| 摘要 |
A hot worked matrix steel consisting of (in weight-%) 0.60-0.85 C, 0.05-0.5 Si, ≦̸0.5 (Si+Al), 0.1-2.0 Mn, 4.5-5.5 Cr, 1.5-2.6 Mo, ≦̸1.0 W, 1.5-2.6 (Mo+W/2), 0.42-0.65 V, ≦̸0.1 Nb, ≦̸0.1 Ti, ≦̸0.1 Zr, ≦̸2.0 Co, ≦̸2.0 Ni, ≦̸0.003 S, optionally, up to 30 ppm B, balance iron and unavoidable impurities. The steel after hardening and tempering at 520-600° C. (2×2 h) has a hardness of 57-63 HRC and an un-notched impact energy in the transverse direction of 20-100 J. The steel consists of tempered martensite. The steel contains 1.04 vol. % or less of primary precipitated vanadium carbides. The steel is void of primary carbides other than primary precipitated vanadium carbides. |
