| 摘要 |
PROBLEM TO BE SOLVED: To provide a martensitic stainless free-cutting steel which has excellent forgeability by the control of inclusions without using heavy metals (Pb, Bi, Se, Te) exerting adverse influence on the environment, thus to improve the yield of component working which has been performed only by cutting heretofore by the combination with forging. SOLUTION: The ferritic stainless free-cutting steel wire rod having excellent forgeability is composed of a steel containing, by mass,≤0.120% C, 0.1 to 2.0% Si, 0.1 to 3.0% Mn,≤0.05% P, 0.01 to 0.20% S, 11.0 to 30.0% Cr,≤0.250% N, 0.002 to 0.010% Al, 0.001 to 0.010% Ca, 0.001 to 0.025% O, and the balance Fe with inevitable impurities, and satisfying the conditions of, by mass ratio, 0.25≤Ca/Al≤2.50 and 0.10≤C/O≤0.30 to form composite inclusions between CaO-SiO<SB>2</SB>-Al<SB>2</SB>O<SB>3</SB>based oxides having a low softening point and (Mn, Cr)S sulfides. COPYRIGHT: (C)2011,JPO&INPIT
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