烘烤对980MPa先进高强钢RSW接头性能的影响  

Effect of baking on mechanical properties of RSW joints of 980 MPa advanced high strength steel

作　　者：刘立学[1] 孟根巴根[1] 许晓 夏明生[1] 牟永胜 赵光 Liu Lixue;Menggen Bagen;Xu Xiao;Xia Mingsheng;Mou Yongsheng;Zhao Guang(Tangshan Iron&Steel Group Co.,Ltd.,Tangshan 063016,Hebei,China;Linyi Institute of Special Equipment Inspection,Linyi 276000,Shandong,China)

机构地区：[1]唐山钢铁集团有限责任公司,河北唐山063000 [2]临沂市特种设备检验研究院,山东临沂276000

出　　处：《焊接》2024年第1期64-72,共9页Welding & Joining

摘　　要：以DP980-DP980,DP980-QP980和QP980-QP980焊接组合在5√t熔核直径条件下的电阻点焊接头为研究对象,通过170℃保温20 min的烘烤处理,对接头进行拉剪试验、十字拉伸试验、扫描电镜观察及显微硬度测试等,分析了烘烤对980 MPa先进高强钢RSW接头性能的影响。结果表明,烘烤使各组合的抗拉剪峰值载荷进一步提升,接头吸收能量提升均超过10%;在十字拉伸方面,3种组合接头在烘烤后具有相近的能量吸收,对于DP980-QP980和QP980-QP980接头,烘烤后十字拉伸强度分别提升了56%和63%,吸收能量分别提升了27%和67%;3种组合的拉剪失效模式在烘烤前后没有显著变化,而经烘烤后,DP980-QP980的十字拉伸失效模式呈现QP980侧的裂纹扩展路径从熔合线向母材偏移的趋势;烘烤使点焊接头的金相组织呈现一定的回火特性,熔核硬度有一定的降低,但是并不显著。Resistance spot welded joints(RSW joints)of DP980-DP980,DP980-QP980 and QP980-QP980 welding combinations under the condition of 5√t nugget diameters were taken as research object.After being baked at 170℃for 20 minutes,RSW joints were subjected to tensile shear test,cross tensile test,scanning electron microscopy observation,and microhardness testing.Effect of baking on mechanical properties of RSW joints of 980 MPa advanced high strength steel was analyzed.The result showed that baking further increased the peak tensile shear load of each combination,and absorbed energy of RSW joints increased by more than 10%.In terms of cross tensile,RSW joints of the three combinations have similar energy absorption after baking.For DP980-QP980 and QP980-QP980 RSW joints,cross tensile strength after baking increased by 56%and 63%,and absorbed energy increased by 27%and 67%,respectively.Tensile and shear failure modes of the three combinations did not show significant changes before and after baking,while cross tensile failure mode of DP980-QP980 after baking showed a trend of crack propagation path shifting from fusion line to base metal on the QP980 side.Baking resulted in a certain tempering characteristic of metallographic structure of RSW joints and a certain decrease in hardness of nugget,but it was not significant.

关 键 词：烘烤 电阻点焊 先进高强钢 性能 

分 类 号：TG453[金属学及工艺—焊接]