20MnCr5钢齿轮表面渗碳层的显微组织  

Microstructure of Carburized Layer on Surface of 20MnCr5 Steel Gear

作　　者：王强[1] 赵四新[1] 高加强[1] WANG Qiang;ZHAO Sixin;GAO Jiaqiang(Research Institute of Baoshan Iron and Steel Co.,Ltd.,Shanghai 201999,China)

机构地区：[1]宝山钢铁股份有限公司中央研究院,上海201999

出　　处：《机械工程材料》2023年第9期106-110,共5页Materials For Mechanical Engineering

摘　　要：在930℃下对20MnCr5钢齿轮进行常规真空渗碳热处理,利用光学显微镜、扫描电镜、透射电镜、电子探针和显微硬度计等研究了渗碳层的显微组织、元素分布和显微硬度。结果表明:渗碳层表层组织由高碳针状马氏体与残余奥氏体组成,随距表面距离增大,针状马氏体向板条马氏体转变;渗碳层中还析出了条状富铬碳化物和球状富锰碳化物,碳化物呈弥散分布;渗碳层表面硬度为860 HV,远高于基体,随距表面距离增大,渗碳层硬度下降。20MnCr5 steel gear was subjected to conventional vacuum carburizing heat treatment at 930 ℃.The microstructure,element distribution and microhardness of the carburized layer were studied by optical microscope,scanning electron microscope,transmission electron microscope,electron probe and microhardness tester.The results show that the microstructure of the carburized layer surface layer consisted of high-carbon acicular martensite and residual austenite.With increasing the distance from the surface,the acicular martensite changed to lath martensite.Strip-like chromium-rich carbides and spherical manganese-rich carbides were also precipitated in the carburized layer,and the carbides were dispersed.The surface hardness of the carburized layer was 860 HV,which was much higher than that of the substrate.With increasing the distance from the surface,the hardness of the carburized layer decreased.

关 键 词：20MnCr5齿轮钢 渗碳层 显微组织 元素偏析 

分 类 号：TG156.8[金属学及工艺—热处理]