The Effect of Welding Parameters on Microstructural and Mechanical Properties of HSLA S960QL Type Steel with Submerged Arc Welding

Abstract

In this study, S960QL steels were welded with submerged arc welding process in order to examine microstructural and mechanical properties. For the microstructural investigation, microscopical examination methods were used for weld zones. Tensile, impact toughness and micro hardness tests were made for different samples obtained from the weld zone and the base metal. The examinations of fracture surfaces were made by using optical microscope and scanning electron microscope. The flat type tensile strength values were near to the base materials. Charpy impact toughness tests were made for the base metal, the weld metal center line, the fusion line, the zone between weld metal centerline and the fusion line. Impact energy of the weld metal was obtained lower than the base metal. The lowest impact energy was obtained at the fusion line. Heat affected zone had the highest value in micro hardness tests. In microstructure evaluation, the interface of the fusion zone-heat affected zone and heat affected zone had coarser grain structure than the base metal. Alloy carbides dissolved because of the high temperature values occurred at heat affected zone.