Metallurgical and Mechanical Behaviors of 309L-Si and ERNiCrMo-3 Dissimilar Weld on ASTM A182 F22 Steel

The present work aims to evaluate the metallurgical and mechanical behavior of dissimilar weld formed by 309L-Si and ERNiCrMo-3 (Inconel 625) electrodes combination on the ASTM A182 F22 steel with GMAW process. The welded joints were characterized by SEM, OM, tensile test and Vickers microhardness technique. The dissimilar interface formed in buttery of 309L and INC625 showed partially mixed zone (PMZ) formation and solidification microcracks that affected the mechanical properties in welded joint, presenting a fragile behavior. The F22 and INC625 interface presented high hardness regions with peaks greater than 400 HV. These regions were enriched by carbon due to the diffusion from F22 steel into the weld metal caused by tension relief heat treatment (TRHT).

本研究旨在评估采用熔化极气体保护焊（Gas Metal Arc Welding, GMAW）工艺，使用309L-Si与ERNiCrMo-3（因科乃尔625, Inconel 625）焊条组合，在ASTM A182 F22钢上制备的异种焊缝的冶金与力学行为。焊接接头通过扫描电镜（Scanning Electron Microscopy, SEM）、光学显微镜（Optical Microscopy, OM）、拉伸试验以及维氏显微硬度测试技术完成表征。309L与Inconel 625对接形成的异种界面出现了部分混合区（Partially Mixed Zone, PMZ）与凝固微裂纹，此类缺陷对焊接接头的力学性能产生不利影响，使接头呈现脆性断裂特性。ASTM A182 F22钢与Inconel 625的界面区域存在高硬度区，其硬度峰值超过400 HV。由于消应力热处理（Tension Relief Heat Treatment, TRHT）引发的碳元素从F22钢向焊缝金属扩散，上述高硬度区域发生了碳富集现象。