Microstructure and properties of 304L stainless steel submerged arc welding joint under different annealing conditions

The butt joint experiment of 304L stainless steel thick plate was carried out by submerged arc welding method. The microstructure and properties of 304L stainless steel welded joint were analyzed by observing the microstructure of welded joint, combining with the impact toughness of welded joint at -196℃ and the residual stress test under different annealing conditions. The results show that the microstructure of heat affected zone is austenite, and the weld zone is austenite + a small amount of austenite. The results show that the residual stresses in weld seam and heat affected zone change greatly after annealing, and the residual stresses are further released with the increase of annealing temperature. In impact test, the impact energy of heat-affected zone at -196℃ decreases sharply with the increase of annealing temperature, and the impact work in weld zone at -196℃ decreases sharply with the increase of annealing temperature. The impact work showed a steady downward trend.