Welding Process of High-Performance S31603/Q420qENH Composite Steel Plate and Effect of Ferrite Content on Welding Joint Performance

With the increasing application of high-performance weather-resistant/stainless steel composite panels in the construction of bridges on plateaus with complex environment， welding of high-performance composite panels has become a key link. The welding process of high-performance S31603/Q420qENH composite steel plates was studied， and the composite test plates were welded using the independently developed base-layer weathering flux core welding wire JWT60NHQ， transition layer JWE309LMoT1-1 flux core welding wire， and cladding JWE316LT1-1 flux core welding wire， and the optimal welding process control plan was formulated to ensure the acquisition of stable welding joints. This study obtained transition layer welding materials with different ferrite contents through design and adjustment of the formula， analyzed the impact of the ferrite content of the transition layer welding material on various properties of the composite board joints， and tested the element distribution in each area of the welded joint， joint hardness， impact performance of -40 ℃， corrosion resistance， etc.Comprehensive analysis obtained the optimal welding process system， and it was concluded that when the ferrite number FN in the welded metal of the transition layer welding material was 10~13 （ferrite content was 10.8%~14.3%）， it can provide guarantee for the performance's stability of the composite panel joints.