The effect of groove welding on mechanical properties and microstructure of wear resistance steel plate by Submerged Arc Welding

Abstract

Aim of this research is to analyze the mechanical properties and microstructure of wear resistance steel plates joined by Submerged Arc Welding at different grooves welding. The welding current of 300 Ampere, voltage of 28 Volt and travel speed of 38 cm/min was applied. The microscopical examination methods were used for weld zones. Impact toughness and rockwell hardness test were obtained from the weld metal, heat affected zone and the base metal samples. The fracture surfaces were examined by using optical microscope. As results, there was no difference of hardness and microstructure among three grooves welding. The significant differences were detected at the weld zones. Base metal had the highest hardness value. Ferrite and pearlite phases were obtained at three weld zones, but the heat affected zone had coarser grain structure than the base metal. Weld metal volume and electrode length significantly affected the impact toughness of joint, where the larger of the weld metal volume and length of electrode fill in the groove welding, the higher of impact toughness. The lowest impact energy and toughness value were attained at V groove and the highest was at I groove. The fracture surfaces at all groove welds showed ductile fracture dominantly.