Abstract: By enhancing a stress corrosion cracking resistance in a leadless brass alloy, specifically by suppressing a velocity of propagation of corrosion cracks in the brass alloy, a straight line crack peculiar to the leadless brass alloy is suppressed, a probability of cracks coming into contact with ? phases is heightened and local corrosion on the brass surface is prevented to suppress induction of cracks by the local corrosion, thereby providing a leadless brass alloy contributable to enhancement of the stress corrosion cracking resistance. The present invention is directed to an Sn-containing Bi-based, Sn-containing Bi+Sb-based or Sn-containing Bi+Se+Sb-based leadless brass alloy excellent in stress corrosion cracking resistance, having an ?+? structure or ?+?+? structure and having ? phases distributed uniformly therein at a predetermined proportion to suppress local corrosion and induction of stress corrosion cracks.

Abstract: By enhancing a stress corrosion cracking resistance in a leadless brass alloy, specifically by suppressing a velocity of propagation of corrosion cracks in the brass alloy, a straight line crack peculiar to the leadless brass alloy is suppressed, a probability of cracks coming into contact with ? phases is heightened and local corrosion on the brass surface is prevented to suppress induction of cracks by the local corrosion, thereby providing a leadless brass alloy contributable to enhancement of the stress corrosion cracking resistance. The present invention is directed to an Sn-containing Bi-based, Sn-containing Bi+Sb-based or Sn-containing Bi+Se+Sb-based leadless brass alloy excellent in stress corrosion cracking resistance, having an ?+? structure or ?+?+? structure and having ? phases distributed uniformly therein at a predetermined proportion to suppress local corrosion and induction of stress corrosion cracks.

Abstract: There are provide a nickel elution prevention method for preventing a water-contact instrument made of copper alloy from eluting nickel even when being water-contact with a fluid, such as city water, a protective film formation agent for preventing the elution of nickel and a detergent for preventing the elution of nickel. The water-contact instrument includes valves for city water, feedwater or hot water, pipe joints, strainers, water faucet clasps, pump supplies materials, water meters, water purifiers, water feeders, hot water feeders or other such water-contact instruments each made of copper alloy, such as bronze, brass, etc., plated with a material containing nickel, for example.

Abstract: There are provide a nickel elution prevention method for preventing a water-contact instrument made of copper alloy from eluting nickel even when being water-contact with a fluid, such as city water, a protective film formation agent for preventing the elution of nickel and a detergent for preventing the elution of nickel. The water-contact instrument includes valves for city water, feedwater or hot water, pipe joints, strainers, water faucet clasps, pump supplies materials, water meters, water purifiers, water feeders, hot water feeders or other such water-contact instruments each made of copper alloy, such as bronze, brass, etc., plated with a material containing nickel, for example.

Abstract: A copper-based alloy that has the soundness of alloy enhanced by restraining the concentrated occurrence of microporosities while suppressing the lead content and an ingot and a liquid-contacting part using the alloy are provided. The copper-based alloy has the soundness of alloy improved during the course of solidification of the copper-based alloy by crystallizing an intermetallic compound capable of solidifying at a temperature exceeding a solidus line in dendritic gaps of the alloy, suppressing migration of a solute, thereby allowing dispersion of microporosities, utilizing crystallization of the intermetallic compound as well for effecting dispersed crystallization of a low melting metal or a low melting intermetallic compound capable of solidifying at a temperature falling short of a liquidus line, and relying on the low melting metal or low melting intermetallic compound to enter the microporosities and suppress occurrence of microporosities.

Abstract: By enhancing a stress corrosion cracking resistance in a leadless brass alloy, specifically by suppressing a velocity of propagation of corrosion cracks in the brass alloy, a straight line crack peculiar to the leadless brass alloy is suppressed, a probability of cracks coming into contact with ? phases is heightened and local corrosion on the brass surface is prevented to suppress induction of cracks by the local corrosion, thereby providing a leadless brass alloy contributable to enhancement of the stress corrosion cracking resistance. The present invention is directed to an Sn-containing Bi-based, Sn-containing Bi+Sb-based or Sn-containing Bi+Se+Sb-based leadless brass alloy excellent in stress corrosion cracking resistance, having an ?+? structure or ?+?+? structure and having ? phases distributed uniformly therein at a predetermined proportion to suppress local corrosion and induction of stress corrosion cracks.

Abstract: The object of the present invention is to provide a bronze-based alloy of low lead content, first improved in tensile strength at high temperatures, secondly contributing to the promotion of the environmental conservation including recycling, while avoiding the adverse effect of lead on human bodies by means of reduction of a lead content, and excellent from the standpoints of mass-productivity and manufacturing cost. The alloy includes 2.0 to 6.0 mass % of Sn, 3.0 to 10.0 mass % of Zn, 0.1 to 3.0 mass % of Bi, 0.1 mass %<P?0.6 mass % and the remainder of Cu and unavoidable impurities to improve the tensile strength thereof at high temperatures.

Abstract: There are provide a nickel elution prevention method for preventing a wetted instrument made of copper alloy from eluting nickel even when being wetted with a fluid, such as city water, a protective film formation agent for preventing the elution of nickel and a detergent for preventing the elution of nickel. The wetted instrument includes valves for city water, feedwater or hot water, pipe joints, strainers, water faucet clasps, pump supplies materials, water meters, water purifiers, water feeders, hot water feeders or other such wetted instruments each made of copper alloy, such as bronze, brass, etc., plated with a material containing nickel, for example.

Abstract: A copper-based alloy that has the soundness of alloy enhanced by restraining the concentrated occurrence of microporosities while suppressing the lead content and an ingot and a liquid-contacting part using the alloy are provided. The copper-based alloy has the soundness of alloy improved during the course of solidification of the copper-based alloy by crystallizing an intermetallic compound capable of solidifying at a temperature exceeding a solidus line in dendritic gaps of the alloy, suppressing migration of a solute, thereby allowing dispersion of microporosities, utilizing crystallization of the intermetallic compound as well for effecting dispersed crystallization of a low melting metal or a low melting intermetallic compound capable of solidifying at a temperature falling short of a liquidus line, and relying on the low melting metal or low melting intermetallic compound to enter the microporosities and suppress occurrence of microporosities.