焊接电流对M51/RM80异种钢电阻点焊接头力学性能和断裂行为的影响  

Effect of Welding Current on Mechanical Properties and Fracture Behavior of M51/RM80 Dissimilar Steel Resistance Spot Welded Joints

作　　者：陈刚[1] 唐啸天 刘国跃 贾寓真 CHEN Gang;TANG Xiaotian;LIU Guoyue;JIA Yuzhen(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Sawing Engineering Research Center of Hunan Province,Changsha 410200,China;Hunan Taijia New Materials Technology Co.,Ltd.,Changsha 410200,China)

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082 [2]湖南省高速高效双金属锯切工程技术研究中心,湖南长沙410200 [3]湖南省泰嘉新材料科技股份有限公司,湖南长沙410200

出　　处：《热加工工艺》2022年第5期18-22,共5页Hot Working Technology

基　　金：国家自然科学基金项目(51971091);湖南省战略性新兴产业科技攻关类项目(2016GK4018)。

摘　　要：将电阻点焊技术引入到双金属带锯条制备过程中齿材与背材的焊接工序,采用剪切测试研究了焊接电流对M51粉末冶金高速钢和RM80高强度钢异种钢焊接接头强度的影响,并采用金相显微镜和扫描电子显微镜观察了不同焊接电流下焊接接头界面组织及剪切断裂行为。结果表明:随着焊接电流增大,焊接接头强度先升高后降低。焊接电流低于800 A时,接头剪切断裂主要发生在焊缝界面位置;焊接电流高于800 A时,接头剪切断裂主要发生在RM80钢侧热影响区;当电流为800 A时,剪切强度达到最大值,为420.8 MPa。通过拟合界面强度及软化区强度分析了焊接接头失效的规律。Resistance spot welding technology is introduced into the welding process of tooth and back material during the preparation of bimetal band saw blades.The shear test was used to study the effect of welding current on the strength of dissimilar steel welded joints of M51 powder metallurgy high speed steel and RM80 high strength steel.The metallurgical microscope and scanning electron microscope were used to observe the interface microstructure and shear fracture behavior of welded joints under different welding currents.The results show that with the welding current increasing,the strength of the welded joint increases first and then decreases.When the welding current is lower than 800A,the shear fracture of the joint is mainly at the weld interface position.When the welding current is higher than 800A,the joint shear fracture is mainly in the heat affected zone of the RM80 steel side.When the current is 800A,the shear strength reaches the maximum of 420.8 MPa.By fitting the interface strength and the strength of the softened zone,the failure of the welded joint was analyzed.

关 键 词：电阻焊 双金属带锯条 焊接强度 热影响区 

分 类 号：TG453.9[金属学及工艺—焊接]