回火温度对960MPa级工程机械用钢组织与力学性能的影响

Effects of Tempering Temperature on Microstructure and Mechanical Properties of 960 MPa Grade Steel for Engineering Machinery

对热轧后的Q960工程机械用钢进行了910℃保温20min的淬火和不同温度相同时间(40 min)的回火。研究了回火温度对组织和力学性能的影响。结果表明:钢淬火后的组织转变为板条马氏体,当回火温度为600℃时,钢的组织形成了回火索氏体;当回火温度为500℃时,试验钢具有优良的性能,即,R_(p0.2)=990 MPa,R_m=1086 MPa,A=17.8%,-40℃冲击功KV_2=68 J,满足GB/T16270-2009的要求。

Q960 steel for engineering machinery after hot rolling was subjected to quenching at 910 ℃ for 20 mln and tempering at different temperatures for the same time （40 rain）. The effects of tempering temperature on microsttucttLre and mechanical properties were investigated. The results show that the microstructure of the steel after quenching is transformed into the lath martensite. When the tempering temperature is 600 ℃, the microstructure of the steel forms tempered sorbite. When the tempering temperature is 500 ℃, the test steel has excellent properties, namely, Rp0.2=990 MPa, Rm=1086 MPa, A = 17.8% ,-40℃ CKV2=68 J, which meets the requirements of GBFF16270-2009.