| 摘要 |
PCT No. PCT/JP95/00276 Sec. 371 Date Aug. 23, 1996 Sec. 102(e) Date Aug. 23, 1996 PCT Filed Feb. 24, 1995 PCT Pub. No. WO95/23241 PCT Pub. Date Aug. 31, 1995A fine graphite uniform dispersion steel material excellent in cold workability, cuttability and hardenability, which has graphite finely and uniformly dispersed therein, and a production method for producing the same. The steel contains at least 0.30 to 1.0% of C, 0.4 to 1.3% of Si, 0.3 to 1.0% of Mn, 0.0003 to 0.006% of B, 0.002 to 0.010% of N and 0.05 to 0.20% of Mo as the basic components and contains graphite having a mean particle diameter of not more than 4.0 mu m and a number of particles per unit and of at least 3,000 per mm2. The production method includes at least the steps of cooling the steel having these components at a cooling start temperature of not less than an Arl point, a cooling end temperature of not more than an Ms point and a mean cooling rate of 5 DEG to 100 DEG C./s. |
