大厚度EH36双丝气电立焊焊接接头性能研究

Microstructure and Properties of Welded Joints of EH36 by Two-electrode Electrogas Welding

目的评价80 mm厚船板EH36的大热输入性能。方法采用控轧控冷方法试制了80 mm厚的大线能量钢板,并进行热输入量为700 kJ/cm的双丝气电立焊试验,用金相显微镜观察微观组织,用试验机测试接头的力学性能。结果焊接接头抗拉强度为542 MPa,焊接接头–40℃冲击功在59 J以上,根部粗晶区为焊接接头的韧性薄弱区,这与其根部散热慢有关。结论试制的钢板满足超大热输入要求,焊接性能优异。

The purpose of this article is to evaluate whether 700 kJ/cm welded joints meet the technical requirements. The steel plate with a thickness of 80 mm was trial-produced by TMCP-ACC. The two-electrode electrogas welding method was used for welding, the microstructure at different positions was observed with an optical microscope, and the joint performance was tested with mechanical properties testing machines. The tensile strength of the welded joint is 542 MPa. The impact absorbed energy at –40 ℃ is above 59 J, and the toughness of the coarse-grained region at the root is not good, which is related to the slow heat dissipation at the root. The conclusion is that the mechanical properties of the welded joint at 700 kJ/cm are excellent.