Low carbon sulfur free-cutting steel with excellent machinability

摘要

PROBLEM TO BE SOLVED: To provide low-carbon sulfur free-cutting steel which has superior machinability (finished surface roughness, in particular) despite its Pb-free state and can be manufactured with high productivity by a continuous casting process.;SOLUTION: The low-carbon sulfur free-cutting steel has a composition containing, (by mass, the same applies to the following) 0.02 to 0.15% C, ≤0.004% (not including 0%) Si, 0.6 to 3% Mn, 0.02 to 0.2% P, 0.2 to 1% S, ≤0.005% (not including 0%) Al and 0.002 to 0.03% N. Further, the average O concentration in MnS in the steel is ≥0.4%.;COPYRIGHT: (C)2007,JPO&INPIT