衬板用超高强度空冷贝-马复相铸钢的热处理工艺优化

Optimization of heat treatment process of ultra high strength air cooling bainite-martensite multiphase cast steel for crusher liner

利用正交试验、力学性能测试及组织观察对自行设计的圆锥破碎机衬板用超高强度空冷贝-马复相铸钢的热处理工艺进行了优化。结果表明:回火温度对试验钢的强度影响最大,保温时间对试验钢的无口冲击吸收能量影响最大。试验钢的最佳热处理工艺为:900℃×1.5 h空冷+300℃×2 h回火。最佳热处理工艺下,试验钢的组织为:51.7%下贝氏体+43.4%马氏体+4.9%残留奥氏体,具有较优的综合力学性能,抗拉强度1683 MPa,规定非比例延伸强度1490 MPa、硬度51.3 HRC,无口冲击吸收能量151.4 J。

Heat treatment process of an ultra high strength air cooling bainite-martensite multiphase cast steel for crusher liner was optimized by orthogonal test,mechanical test and microstructure observation. The results show that the tempering temperature has the greatest influence on the strength of the tested steel,and the holding time has the greatest influence on the impact absorbed energy. The best heat treatment process of the steel is： 900 ℃ × 1. 5 h air cooling ＋ 300 ℃ × 2 h tempering. Under the optimum heat treatment process,the microstructure of the steel is as follows： 51. 7% lower bainite ＋ 43. 4% martensite ＋ 4. 9% retained austenite,which has excellent mechanical properties：tensile strength 1683 MPa,specified non proportional extension strength 1490 MPa,hardness of 51. 3 HRC,and the no opening Charpy impact absorbed energy 151. 4 J.