回火温度对3Cr3Mo3VNb钢力学性能和断口形貌的影响  

Effects of Tempering Temperature on Mechanical Properties and Fracture Morphology of 3Cr3Mo3VNb Steel

作　　者：李飞 张程 张国赏[1,2] 王晓东[1,2] 张玉琦 胡金梦 LI Fei;ZHANG Cheng;ZHANG Guoshang;WANG Xiaodong;ZHANG Yuqi;HU Jinmeng(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471003,China;National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology,Luoyang 471003,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南科技大学金属材料磨损控制与成型技术国家地方联合工程研究中心,河南洛阳471003

出　　处：《热加工工艺》2024年第2期41-46,共6页Hot Working Technology

基　　金：国家重点研发计划资助项目(2020YFB2008400)。

摘　　要：通过控制回火温度,获得了不同力学性能的3Cr3Mo3VNb钢。试验结果表明,在300~680℃回火温度区间内,试验钢的硬度整体呈下降趋势,在500℃回火后出现二次硬化现象,试验钢加速软化发生在600℃以上高温回火;其冲击韧性在300~680℃回火温度区间逐渐增强,650℃以上回火后,冲击韧性快速提升。经过不同温度回火后,3Cr3Mo3VNb钢得到不同的室温组织,其显微组织由回火马氏体转化为回火屈氏体和回火索氏体。碳化物的形态由颗粒状转化成长条状,最后为块状。试验钢的断裂方式为准解理断裂和韧性断裂,准解理断裂发生在300~650℃温度区间,韧性断裂发生在680℃高温回火。试验钢的冲击韧性受显微组织和碳化物的影响较大。3Cr3Mo3VNb steels with different mechanical properties were obtained by controlling tempering temperature.The test results show that,in the tempering temperature range of 300-680℃,the hardness of the test steel shows a downward trend as a whole,the secondary hardening phenomenon occurs when tempering at 500℃,and the accelerated softening of the test steel occurs in high temperature tempering above 600℃.The impact toughness increases gradually in the tempering temperature range of 300-680℃,and increases rapidly after tempering above 650℃.After tempering at different temperatures,different room temperature microstructure for 3Cr3Mo3VNb steel is obtained and its microstructure is transformed from tempered martensite to tempered troostite and tempered sorbite.The morphology of carbide changes from granular to strip,and finally to block.The fracture modes of the test steel are quasi cleavage fracture and ductile fracture.The quasi-cleavage fracture occurs in the temperature range of 300-650℃,and the ductile fracture occurs in the high temperature temper of 680℃.The impact toughness of the test steel is greatly affected by microstructure and carbide.

关 键 词：回火温度 力学性能 断口形貌 二次硬化 

分 类 号：TG161[金属学及工艺—热处理]