FREE CUTTING STEEL EXCELLENT IN TOUGHNESS IN HORIZONTAL DIRECTION

摘要

PROBLEM TO BE SOLVED: To provide a free cutting steel excellent in toughness in a horizontal direction as well as in machinability. ;SOLUTION: This steel has an alloy composition consisting of, by weight, 0.25-0.65% C, 0.05-0.50% Si, 0.60-1.60% Mn, 0.02-0.10% Bi, 0.010-0.075% S, further one or ≥2 kinds selected from 0.15-0.60% Cr, 0.0005-0.0030% Ca, and 0.003-0.020% Te, and the balance essentially Fe and containing, if necessary, 0.05-0.35% V. Moreover, the sum of the lengths of inclusions having ≥10 μm length in 1 mm² longitudinal section in a hot rolled state is regulated to ≤1.0 mm.;COPYRIGHT: (C)1998,JPO