The invention provides a copper-zinc alloy with low lead content useful in the manufacture of wire used in the manufacture of cages for aquaculture, where said wire suffers the least deterioration due to loss of zinc during exposure to stagnant water, water of little movement or sea waters.

The invention provides a copper-zinc alloy with low lead content useful in the manufacture of wire used in the manufacture of cages for aquaculture, where said wire suffers the least deterioration due to loss of zinc during exposure to stagnant water, water of little movement or sea waters.

A connection terminal having a copper alloy as a base material, the copper alloy comprising Zn in an amount of 21 mass % or more and 27 mass % or less, Sn in an amount of 0.6 mass % or more and 0.9 mass % or less, Ni in an amount of 2.5 mass % or more and 3.7 mass % or less, and P in an amount of 0.01 mass % or more and 0.03 mass % or less, and the balance being Cu and inevitable impurities, wherein the copper alloy has: a 0.2% proof stress of 620 MPa or higher and 700 MPa or lower, and an electrical conductivity of 15% IACS or higher and 20% IACS or lower.

A connection terminal having a copper alloy as a base material, the copper alloy comprising Zn in an amount of 21 mass % or more and 27 mass % or less, Sn in an amount of 0.6 mass % or more and 0.9 mass % or less, Ni in an amount of 2.5 mass % or more and 3.7 mass % or less, and P in an amount of 0.01 mass % or more and 0.03 mass % or less, and the balance being Cu and inevitable impurities, wherein the copper alloy has: a 0.2% proof stress of 620 MPa or higher and 700 MPa or lower, and an electrical conductivity of 15% IACS or higher and 20% IACS or lower.

A lead-free brass alloy contains 57.0 to 60.0% wt. Cu, 1.0 to 2.0% wt. Al, 1.5 to 2.5% wt. Mn, 0.1 to 1.0% wt. Fe, at most 0.5% wt. Ni, at most 0.5% wt. Sn, 0.5 to 2.0% wt. Si, less than 0.1% wt. Pb, balance Zn and also unavoidable impurities. Wherein the copper equivalent (CuEq) is in the range from 52.0 to 58.0%.

A lead-free brass alloy contains 57.0 to 60.0% wt. Cu, 1.0 to 2.0% wt. Al, 1.5 to 2.5% wt. Mn, 0.1 to 1.0% wt. Fe, at most 0.5% wt. Ni, at most 0.5% wt. Sn, 0.5 to 2.0% wt. Si, less than 0.1% wt. Pb, balance Zn and also unavoidable impurities. Wherein the copper equivalent (CuEq) is in the range from 52.0 to 58.0%.

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}≤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}.

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}≤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}.

A copper-zinc alloy contains 59.0 to 65.0% Cu, 2.5 to 4.0% Mn, 1.2 to 2.5% Al, 0.5 to 2.0% Si, 0.2 to 1.0% Fe, 0 to 1.0% Pb, 0 to 1.5% Ni, 0 to 0.2% Sn, balance Zn and unavoidable impurities. The zinc alloy has excellent temperature resistance and surfaces produced by machining have a considerably reduced surface roughness.

A copper-zinc alloy contains 59.0 to 65.0% Cu, 2.5 to 4.0% Mn, 1.2 to 2.5% Al, 0.5 to 2.0% Si, 0.2 to 1.0% Fe, 0 to 1.0% Pb, 0 to 1.5% Ni, 0 to 0.2% Sn, balance Zn and unavoidable impurities. The zinc alloy has excellent temperature resistance and surfaces produced by machining have a considerably reduced surface roughness.