BWELDY960焊接工艺性及接头力学性能研究

Study on Weldability of BWELDY960 Steel and Mechanical Properties of Welded Joint

对40 mm的BWELDY960高强钢的焊接冷裂敏感性和焊接接头的力学性能进行了试验研究。结果表明:焊前120℃预热,可以有效防止焊缝产生冷裂纹;使用T Union GM 120焊丝,采用激光-电弧复合打底焊、双丝MAG填充盖面焊焊接BWELDY960高强钢时,焊接接头具有良好的拉伸、弯曲和冲击性能。接头上部的焊缝组织为马氏体,上部的过热区组织为马氏体和贝氏体;根部的焊缝组织为贝氏体,根部的过热区组织为马氏体和贝氏体。焊缝和热影响区的硬度与母材硬度没有明显的区别,热影响区的软化不明显。

The cold cracking sensitivity and mechanical properties of welded joint of BWELDY960 steel with thickness of 40 mm were studied. The results show that preheating at 120~C before welding can effectively prevent the welding seam from cold cracking. When T Union GM 120 welding wire was used to weld BWELDY960 high strength steel by laser-arc composite backing welding and double-wire MAG filler and cover welding, the welded joint has good tensile, bending and impact properties. The weld microstructure on the upper part of the joint is martensite and the microstructure of the overheated zone is composed of martensite and bainite, and the weld microstructure at the root of the joint is bainite and that of the overheated zone at the root is martensite and bainite. The hardness of the weld and heat affected zone is not significantly different from that of the base metal, and the softening of heat affected zone is not obvious.