Abstract: Martensite transformation and s- carbide precipitation in the steel DT300 -0.33C,1.78Si,0.76Mn, 5.78Ni,1. 10Cr,0.65Mo,0. 12V oil quenched at 840~960 ℃ and effect of quenching temperature on mechanical properties of 300 ℃ tempered steel have been tested and analyzed. Results showed that complete lath martensite and excellent strength-toughness of steel DT300 were obtained by 860~920 ℃1 h oil cooling + 300 ℃ 2 h tempering. The mechanical properties of heat-treated steel were Rm 1860 MPa, Rp_0.21500 MPa,A 12% and A_ku2 58 J.

摘要： 试验和分析了840-960℃油淬的DT300钢(％:0．33C、1．78Si、0．76Mn、5．78Ni、1．10Cr、0．65Mo、0．12V)的马氏体转变和ε-碳化物的析出以及淬火温度对300℃回火后钢的机械性能的影响。结果表明,DT300钢经860-920℃1 h油淬+300℃2 h回火可获得较完全的板条马氏体和优良的强韧性(Rm 1 860 MPa, Rp_0.2 1 500 MPa, A 12％, A_ku2 58 J) 。