JPS622025B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for manufacturing nickel-plated copper-based alloys (including copper), and more specifically, to crystal oscillator cans, transistor caps, battery cases, buttons, and decorative items. The present invention relates to a method for producing a copper-based alloy that is suitable for deep-drawn products such as, etc., and in particular has fewer selvages during deep-drawing and does not cause cracking or peeling of the nickel plating layer. [Prior art] Generally, nickel silver has been mainly used for the caps of crystal resonators and transistors, but the surface of the product is plated with nickel in consideration of its corrosion resistance and stress corrosion cracking resistance. Ta. In addition, buttons, ornaments, etc. were deep drawn and nickel plated to improve their corrosion and abrasion resistance. Furthermore, the battery case is made of iron after deep drawing.
Products with nickel plating on both sides have been used. In this way, crystal oscillator caps, transistor caps, battery cases, buttons, decorative items, etc. are plated with nickel after deep drawing, but due to their complex shapes, the plating layer is difficult to coat. This results in non-uniformity, lowering the yield, and requiring a lot of time for plating, resulting in very low productivity. [Problems to be Solved by the Invention] As explained above, the present invention has been made in view of the problems caused by applying nickel plating after deep drawing of various shapes in the prior art. That is, as a result of intensive research by the present inventors, a nickel-plated copper-based alloy strip that can be deep-drawn without the plating peeling off has been developed. He developed a method for manufacturing it. [Means for Solving the Problems] The method for producing a nickel-plated copper-based alloy according to the present invention is characterized by applying nickel plating to a thickness of 0.5 to 10 μm on a copper or copper-based alloy strip. alms,
After annealing for 5 to 30 seconds at a temperature of 500 to 800 °C, and then cold rolling by 25 to 45%,
The method consists of annealing at a temperature of 800°C for 5 to 30 seconds. Therefore, this is a method for producing a nickel-plated copper-based alloy strip that has a selvage ratio of 2% or less, has good deep drawing workability, and does not cause peeling of the plating. The method for producing a nickel-plated copper-based alloy according to the present invention will be described in detail below. A detailed explanation of (1) plating thickness, (2) annealing temperature and time, (3) cold rolling, and (4) annealing temperature and time in the method for producing a nickel-plated copper-based alloy according to the present invention. do. (1) Regarding plating thickness. The reason why the lower limit of the nickel plating thickness was suppressed to 0.5μ was that the plating thickness was maintained at least 0.3μ through subsequent cold rolling and deep drawing, thereby improving the corrosion resistance and stress resistance of nickel. This is in order to exhibit corrosion cracking resistance, and the reason why the upper limit of the nickel plating thickness was set at 10 μm is because the corrosion resistance and stress corrosion cracking resistance will not improve significantly if the thickness is higher than that, and it is economically disadvantageous. It's a waste. Therefore, the thickness of the nickel plating should be 0.5 to 10μ. (2) Regarding annealing temperature and annealing time. Immediately after applying nickel plating, heat at 500 to 800℃.
Annealing is performed for 5 to 30 seconds at a temperature of
The nickel plating layer does not soften even after 30 seconds.
Cracks occur in the plating layer during subsequent rolling, and
The copper-based alloy strip itself does not soften, and the annealing temperature is 800℃.
If the holding time exceeds 5 seconds, the nickel plating layer and the base copper alloy strip will be sufficiently softened, but it will be a waste of energy, and furthermore, the oxide film on the nickel plating layer will become hard and dense, making it difficult to remove by pickling. It is difficult and uneconomical. Next, the reason why the annealing time was set at the lower limit of 5 seconds is because if it is less than 5 seconds, the temperature distribution in the thickness direction of the copper-based alloy strip during annealing will be uneven.
The center part is not softened, and the strength and elongation after softening become different between the center part and the ends, and annealing for more than 30 seconds is not preferable from the viewpoint of productivity. (3) Regarding cold rolling. The working ratio of cold rolling after annealing is preferably 25 to 40%, which is necessary to keep the selvage ratio at 2% or less during deep drawing of copper-based alloy strips.
%, the nickel plating layer on the surface is likely to cause local cracking and peeling, and furthermore, this cold rolling drastically reduces the voids contained in the nickel plating layer, making it difficult to cover the nickel foil. As a result, corrosion resistance and stress corrosion cracking resistance are improved. Therefore, cold rolling is performed at a processing rate of 25 to 40%. (4) Final annealing temperature and time. This final annealing is an essential heat treatment process for softening the nickel plating layer and the copper-based alloy strip, strengthening the adhesion between the plating layer, and reducing the selvage rate generated during deep drawing to 2% or less. The annealing temperature and time are exactly the same as explained in (1) annealing temperature and annealing time. In addition, as the target copper or copper-based alloy strip in the method for manufacturing the nickel-plated copper-based alloy strip according to the present invention, any copper or copper-based alloy strip that is suitable for deep drawing and has good formability can be used. Alloys may be used, but a typical example is CDA72500 (Cu-9wt
%Ni-2.3wt%Sn), JIS C7521(Cu-18wt%Ni
-18wt%Zn) and JIS C2680 (Cu-35wt%
Zn), etc. For nickel plating, it is best to use electroplating in order to prevent the contamination of phosphorus and other impurity elements and to plate copper alloy strips.As an electroless acid nickel plating bath, The essential ingredients are nickel chloride or nickel sulfate and sodium hypophosphite, including sodium hypophosphite, sodium oxyacetate, sodium acetate, sodium citrate,
Examples include those containing sodium succinate, malic acid, boric acid, etc. Electroless alkaline nickel plating baths include those containing nickel chloride, sodium hypophosphite, and ammonium chloride as essential components. It will be done. However, in these electroless plating methods, since hypophosphorous acid is used, the P content in the nickel plating layer is 4 to 5 wt%.
Given the above, electroless plating is not recommended from the perspective of waste disposal. That is, examples of electrolytic plating baths include Watt baths containing nickel sulfate, nickel chloride, boric acid, and the like. [Example] Examples of the method for manufacturing a nickel-plated copper-based alloy strip according to the present invention will be described. Examples CDA72500, JISC7521, and JISC2680 copper-based alloy strips with a processing rate of 60% or more were cleaned with a sulfuric acid-hydrogen peroxide mixture, and then subjected to alkaline electrolytic degreasing to produce nickel sulfate 300g/nickel chloride 45g/ The samples shown in Table 1 were prepared by electroplating using a Watts bath containing 35 g of boric acid.

[Table] The samples shown in Table 1 were tested under the conditions shown in Table 2.
It was annealed in a saltpeter furnace at a temperature below 500°C and in a salt bath furnace at a temperature above 500°C, and then rolled to a thickness of 0.60 mm, and the condition of the nickel plated layer after rolling was investigated.

[Table] Samples Nos. 1, 2, 3, 4, 5, and 6 were annealed at a temperature of 650℃ for 20 seconds after nickel plating, and samples Nos. 7, 8, and 9 were annealed at 600℃.
Heat treatment was performed for 15 seconds at a temperature of
For samples No. 1 to 6, at a temperature of 650℃ for 20 seconds,
Samples Nos. 7 to 9 were subjected to final annealing at a temperature of 600° C. for 15 seconds. The sample thus prepared was deep drawn using an Erichsen testing machine. The blank diameter of the sample was 71.7 mm, the aperture was set as 54%, the punch diameter was 33.0 mm, the punch radius was 4.5 mm, and the die diameter was
34.5mm, die radius 3.0mmR, wrinkle pressing pressure 200Kg, lubricating oil was diluted 1:3 with Johnson wax and water, and a drawing product was prepared and evaluated at a drawing speed of 7.8mm/sec. The average peak height Hmm and average valley depth hmm of the produced drawing material were measured, and the selvage rate was calculated by (H-h)/{(H+h)/2}×100(%). The results are shown in Table 3.

〔Effect of the invention〕

As explained above, since the method for manufacturing a nickel-plated copper-based alloy strip according to the present invention has the above-mentioned configuration, the manufactured product does not have cracks, and has no plating. It is an excellent material with no peeling of layers, has excellent corrosion resistance and stress corrosion cracking resistance, and can omit the plating process after deep drawing, resulting in excellent productivity. It is something that you have.

Claims (1)

[Claims] 1 Nickel plating with a thickness of 0.5 to 10μ is applied to a copper or copper-based alloy strip, annealed at a temperature of 500 to 800°C for 5 to 30 seconds, and then cold rolled by 25 to 45%. 1. A method for producing a nickel-plated copper-based alloy with an selvedge ratio of 2% or less, good deep drawing workability, and no peeling of the plating, which is characterized by annealing for 5 to 30 seconds at a temperature of 500 to 800°C.