回火工艺对Cr-Ni-Mo-V高强钢组织和力学性能的影响  

Effect of tempering process on microstructure and mechanical properties of Cr-Ni-Mo-V high strength steel

作　　者：王小龙 王毛球[2] 孟彬[1] 时捷[2] 徐乐[2] 孙挺[2] 

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650000 [2]钢铁研究总院特殊钢研究所,北京100081

出　　处：《金属热处理》2017年第12期135-140,共6页Heat Treatment of Metals

摘　　要：利用力学性能测试、金相观察、TEM、SEM和XRD等分析手段,研究了回火温度对40CrNi3MoV和50CrNi5MoV钢组织与力学性能的影响。结果表明,40CrNi3MoV钢和50CrNi5MoV钢回火后的组织具有板条马氏体特征,在板条马氏体的边界分布着高密度位错。试验钢在500~650℃范围内回火时,随着回火温度的增加,碳化物析出并长大;硬度、强度呈下降趋势;而冲击吸收能量、伸长率、断面收缩率呈上升的趋势。由于C、Mo和Ni含量的增加,在500~550℃范围内回火后,50CrNi5MoV钢的屈服强度能够达到1400MPa级,比40CrNi3MoV钢高170MPa左右,且塑韧性较好。Influence of tempering temperature on mierostructure and mechanical properties of 40CrNi3MoV and 50CrNi5MoV steels were studied by means of mechanical testing, optical microscopy, TEM, SEM and XRD. The results show that the microstructure of 40CrNi3MoV steel and 50CrNi5MoV steel is lath martensite after tempering, and high density dislocation is distributed at the boundary of lath martensite. When tempered between 500-650 ℃, as the increasing of the tempering temperature, the carbides gradually precipitate and grow up, the hardness and tensile strength decrease, but the impact absorbed energy, toughness and ductility increase. Because of the content of C, Ni and Mo is increased, the yield strength of 50CrNi5MoV can reach 1400 MPa, which is higher than that of 40CrNi3MoV steel by 170 MPa when tempered between 500-560 ℃. Meantime, the plastic toughness of the former is better.

关 键 词：40CrNi3MoV钢 50CrNi5MoV钢 回火温度 组织 力学性能 

分 类 号：TG156.4[金属学及工艺—热处理]