Research progress on welding technology of Fe-Mn-Al-C low density and high strength automobile steel

With the rapid development of automobile industry and the increasingly stringent requirements of "energy saving and emission reduction",automobile lightweight has become an inevitable choice for the development of automobile industry.Fe-Mn-Al-C low density high strength steel is one of the potential materials for automobile manufacturing.It is very important to master its welding method and improve its welding performance.Based on the microstructure and properties,welding difficulties and main welding methods of Fe-Mn-Al-C low-density high-strength steel,the welding difficulties caused by precipitation of second phase,volatilization and segregation of alloy elements,grain growth and softening in heat affected zone,current mainstream welding technology and its application in Fe-Mn-Al-C low-density high-strength steel are reviewed.According to the characteristics of typical welding process,combined with the problems of precipitation of second phase,welding crack and composition segregation in the welding process of Fe-Mn-Al-C high strength steel,it is pointed out that laser arc hybrid welding,laser brazing,friction stir welding and other new welding technologies will have better advantages in solving the welding problems of this kind of steel,which are worthy of close attention in the future.