PURPOSE: To obtain a free cutting austenite stainless steel with improved press formability suitable for use as a material for a watchcase, etc. by combinedly adding a restricted amount of Ni and Cu to an austenite stainless steel having a specified composition.
CONSTITUTION: This austenite stainless steel consists of, by weight, ≤0.1% C, ≤2% Si, ≤2% Mn, 15W20% Cr, 12W18% Ni, 1W6% Cu, ≤2% Mo, ≤0.2% N, 0.05W0.20% S and the balance Fe with inevitable impurities while satisfying Ni+Cu=13W24%. By the synergistic effect of Ni and Cu added by such a restricted total amount, superior press formability is provided. The steel maintains machinability equal to that of an ordinary free cutting stainless steel. When this steel is applied to a watchcase, etc., the number of repetitions of pressing and that of softening are considerably reduced, resulting in a lower cost.
TAKAHASHI ICHIROU
SAKAE TOYOYUKI
KOTAKI TAKAO
HIRAHARA KAZUO
