JPS6234822B2 - - Google Patents

Description

[Detailed description of the invention]

[Objective] The present invention relates to a copper alloy having excellent deep drawing properties suitable for deep drawing. [Prior art and problems] Traditionally, copper and copper alloys have been used for deep drawing.
It is used for many purposes such as various industrial parts, miscellaneous goods, and accessories. In particular, brass, which is a copper-zinc alloy, is often used because it has relatively good deep drawability and is inexpensive. Generally, copper alloys for deep drawing are required to have the following properties. (1) The critical drawing ratio is high so that deep drawing can be achieved. (2) There should be no roughness on the product surface after deep drawing. (3) Less occurrence of selvage in deep drawn products. (4) Good thickness uniformity of deep drawn products. (5) The strength of deep drawn products is high. (6) Deep drawn products have stress corrosion cracking resistance and a long product life. All of the conventional brasses have advantages and disadvantages and cannot necessarily satisfy these various required characteristics. For example, in order to increase the critical drawing ratio of this brass, it is necessary to increase the crystal grain size, but in this case, the molded product will have rough skin and noticeable selvage, making it unsuitable as a deep-drawn material. Furthermore, the uniformity of plate thickness, strength, and resistance to stress corrosion cracking also deteriorate. On the other hand, if an attempt is made to improve the above-mentioned various properties by making the grain size finer, the critical drawing ratio decreases and deep drawability deteriorates. Furthermore, attempts were made to add additive elements to brass to satisfy these various properties, and one of them was ``On the deep drawability of phosphorous-containing brass'' (84th (1979) Japan Institute of Metals Spring Lecture Abstracts). P.249) reports that adding P to brass improves its deep drawability. However, when P is added, the formation of ears is as large as in brass, and this is still not completely satisfactory. [Structure of the Invention] In view of the above points, the present invention aims to improve the drawbacks of conventional brass and provide a copper alloy excellent in various deep drawing properties. The present invention has Zn10-42% by weight, P0.01-0.1% by weight,
Copper alloy for deep drawing and Zn10 containing 0.05 to 1.0% by weight of Sn, the balance being Cu and unavoidable impurities
The present invention relates to a copper alloy for deep drawing which contains 0.01 to 0.1% by weight of P, 0.01 to 0.1% by weight of Sn, and 0.05 to 1.0% by weight of Sn, with the remainder consisting of Cu and unavoidable impurities, and having a crystal grain size of 25μ or less. [Specific Description of the Invention] Next, the reasons for limiting the alloy components constituting the alloy of the present invention will be explained. The reason why the Zn content is set to 10 to 42% by weight is that if the Zn content is less than 10% by weight, the recrystallization orientation {110}, which is effective in improving deep drawability due to the inclusion of Zn, will not develop as much, resulting in poor deep drawability. There is a significant decrease in It also has the drawbacks of being expensive and having low strength. On the other hand, if the Zn content exceeds 42% by weight, the amount of β phase will increase and the processability will decrease. The reason why the Sn content is set to 0.05 to 1.0% by weight is that if the Sn content is less than 0.05% by weight, the deep drawability cannot be improved by these additive elements, and the formation of ears cannot be prevented. Conversely, if the Sn content exceeds 1.0% by weight, the processability during material production will decrease. The reason why the P content is set to 0.01 to 0.1% by weight is that the P content is 0.01
This is because if the P content is less than 0.1% by weight, the deep drawability cannot be improved by containing P, and on the other hand, if the P content exceeds 0.1% by weight, the workability during material production will decrease. Furthermore, the crystal grain size affects the skin properties of the product, but if the crystal grain size exceeds 25μ, rough skin will occur in deep drawn products, so the crystal grain size should be 25μ.
It is preferable to do the following. However, as mentioned above, this alloy has very good deep drawability, so even if the crystal grains of this deep drawn material exceed 25μ and some surface roughness occurs, it is still possible to use it for some products. It is. The alloy of the present invention will be explained below using examples. [Example] Ingots of various compositions of the alloy of the present invention shown in Table 1 were melted in a high-frequency melting furnace and heated to 800°C.
It was hot rolled into a plate with a thickness of 8 mm. Next, this plate was subjected to a conventional pickling treatment and then cold rolled to a thickness of 1.5 mm. After further annealing at 500°C for 1 hour, it was cold rolled into a plate with a thickness of 0.5 mm. This cold-rolled material was annealed at 400°C and 500°C for 1 hour to prepare a sample. As for the evaluation of the samples procured in this way, the strength of the material before molding, the crystal grain size, the limit drawing ratio, the surface roughness of the molded product, the height of the ears, etc. were shown. In addition, for the deep drawing test, a conical cup test was performed using a JIS conical cup test tool type 17 cylindrical flat bottom punch, and Kyoseki Sonic MT oil was used for lubrication.
6300 was used. The critical drawing ratio was determined using this deep drawing test method, and the edges of the molded product were measured using a tool microscope. (Aperture ratio 2.3) In addition, the presence or absence of surface roughness was visually inspected to judge whether it was good or bad. These results were combined with the comparative alloys in the first
Shown in the table. As shown in Table 1, the alloy according to the present invention exhibits a higher limit drawing ratio than conventional brass, exhibits excellent deep drawability, and does not cause surface roughness. On the other hand, brass with improved deep drawability has a rough surface. Furthermore, it can be seen that the height of the lugs of the molded product is high in conventional brass and brass to which P, Sn, Ni, Si, etc. are added alone, whereas the lugs in the alloy of the present invention are low and almost non-existent. In addition, it is clear that it has superior properties in all respects compared to conventional brass, such as no surface roughness and high material strength, and the alloy within the scope of the claims of the present invention is an optimal alloy for deep drawing. be.

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Claims (1)

[Claims] 1. Zn10-42% by weight, P0.01-0.1% by weight, Sn0.05
~1.0% by weight, with the remainder consisting of Cu and unavoidable impurities. 2 Zn10~42wt%, P0.01~0.1wt%, Sn0.05
~1.0% by weight, the remainder consisting of Cu and unavoidable impurities, and a crystal grain size of 25μ or less.