奥氏体化温度对51CrV4钢组织及疲劳性能的影响  

Effect of austenitizing temperature on microstructure and fatigue properties of 51CrV4 steel

作　　者：丁灿灿 曹燕光 杨俊伟[2] 李昭东[2] 曾斌[3] 隋凤利 DING Can-can;CAO Yan-guang;ZENG Bin;YANG Jun-wei;LI Zhao-dong;SUI Feng-li(School of Metallurgical Engineering,Anhui University of Technology,Ma'anshan 243032,Anhui, China;Institute of Structural Steels,Central Iron and Steel Research Institute,Beijing 100081, China;Technical Center,Lianyuan Iron and Steel Co.,Ltd.,Loudi 417009,Hunan,China)

机构地区：[1]安徽工业大学冶金工程学院,安徽马鞍山243032 [2]钢铁研究总院工程用钢研究所,北京100081 [3]湖南华菱涟源钢铁有限公司技术中心,湖南娄底417009

出　　处：《钢铁研究学报》2018年第12期991-997,共7页Journal of Iron and Steel Research

基　　金：国家重点基础研究发展计划资助项目(2015CB654803)

摘　　要：利用拉-拉疲劳试验方法对比研究了51CrV4钢不同奥氏体化温度下试样的疲劳性能,并采用扫描电镜(SEM)对其微观组织变化和疲劳断口进行了分析。结果表明,当奥氏体化温度由850℃升高至900℃后,疲劳强度由840 MPa增加到883 MPa,疲劳断口表面二次裂纹数量增多,且主裂纹扩展路径更曲折,裂纹扩展速率降低。且随着奥氏体化温度的升高,组织中合金渗碳体得到细化,部分碳和合金元素从大尺寸合金渗碳体中回溶到基体中,增加了固溶强化,强度和硬度分别增加约32 MPa和20HV。通过分析发现,合金渗碳体细化及碳和合金元素的回溶是疲劳性能改善的主要因素。Fatigue properties of the 51 CrV4 steel were investigated by comparison at different austenitizing temperature with tension-tension fatigue tests, and the microstructure changes and fatigue fractures were analyzed by scanning electron microscopy(SEM). The results show that the austenitizing temperature increases from 850 ℃ to 900 ℃, the fatigue strength increases from 840 MPa to 883 MPa, the number of secondary cracks on the fatigue fracture surface increases, and the main crack propagation path is more tortuous, and the crack growth rate decreases. The alloy cementite in the microstructure is refined, and some carbon and alloy elements are dissolved back into the matrix from the large-size alloy cementite, which increases the solid solution strengthening, and the strength and hardness increase by about 32 MPa and 20 HV, respectively. Through analysis, it was found that the refinement of large-size alloy cementite and the back-melting of some carbon and alloy elements are main factors to improve the fatigue properties.

关 键 词：奥氏体化温度 显微组织 疲劳性能 51CrV4钢 夹杂物 

分 类 号：TG142.1[一般工业技术—材料科学与工程]