| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive, free-cutting ferritic stainless steel that is free of highly toxic heavy metals such as Pb, is excellent in productivity and is excellent in surface accuracy and tool wear resistance in cutting. <P>SOLUTION: The free-cutting ferritic stainless steel contains, by mass%, ≤0.030% C, ≤1.0% Si, ≤2.0% Mn, 0.02-0.10% P, 0.15-0.50% S, 15.0-20.0% Cr, ≤0.030% N, 1.0-2.5% Cu and at least one chosen from 0.03-0.50% Sn, 0.02-0.20% Ag and 0.02-0.50% Zn, and includes a secondary phase composed of essentially Cu and at least one chosen from Sn, Ag and Zn in an amount of ≥2 mass%. In the secondary phase, ones with a grain size of ≥0.01 μm are dispersed in a matrix at an area ratio of ≥0.2% in a cross-sectional structure of the steel and a Vickers hardness is ≥160 Hv. <P>COPYRIGHT: (C)2012,JPO&INPIT |
