).

About pickling, it processed at normal temperature using 70 g / l sulfuric acid aqueous solution (impurity Fe ion is 3 g / l). Various processing conditions were changed as shown in Table 1. In Table 1, “A” means electrolysis using a steel plate as an anode, and “C” means electrolysis using a steel plate as a cathode. “ACAC” means repetition of anode → cathode → anode → cathode. Numerical values in parentheses indicate electrolysis current density A / dm ² . In Example 6, dip pickling was performed instead of electrolysis. The rinse treatment after pickling was performed for 5 seconds with room-temperature tap water (“std” in Table 1).

The plating solution spray treatment is a matte Watt bath (sulfuric acid Ni: 300 g / l, Ni chloride: 70 g / l, boric acid: 70 g / l) at 60 ° C., with a liquid volume of 1 liter / m ² per side for 2 sec. Went. In Comparative Examples 2, 4, 7, 9, and 10, this treatment was not performed. In Comparative Example 8, the dipping process was performed for 2 seconds instead of the spray process.

For the lower layer Ni plating, electrolysis was performed at 60 ° C. using the matte Watt bath described above to deposit 18 g / m ² of Ni. In Examples 11 and 13 and Comparative Examples 6, 7, and 10, 9 g / m ² of Ni was electrodeposited.

  After Ni plating, rinsing with tap water and drying, diffusion annealing was performed. In a non-oxidizing atmosphere, the Ni layer is heated to 800 ° C., soaked for 40 seconds, and then cooled to room temperature, so that a part of the Ni plating layer is Fe—Ni diffusion layer and recrystallized and softened on the surface layer. A Ni diffusion plating layer was formed, with the remaining. In Examples 11 and 13 and Comparative Examples 6, 7, and 10, a Ni diffusion plating layer was formed in which all of the Ni plating layer was an Fe—Ni diffusion layer.

  As pretreatment for the upper layer Ni plating, pickling and plating solution spraying were performed in this order. Liquid squeezing was performed with a roll between each step. In Examples 9 and 10, degreasing and rinsing were performed (the same processing conditions as in the pretreatment for the lower Ni plating).

  In Examples 8 and 10, instead of rinsing after pickling, a 10 g / l sulfuric acid aqueous solution was treated at room temperature for 5 seconds. Moreover, in the comparative example 1, the process for 5 seconds was performed with the normal temperature tap water as the rinse process after pickling.

  The pickling was performed at room temperature using a 70 g / l aqueous sulfuric acid solution (impurity Fe ions were 3 g / l). Various processing conditions were changed as shown in Table 1. The polarity symbol is the same as described above.

The plating solution spray treatment is performed at a temperature of 60 ° C. with a wet bath containing a semi-gloss additive (sulfuric acid Ni: 300 g / l, Ni chloride: 70 g / l, boric acid: 70 g / l, semi-gloss additive 1.5 g / l), The treatment was performed for 2 seconds at a liquid volume of 1 liter / m ² per side. In Comparative Examples 3, 4, 6, 7, 9, and 10, this treatment was not performed. In Comparative Example 8, the dipping process was performed for 2 seconds instead of the spray process. As the semi-gloss additive, a commercially available acetylene compound was used. In Examples 12 and 13 and Comparative Examples 9 and 10, a phosphorous acid-added Watt bath (sulfuric acid Ni: 300 g / l, Ni chloride: 70 g / l, boric acid: 70 g / l, phosphorous acid 20 g / l) The temperature was set to 60 ° C. and the same treatment was performed.

The upper layer Ni plating was electrolyzed at 60 ° C. using a Watt bath containing the same semi-gloss additive as described above, or a phosphorous acid-added Watt bath (Examples 12 and 13 and Comparative Examples 9 and 10), and 5 g / m. ² Ni was electrodeposited. In Example 11 and Comparative Examples 6 and 7, 15 g / m ² of Ni was electrodeposited. In Example 12 and Comparative Example 9, P5% Ni—P plating was 5 g / m ² as Ni, and in Example 13 and Comparative Example 10, P5% Ni—P plating was 15 g / m ² as Ni. I let you.

  After Ni plating, rinsing with tap water and drying, temper rolling with an elongation of 0.3% was performed with dull roll.

The adhesion evaluation method was performed as follows.
(1) Strip tape peeling: 100 mm grids with a spacing of 2 mm were brazed with a cutter, the tape was attached and peeled, and the adhesion was visually evaluated.
(2) Cross cut Eriksen tape peeling: The above cross cut sample was further subjected to an Erichsen 5 mm overhanging process, the tape was attached and peeled off, and the adhesion was visually evaluated.
(3) Cup molding peeling: 20mmφ cylindrical cup molding is performed, and the side of the cup and the mold are peeled off with tape and visually observed for peeling, and the cup side is observed with a magnifying glass and SEM (both inside and outside) Evaluated.

  In each case, “No” was evaluated as “◯”, “Slight” was evaluated as “△”, and “No” was evaluated as “×”.

  The results are shown in Table 1, and all the examples of the present invention showed good adhesion. In the comparative examples, those evaluated as Δ and x were peeling at the interface between the lower Ni diffusion plating and the upper Ni or Ni alloy plating.

  According to the present invention, in a method of manufacturing a multilayer Ni diffusion plated steel sheet in which Ni or Ni alloy plating is performed after Ni plating is applied to an unannealed cold-rolled steel sheet and diffusion annealing is performed, the lower Ni diffusion plating layer and the upper Ni or Since it becomes possible to improve the adhesion at the interface of the Ni alloy plating layer, it is possible to expand the application range of the multilayer Ni diffusion plated steel sheet having excellent corrosion resistance, battery characteristics, surface slidability, etc. This contributes to higher performance and lower cost of battery cans.

Claims (6)

The non-annealed cold-rolled steel sheet is matte or semi-gloss Ni-plated and diffusion-annealed to recrystallize the steel sheet, and the Ni-plated layer is an Fe-Ni diffusion layer, or an Fe-Ni diffusion layer and In the manufacturing method of the multilayer Ni diffusion plated steel sheet, in which the Ni plating layer is recrystallized and softened on the upper layer, and then matte, semi-gloss or glossy Ni plating, or Ni alloy plating is performed.
As pre-treatment of Ni plating before diffusion annealing, degreasing, rinsing, pickling, rinsing, Ni plating plating spray treatment before diffusion annealing,
Multi-layer Ni with good plating adhesion, characterized by performing pickling treatment, plating solution spray treatment of Ni or Ni alloy plating after diffusion annealing as pretreatment of Ni or Ni alloy plating after diffusion annealing A method of manufacturing a diffusion plated steel sheet.   The method for producing a multilayer Ni diffusion-plated steel sheet according to claim 1, wherein as a pickling treatment as a pretreatment in Ni plating before diffusion annealing, electrolysis is carried out in a sulfuric acid aqueous solution using the polarity of the steel sheet as a cathode.   2. The multilayer Ni according to claim 1, wherein as a pickling treatment as a pretreatment in Ni plating before diffusion annealing, electrolysis is performed while switching the polarity of the steel sheet in an aqueous sulfuric acid solution, and the last polarity is used as a cathode. A method of manufacturing a diffusion plated steel sheet.   4. The compound according to claim 1, wherein as a pickling treatment as a pretreatment in Ni or Ni alloy plating after diffusion annealing, the polarity of the steel sheet is electrolyzed in a sulfuric acid aqueous solution as a cathode. 5. Manufacturing method of layer Ni diffusion plating steel plate.   The pickling treatment as a pretreatment in Ni or Ni alloy plating after diffusion annealing is performed by electrolysis while switching the polarity of the steel sheet in an aqueous sulfuric acid solution, and the last polarity is used as a cathode. 4. A method for producing a multilayer Ni diffusion plated steel sheet according to any one of 3 above. The multi-layer Ni diffusion plated steel sheet according to any one of claims 1 to 5, wherein the plating solution spray treatment is a liquid amount of 1 liter / m ² or more per side and the treatment time is 1 second or more. Manufacturing method.