汽车用1000 MPa级DP钢电阻点焊接头组织性能分析  

Reserch on Microstructure and Properties of Resistance Spot Welded Joints of 1000 MPa DP Steel for Automobile

作　　者：贾坤宁[1] 杨海峰 JIA Kun-ning(School of Mechanical&Electrical Engineering,Changchun Institute of Technology,Changchun 130012,China)

机构地区：[1]长春工程学院机电工程学院,长春130012 [2]哈尔滨工业大学(威海)山东省特种焊接技术重点实验室,山东威海264209

出　　处：《长春工程学院学报（自然科学版）》2022年第3期38-41,共4页Journal of Changchun Institute of Technology：Natural Sciences Edition

基　　金：吉林省教育厅“十三五”科学技术项目(JJKH20200613KJ)。

摘　　要：以1 mm厚的DP1000钢板为研究对象,对其进行不同工艺条件下的电阻点焊,并对焊接接头的显微硬度、拉伸结果、断口形态及显微组织进行分析。结果表明:DP1000钢电阻点焊接头的熔核区微观组织为粗大的板条状马氏体,呈柱状晶形态,热影响区的微观组织主要为板条状马氏体和奥氏体;点焊接头的强度会随着电流、电极压力的增加先增加后下降,随着焊接时间的增加而增加;拉剪实验的断裂位置为焊点和热影响区,热影响区断口存在大量的韧窝和少量准解理台阶,属于混合型断裂;接头显微硬度熔核最高,其次为热影响区,母材最低。The DP1000 steel of 1 mm thick plate is studied in this paper,the test steel was welded with different welding parameter,and the microhardness,tensile results,fracture morphology and microstructure of the welded joint were studied.The results show that the microstructure of the nugget zone is consist of lath martensite with columnar crystal morphology,and the heat-affected microstructure is consist of martensite and austenite.The tensile-shear property of the joint firstly increases and then decreases with the increase of current and electrode pressure,and increases with the increase of welding time.The fracture position of the sample is the nugget and the heat-affected zone.There are a lot of dimples and a few quasi-cleavage steps on the fracture surface of the heat affected zonethe fracture model is mixed fracture.The microhardness in the nugget is the highest,followed is the heat-affected zone,and the base material is the lowest.

关 键 词：DP1000钢板 电阻点焊 力学性能 显微组织 

分 类 号：TG453[金属学及工艺—焊接]