不同焊接方法下1MnCrMoNi与Q235异种钢焊接接头的组织和性能研究

Microstructure and Properties of Welded Joint of 1MnCrMoNi and Q235 Dissmilar Steels under Different Welding Methods

采用手工电弧焊(SMAW)和钨极氩弧焊(GTAW),将海洋工程用1MnCrMoNi合金钢与Q235钢进行焊接,研究焊接接头的显微组织、熔合区界面合金元素分布及力学性能。结果表明,GTAW接头Q235热影响区的表层因过热出现魏氏组织,两种接头1MnCrMoNi热影响区粗晶区均有板条马氏体出现,但GTAW接头板条马氏体数量明显较多;GTAW接头1MnCrMoNi侧熔合区界面C、Mo元素严重偏聚;GTAW接头1MnCrMoNi热影响区和焊缝显微硬度高于SMAW接头的,两种接头拉伸性能均与强度较低的Q235母材持平,断裂位置在Q235母材,室温下SMAW接头各区域冲击韧性明显优于GTAW接头的。

1MnCrMoNi alloy steel for offshore engineering and Q235 steel were welded with manual arc welding(SMAW) and tungsten argon arc welding(GTAW), and the microstructure of welded joints, alloy element distribution at the fusion zone interface and mechanical properties were studied. The results show that the surface of the Q235-HAZ of the GTAW joint is overheated and the Widmanstatten structure appears, and the lath martensite appears in the 1MnCrMoNi-CGHAZ of both joints, but the number of the lath martensite of GTAW joints is significantly larger;C and Mo elements are severely segregated in the interface of the 1MnCrMoNi side fusion zone of the GTAW joint;the microhardness of 1MnCrMoNi-HAZ and weld of the GTAW joint are higher than that of the SMAW joint, the tensile properties of both joints are equal to the lower strength Q235 base metal, the fracture position is Q235 base metal, the impact toughness of SMAW joints is obviously better than that of GTAW joints at the room temperature.