40Cr钢TD盐浴渗钒制备VC渗层的组织形貌  

Microstructure of VC layer prepared by TD salt-bath vanadizing on 40Cr steel surface

作　　者：雷丰荣 李晖[1,2] Lei Fengrong;Li Hui(College of Materials Science and Engineering,Chongqing University of Technology,Chongqing 400054,China;Chongqing Special Welding Materials and Technology Efficient Engineering Research Center,Chongqing 400054,China)

机构地区：[1]重庆理工大学材料科学与工程学院,重庆400054 [2]重庆市特种焊接材料与技术高效工程研究中心,重庆400054

出　　处：《金属热处理》2020年第7期177-182,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(51575073,51275548);国家国际合作专项(2015DFR70480);重庆市科委资助项目(cstc2014gjhz70003)。

摘　　要：为了延长齿轮钢使用寿命,采用热扩散法盐浴渗钒在40Cr钢表面制备VC渗层,并测得了900~1050℃盐浴渗钒6 h的渗层厚度,利用光学显微镜和扫描电镜(SEM)、X射线衍射仪(XRD)对VC渗层的组织形貌、物相成分进行了分析,同时对渗层硬度进行了测试。结果发现,40Cr钢表面形成了5~50μm厚的渗层组织,且不同的处理温度造成了不同程度的渗层组织迁移,渗层物相主要由VC和少量α-Fe相组成,同时VC晶粒生长具有VC(111)和VC(200)两个择优取向,且随处理温度升高,择优取向减弱,而渗层对基体表面硬度均有不同程度地提高。In order to prolong the service life of gear steel,40Cr steel was selected as substrate material to prepare the VC(vanadium carbide)vanadizing layer by TD(thermal diffusion)salt-bath vanadizing.The thickness of the VC layers formed by vanadizing in salt-bath at 900-1050℃for 6 h was measured,and the microstructure,phases and hardness of the VC vanadizing layers were analyzed by metallographic microscope,scanning electron microscope,X-ray diffraction and Vickers indenter.The results show that the thickness of the VC layers on 40Cr surface is 5-50μm,and the treatment temperature difference causes migration of the vanadizing layer microstructure in different degrees.The vanadizing layers are mainly composed of VC phase and a small amount ofα-Fe phase,and the VC grain growth has two preferential orientations of VC(111)and VC(200).The preferential orientations are weakened with the increase of treatment temperature,and the surface hardness of the substrate is improved in different degrees by the vanadizing layers.

关 键 词：40CR钢 TD盐浴渗钒 VC渗层 组织 物相 

分 类 号：TG161[金属学及工艺—热处理]