Microstructure and mechanical properties of hardox 400 steels welded by gmaw and fcaw processes

The aim of this study is to demonstrate the feasibility for joining of similar HARDOX 400 steels by gas metal arc welding (GMAW) and flux-cored arc welding (FCAW) processes. It was employed two types of massive welding wires (SG2 and SG3) and a flux-cored welding wire (E 71 T-1). The V groove butt joint of HARDOX 400 plates at horizontally position was employed. Optical microscopy, microhardness, bend and tensile tests have been performed to evaluate the weld zone characteristics and the performance of HARDOX 400 steel joints. The experimental results revealed that the tensile strength of the gas metal arc welded HARDOX 400 steels using with SG3 welding wire has been slightly lower than that of the joint with SG2 welding wire and higher than that of the joined by FCAW. It is concluded that the SG3 welding wire for GMAW can be employed to obtain the high mechanical properties of HARDOX 400 steel joints and the E 71 T-1 flux-cored welding wire for FCAW can be used to obtain the high welding speed and high weld depositions