1500 MPa级贝氏体/马氏体复相高强度钢的疲劳特性  

Fatigue Properties of 1500 MPa Bainite/Martensite Dual-Phase High Strength Steel

作　　者：韦东远[1] 顾家琳[1] 方鸿生[1] 白秉哲[1] 

机构地区：[1]清华大学材料科学与工程学院,北京100084

出　　处：《钢铁研究学报》2003年第4期46-50,共5页Journal of Iron and Steel Research

基　　金：国家973新一代钢铁材料重大基础研究资助项目(G1998061513)

摘　　要：对于一种C Si Mn Cr合金,通过900℃奥氏体化20min、空冷及280℃和370℃回火2h,获得了抗拉强度为1500MPa的新型贝氏体 马氏体(B M)复相组织高强度钢。利用疲劳实验研究了B M复相高强度钢的疲劳极限,并采用C T试样测定了疲劳裂纹扩展速率曲线。结果表明,B M复相高强度钢的疲劳极限超过700MPa,疲劳裂纹门槛值约为12 7MPa·m1 2;经370℃回火的B M复相高强度钢疲劳裂纹扩展速率较280℃回火时低;这种钢的疲劳性能较常规调质处理的高强度钢有所改善。The ultimate tensile strength of a novel bainite/martensite dualphase high strength steel (CSiMnCr alloy) is above 1 500 MPa after austenitizing at 900 ℃ for 20 min and then air cooled and tempered for 2 h at 280 ℃ and 370 ℃, respectively. The fatigue limit of the steel was studied by fatigue test. The curve of fatigue crack propagation rate was measured on compacttensile specimens. The results show that the fatigue limit value of this steel exceeds 700 MPa, the fatigue crack threshold value is about 127 MPa·m1/2 and the effect of tempering temperature is small. The fatigue crack propagation rate after tempering at 370 ℃ is lower than that after tempering at 280 ℃. From the experimental results, it is believed that the improved fatigue properties of the steel is related to toughening of high strength steel.

关 键 词：B/M复相 高强度钢 疲劳极限 疲劳裂纹 扩展速率 

分 类 号：TG142.4[一般工业技术—材料科学与工程]