30CrMnSiNi2A钢电子束焊接接头的组织与性能研究

为了探究30CrMnSiNi2A钢电子束焊接接头的组织与性能，采用电子束焊接工艺对12 mm厚30CrMnSiNi2A钢进行了焊接，并对焊态及完全热处理态的接头进行了室温拉伸和冲击韧性试验。结果表明:该钢的电子束焊接工艺性良好；焊态及完全热处理态的接头拉伸断裂均位于母材，经完全热处理后的接头强度比焊态接头强度提高近一倍，略高于同状态下母材的强度，延伸率及断面收缩率与母材相当，室温冲击韧性略高于母材；焊态焊缝组织主要表现为粗大针状马氏体与残余奥氏体组织，经完全退火处理后焊缝及热影响区组织主要表现为回火马氏体组织和残余奥氏体组织，母材组织为回火马氏体及少量的残余奥氏体组织；接头与母材的冲击断裂均表现为韧性断裂。

Properties and Microstructure of Welded Joint of 30CrMnSiNi2A Steel Electron Beam Welding

In order to explore the microstructure and properties of 30CrMnSiNi2A steel electron beam welded joint，the welding process was used to weld the 12 mm thick 30CrMnSiNi2A Steel，and the tensile and impact toughness tests at room temperature were carried out for the welded and fully heat treated joints. The results show that the electron beam welding technology of the steel works well. The tensile fracture of the welded and fully heat-treated joints is located in the base metal. The strength of the joint after the full heat-treatment is nearly twice as much as that of the welded joint，slightly higher than that of the base metal under the same state. The elongation and the reduction of the section are equivalent to that of the base metal, and the impact toughness at room temperature is slightly higher than that of the base metal. The microstructure of weld seam is mainly the coarse acicular martensite and retained austenite. After full annealing，the microstructure of the weld and heat affected zone is mainly tempered martensite and retained austenite. The microstructure of base metal is tempered martensite and a small amount of retained austenite. The impact fracture of the joint and base metal is ductile fracture.