| 摘要 |
Provided is a lead-containing free-machining steel having excellent machinability. This lead-containing free-machining steel contains, in terms of mass%, 0.005-0.2% C, 0.3-2.0% Mn, 0.005-0.2% P, 0.01-0.7% S, 0.03-0.5% Pb, 0.004-0.02% N, and 0.003-0.03% O, with the remainder comprising Fe and impurities. The steel contains Pb inclusions (40) having a diameter of 0.01-0.5 μm in terms of equivalent-circle diameter, the number of the inclusions being 10,000 per mm2 or larger. |
