渗碳工艺对18CrNiMo7-6合金钢缺口件疲劳性能的影响  

Effect of Carburizing on Fatigue Properties of Notched 18CrNiMo7-6 Alloy Steel

作　　者：秦盛伟 邸黎寅 王连翔 张承昊 QIN Shengwei;DI Liyin;WANG Lianxiang;ZHANG Chenghao(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学机械与动力工程学院,郑州450001

出　　处：《材料导报》2024年第2期200-206,共7页Materials Reports

基　　金：国家自然科学基金(52001281;U1804254);河南省科技攻关项目(192102210012)。

摘　　要：为分析渗碳工艺对18CrNiMo7-6缺口构件疲劳性能的影响,对应力集中系数Kt=1.86的缺口试样进行渗碳热处理并测定其旋转弯曲疲劳性能,同时对试样表层组织、硬度以及应力场进行了表征。结果表明,渗碳热处理可以明显提升试样表面硬度并引入残余压应力,并且可以显著提升缺口试样的疲劳性能,相较于未渗碳试样疲劳极限提升超过100%;随着有效硬化层深度的增加,缺口试样的疲劳极限均呈现先增后减的趋势。未渗碳试样和渗碳试样的疲劳源均在缺口根部表面处,且均为多源断裂。疲劳过程中渗碳试样表面残余奥氏体在循环应力作用下诱导马氏体相变,其转变量存在一个临界值。In order to analyze the effect of carburizing process on the fatigue properties of the 18CrNiMo7-6 notched specimens,the notched specimens with stress concentration factor Kt=1.86 were carburized and then these rotating bending fatigue properties were measured.The microstructure,hardness and stress field of the specimens were characterized.The results show that carburizing heat treatment can significantly promote the surface hardness of the sample and introduce residual compressive stress.The fatigue limit of the notched samples is increased more than 100%compared with the uncarburized samples.With the increase of the depth of effective hardening layer,the fatigue limit of notched specimens increases first and then decreases.The fatigue sources of the uncarburized and carburized specimens are at the surface of notch root,and both of them are multi-source fracture.During fatigue,martensitic transformation of the retained austenite takes place on the surface of carburized specimen,and there is a critical value for its transformation.

关 键 词：18CrNiMo7-6合金钢 应力集中 渗碳热处理工艺 高周疲劳性能 

分 类 号：TG156[金属学及工艺—热处理]