激光熔覆EA4T钢热影响区组织转变及力学性能研究  

Study on Microstructure Transformation and Mechanical Properties of Heat Affected Zone of Laser Cladding EA4T Steel

作　　者：罗锋 陈文静[2] 罗照洋 吴谊彬 LUO Feng;CHENWenjing;LUO Zhaoyang;WU Yibin(China Nuclear Industry No.23 Construction Co.,Ltd.,Beijing 101300,China;School of Materials Science and Engineering,Xihua University,Chengdu 610039,China)

机构地区：[1]中国核工业二三建设有限公司,北京顺义101300 [2]西华大学材料科学与工程学院,四川成都610039

出　　处：《电焊机》2022年第8期72-80,共9页Electric Welding Machine

摘　　要：以EA4T钢车轴为研究对象,利用铁基粉末Fe314对EA4T车轴进行激光熔覆再制造试验,采用光学显微镜和扫描电镜分析热影响区的相组成,讨论了激光熔覆EA4T钢热影响区微观组织转变,并测试了界面区域合金元素分布和界面微观力学性能。研究结果表明:激光熔覆EA4T钢热影响区组织主要为板条马氏体组织,在接近界面区域奥氏体匀质化和碳化物的溶解过程很不充分,晶粒粗大;在热影响区的细晶区,其微观组织主要为马氏体和少量索氏体组织,且呈一定的方向性;另外在激光熔覆工艺条件下,EA4T钢热影响区所经历的最高温度对组织演变及力学性能起决定性作用,在结合区位置合金元素出现突变,晶粒取向明显,热影响区的抗剪切强度增加,但压入率降低。Laser cladding of EA4T steel,the phase composition of the heat affected zone was analysed by optical microscopy and scanning electron microscopy. The effect of laser cladding on the microstructure transformation of the heat affected zone of EA4T steel was discussed. The distribution of alloying elements and the micromechanical properties of the interface were measured. The results showed that the microstructure of the heat affected zone(HAZ) of laser cladding EA4T steel was mainly lath martensite. Near the interface area, the homogenization of austenite and the dissolution of carbides were not sufficient, and the grains were coarse. In addition, under laser cladding process conditions, the highest temperature experienced in the heat affected zone of EA4T steel played a decisive role in organizational evolution and mechanical properties. With abrupt changes in alloying elements at the location of the bonding zone, significant grain orientation, shear strength in the heat affected zone increased, but indentation rate reduced.

关 键 词：激光熔覆 微观组织 界面特性 晶粒取向 

分 类 号：TG457[金属学及工艺—焊接]