LEAD-FREE FREE CUTTING BRASS EXCELLENT IN DEZINCIFICATION CORROSION RESISTANCE AND ITS PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide lead-free free cutting brass provided with excellent dezincification corrosion resistance and machinability and having good hot workability and cold workability and to provide its production method. SOLUTION: This brass has a composition containing 59.0 to 62.0% Cu, 0.3 to 4.0% Bi, 0.02 to 0.07% P and <=0.30% Fe, and the balance Zn with inevitable impurities and has structure composed of the two phases of anαphase and aβphase, and in which theβphase is also parted by theαphase. The brass is produced by subjecting the ingot of an alloy having the above composition to extrusion or extrusion and streching and thereafter annealing the same at 350 to 550 deg.C.