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 dualphase high strength steel (CSiMnCr 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 compacttensile specimens. The results show that the fatigue limit value of this steel exceeds 700 MPa, the fatigue crack threshold value is about 127 MPa·m1/2 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.
出处
《钢铁研究学报》
CAS
CSCD
北大核心
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)
关键词
B/M复相
高强度钢
疲劳极限
疲劳裂纹
扩展速率
bainite/martensite dual-phase
high strength steel
fatigue limit
fatigue crack
propagation rate
