Dowa Metaltech Co., Ltd.

Naota Higami

Hiroto Narieda

Takanobu Sugimoto

Kazuki Yoshida

Tomotsugu Aoyama

There are provided an inexpensive copper alloy plate having excellent bending workability, excellent stress corrosion cracking resistance and excellent stress relaxation resistance while maintaining the high strength thereof, and a method for producing the same. The copper alloy plate has a chemical composition which contains 17 to 32% by weight of zinc, 0.1 to 4.5% by weight of tin, 0.5 to 2.0% by weight of silicon, 0.01 to 0.3% by weight of phosphorus and the balance being copper and unavoidable impurities, wherein the total of the content of silicon and six times as much as the content of phosphorus is 1% by weight or more and wherein the copper alloy plate has a crystal orientation satisfying I{220}/I{420}&#x2264;2.0 assuming that the X-ray diffraction intensity on {220} crystal plane on the plate surface of the copper alloy plate is I{220} and that the X-ray diffraction intensity on {420} crystal plane thereon is I{420}.

Copper alloy plate and method for producing same

An inexpensive sheet material of a copper alloy has excellent bending workability and excellent stress corrosion cracking resistance while maintaining high strength. The sheet material is produced by a method including melting and casting raw materials of a copper alloy which has a chemical composition having 17 to 32 wt. % of zinc, 0.1 to 4.5 wt. % of tin, 0.01 to 2.0 wt. % of silicon, 0.01 to 5.0 wt. % of nickel, and the balance being copper and unavoidable impurities; hot-rolling the cast copper alloy at 900&#xb0; C. to 400&#xb0; C.; cooling the hot-rolled copper alloy at 1 to 15&#xb0; C./min. from 400&#xb0; C. to 300&#xb0; C.; cold-rolling the cooled copper alloy; recrystallization-annealing the cold-rolled copper alloy at 300 to 800&#xb0; C.; and then, ageing-annealing the recrystallization-annealed copper alloy at 300 to 600&#xb0; C.

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Tokyo, Japan

Naota Higami