Miyoshi Gokin Kogyo Co., Ltd.

Ihi Corporation

Mutsuki Ishijima

Masato Arai

Genjiro Hagino

Yuta Arai

Hayao Eguchi

Yoshihito Ogasawara

Shintaro Fujii

Masaaki Yamane

Hideharu Ito

A wear-resistant copper-zinc alloy includes in mass %, 28 to 55% Zn, 0.5 to 2% P, and a balance of Cu and unavoidable impurities, and the wear-resistant copper-zinc alloy has an electrical conductivity of 10 to 33% IACS and a hardness of 3.6[Zn]-55 HBW or more, where [Zn] denotes the Zn content in mass %. Alternatively, a wear-resistant copper-zinc alloy includes in mass %, 40 to 55% Zn, 1 to 6% Mn, and a balance of Cu and unavoidable impurities, and the wear-resistant copper-zinc alloy has an electrical conductivity of 10 to 33% IACS and a hardness of 3.6[Zn]-55 HBW or more, where [Zn] denotes the Zn content in mass %.

Wear-resistant copper-zinc alloy and mechanical device using same

Provided is a copper alloy tube that is a drawn tube made from a CuCrZr alloy which suppresses the deterioration of mechanical strength and, in particular, the coarsening of crystal grains even in a temperature zone of a solutionizing treatment, and is thus excellent in high-temperature brazeability, as well as the manufacturing method therefor. The manufacturing method comprises a solutionizing step of heating and holding a tubular extrusion material at a solutionizing temperature of 900&#xb0; C. or greater and then water-quenching the tubular extrusion material; a main process step comprising a set of steps including a drawing process step of drawing the tubular extrusion material, and an intermediate annealing step of heating at an annealing temperature and then water-quenching the drawn material; and an adjusting process step of further drawing the drawn material and setting average crystal grain sizes in a vertical cross section along an axis as well as a horizontal cross section orthogonal to the axis to 50 &#x3bc;m or less each. The average crystal grain sizes of the vertical cross section and the horizontal cross section are each set to 100 &#x3bc;m or greater and the annealing temperature is set to 900&#xb0; C. or greater after the solutionizing step, thereby making it possible to make the average crystal grain sizes of the vertical cross section and the horizontal cross section 100 &#x3bc;m or less after the adjusting process step, even if heating is performed at at least 980&#xb0; C. for 30 minutes followed by air-cooling.

Copper alloy tube with excellent high-temperature brazeability and manufacturing method therefor

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Tokyo, Japan

Mutsuki Ishijima