摘要 |
<P>PROBLEM TO BE SOLVED: To provide a steel material excellent in productivity without performing heat treatment over a long time, that is, annealing over a long time for graphitization, and excellent in machinability and a damping property. <P>SOLUTION: This steel material contains, by mass%, 0.3-1.2% of C, 2.0-3.0% of Si, >0.05% and ≤0.5% of Mn, 0.2-1.0% of Al, ≤0.02% of P, 0.007-0.2% of S, 0.0015-0.030% of N and ≤0.003% of O, wherein the content of Si and Mn is in a range satisfying the following expression: ä5≤Si/Mn}; the residue has a component composition comprising Fe and unavoidable impurities; a steel structure includes a ferrite structure and graphite; and a graphitization degree is >80%. <P>COPYRIGHT: (C)2012,JPO&INPIT |