摘要
采用单脉冲电阻点焊连接技术,研究不同的焊接电流和焊接时间条件下不等厚22MnB5/DP590点焊接头截面特征和拉伸性能,分析点焊接头显微硬度的变化规律。结果表明:焊接电流对母材焊透率和熔核厚度的影响不大。随焊接电流的增加,熔核向较厚DP590侧方向偏移,接头熔核直径和拉剪力增加。与焊接电流相比,焊接时间的增加对接头压痕率和熔核偏移量的影响严重;随焊接时间的增加,母材的焊透率和熔核厚度减小,焊接时间为1000 ms时熔核直径减小,而拉剪力一直增加。点焊接头的显微硬度值由高到低分别为22MnB5侧热影响区→熔核区→DP590侧热影响区。在拉剪力作用下,接头拉伸断裂方式有界面断裂、部分界面断裂和熔核拔出断裂。并由此得出结论:在电极压力为3.8 kN的条件下,不等厚DP590/22MnB5的最佳点焊工艺为焊接电流为8.5 kA,焊接时间为160 ms。
In this paper,the single pulse resistance spot welding technology was used to study the section characteristics and tensile properties of 22MnB5/DP590 spot welding joints with varying thickness section under different welding current and welding time,and the variation of microhardness of spot welding joints was analyzed.The results show that the welding current has little effect on the penetration and core thickness of the base metal.With the increase of welding current,the weld core moves towards the thicker DP590 side,and both weld diameter and tensile shear of the joint increase.Compared with the welding current,prolonging welding time has significant effect on the indentation rate and core offset of the joint.With the increase of welding time,the penetration of the base metal and the thickness of the molten core decrease.The diameter of the molten core decreases when the welding time is1000 ms,but the tensile shear keeps increasing.The microhardness values of spot welded joints from high to low are as follows:22MnB5 side heat affected zone→molten core zone→DP590 side heat affected zone.Under the action of tensile shear,the joint tensile fracture modes include interface fracture,partial interface fracture and core pulling out fracture.It is concluded that given 3.8 kN of welding force the optimum welding conditions for varying section of DP590/22MnB5 are 8.5 kA of welding current and 160 ms of welding time.
作者
于永梅
李治国
娄国栋
荆毅
Yu Yongmei;Li Zhiguo;Lou Guodong;Jing Yi(College of Mechanical and Power Engineering,Shenyang University of Chemical Technology,Shenyang 110142,Liaoning,China;State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,Liaoning,China)
出处
《钢铁钒钛》
CAS
北大核心
2024年第4期181-188,共8页
Iron Steel Vanadium Titanium
基金
国家自然科学基金面上项目(51974085)。
作者简介
于永梅,1974年出生,女,汉族,辽宁沈阳人,博士,副教授,研究方向:金属材料组织与性能研究,E-mail:3234547867@qq.com。
