Progress on effects of alloying elements on bainite formation and strength and toughness of high strength steel weld metal

High-strength steel has excellent mechanical properties and develops rapidly, but the toughness of weld metal cannot be well solved, which hinders the large-scale application of high-strength steel to a certain extent. Thus it is urgent to improve the strengthening and toughening mechanism of high-strength steel weld metal and develop the corresponding welding consumables. This paper summarizes current main research methods of the influence of alloying elements on the microstructure transformation and mechanical properties, and the effects of alloying elements on the strength and toughness of high-strength steel weld metals. It briefly analyzes the influence mechanism of alloying elements on microstructure transformation and the relationship between alloy composition, microstructure transformation and mechanical properties. It is found that the multiple phase microstructure composed of bainite and acicular ferrite can make the weld metal obtain good toughness. In addition, the paper also discusses future development trend of high-strength steel welding, providing the guidance on the research and application of high-strength steel welding consumables. (topical review)