LEAD-FREE BRASS ALLOY WITH EXCELLENT RESISTANCE TO STRESS CORROSION CRACKING

摘要

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 ³ 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 ± + ³ structure or ± + ² + ³ structure and having ³ phases distributed uniformly therein at a predetermined proportion to suppress local corrosion and induction of stress corrosion cracks.