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通过富氩气体保护焊方法,采用直径为1.2 mm的JM-110实芯焊丝对3 mm厚的HC500和HC950汽车用高强钢板进行搭接焊,并对接头金相组织进行了观察,对接头剪切拉伸强度、硬度等力学性能进行了检验。结果表明,焊接热影响区发生了较为严重的软化现象,随着焊接线能量提高,焊接接头剪切拉伸强度先升高后降低,软化区域扩大;当线能量为1.71 k J/cm时,接头性能最优,接头剪切拉伸强度达到770 MPa左右,焊缝区显微组织主要是针状铁素体+先共析铁素体以及少量的马氏体,两种钢的热影响区组织类型基本相似,过热区组织均为板条马氏体+贝氏体,细晶区和不完全正火区主要为马氏体+铁素体,但组织中马氏体和铁素体的含量有较大差别。
The argon-rich gas shielded welding method was used to lap-weld the 3mm-thick HC500 and HC950 automotive high-strength steel with JM-110 solid wire with a diameter of 1.2 mm. The joint microstructure was observed, Cut tensile strength, hardness and other mechanical properties were tested. The results show that the HAZ has a serious softening phenomenon. With the increase of the welding wire energy, the shear tensile strength of welded joints firstly increases and then decreases, and the softened zone expands. When the linear energy is 1.71 kJ / cm, The joint performance is the best, the joint shear tensile strength reaches about 770 MPa, the weld microstructure is mainly acicular ferrite + proeutectoid ferrite and a small amount of martensite, the heat affected zone Tissue types are similar, the overheated zone are lath martensite + bainite, fine grain and not normalizing zone is mainly martensite + ferrite, but the organization of martensite and ferrite There is a big difference in content.