CAJ | 학술논문

采用熔化极惰性气体保护电弧焊方法(MIG)实现镁合金和低碳钢的连接，并研究焊接热循环特点和镁?钢对接接头的显微组织及力学性能。研究结果表明，在焊接过程中，接头的温度场分布是不均匀的。镁合金焊缝金属为细小的等轴晶结构。在镁/钢界面存在主要由AlFe、AlFe3和Mg(Fe,Al)2O4相组成的过渡层，这一过渡层是镁?钢接头的最薄弱环节。焊接线能量和焊缝Al含量对镁?钢接头的抗拉强度具有明显的影响。焊接线能量由1680 J/cm增至2093 J/cm，接头强度明显增加，这主要归因于镁/钢界面反应。增加焊缝Al含量至6.20%，镁?钢接头强度可达192 MPa，为AZ31镁合金母材强度的80%。因此，选择合适的焊接线能量和焊缝Al含量有利于改善镁?钢接头的抗拉强度。
채용용화겁타성기체보호전호한방법(MIG)실현미합금화저탄강적련접，병연구한접열순배특점화미?강대접접두적현미조직급역학성능。연구결과표명，재한접과정중，접두적온도장분포시불균균적。미합금한봉금속위세소적등축정결구。재미/강계면존재주요유AlFe、AlFe3화Mg(Fe,Al)2O4상조성적과도층，저일과도층시미?강접두적최박약배절。한접선능량화한봉Al함량대미?강접두적항랍강도구유명현적영향。한접선능량유1680 J/cm증지2093 J/cm，접두강도명현증가，저주요귀인우미/강계면반응。증가한봉Al함량지6.20%，미?강접두강도가체192 MPa，위AZ31미합금모재강도적80%。인차，선택합괄적한접선능량화한봉Al함량유리우개선미?강접두적항랍강도。
The joining of Mg alloy to steel was realized by metal inert-gas arc welding, and the weld thermal cycle characteristics and Mg?steel joints were investigated. The results show that the temperature distribution in the joints is uneven. Mg alloy welds present a fine equiaxed grain structure. There exists a transition layer consisting mainly of AlFe, AlFe3 and Mg(Fe, Al)2O4 phases at Mg/steel interface, and it is the weakest link in Mg?steel joints. The welding heat input and weld Al content have the significant effect on the joint strength. The joint strength increases with increasing the heat input from 1680 J/cm to 2093 J/cm, due to promoting Mg/steel interface reaction. When weld Al content is increased to 6.20%, the joint strength reaches 192 MPa, 80% of Mg alloy base metal strength. It is favorable to select the suitable welding heat input and weld Al content for improving joint strength.