摘要
采用电弧焊工艺,选用直径φ3.2 mm的D628焊条在Q345钢表面制备三层堆焊复合金属。通过光学显微镜、SEM扫描电镜、显微硬度计和冲击测试等方法分析堆焊金属的显微组织及性能。结果表明,堆焊层组织主要为莱氏体基体上分布着板条状渗碳体和珠光体,热影响区组织均匀细小。随着堆焊层数的增加,平均硬度值从628.34 HV增加到677.62 HV,且堆焊层第三层与第二层硬度接近,平均值都在650 HV以上,主要原因是随着层数的增加,基体对熔敷金属的稀释作用减弱,堆焊层组织中碳化物的比值增高。对试样进行冲击断口分析发现,从基板到堆焊层,断裂形式由韧性断裂向准解理断裂转变。
Three-layer deposited metal is prepared on Q345 steel by arc welding withφ3.2 mm electrode D628.Microstructure and properties of deposited metals are analyzed by using optical microscopy,scanning electron microscopy(SEM),microhardness tester and impact test.The results show that the microstructure of surfacing layer is mainly composed of cementite lamellae and pearlite on ledeburite matrix,the microstructure of heat affected zone is uniform and fine.As the number of surfacing layers increases,the average hardness value improves from 628.34 HV to 677.62 HV,the hardness of the third layer of surfacing layer is closed to that of second layer,and the average value is above 650 HV.The main reason is as the number of layers increases,the dilution effect of matrix on deposited metal weakens and the ratio of carbides in surfacing layer increases.The impact fracture analysis shows that the fracture mode changes from ductile fracture to quasi-cleavage fracture from the substrate to surfacing layer.
作者
江山
姚宗湘
郑靖上
高敏智
田佳俊
谢清清
张中文
左存果
JIANG Shan;YAO Zongxiang;ZHENG Jingshang;GAO Minzhi;TIAN Jiajun;XIE Qingqing;ZHANG Zhongwen;ZUO Cunguo(School of Metallurgy and Materials Engineering,Chongqing University of Science and Technology,Chongqing 401331,China)
出处
《电焊机》
2019年第11期35-39,共5页
Electric Welding Machine
基金
国家自然科学基金面上项目(51674056)
重庆市教委项目(KJ1713344)
材料腐蚀与防护四川省重点实验室开放课题(2016CL15)
重庆科技学院科研启动基金(CK2016Z08)
重庆科技学院研究生科技创新项目(YKJCX1820203)
关键词
焊条
堆焊
断口形貌
微观组织
显微硬度
electrode
surfacing welding
fracture morphology
microstructure
microhardness
