Investigation of weldability of ARMOX 500T armor steel with hybrid plasma arc welding (HPAW), gas metal arc welding (GMAW) and cold metal transfer welding (CMT) methods

ARMOX 500T armor steel, which is used as an armor material in defense industry, was investigated with Hybrid Plasma Arc Welding (HPAW), Gas Metal Arc Welding (GMAW) and Cold Metal Transfer Welding (CMT) methods and the results were analyzed and compared with each other. Welding operations were carried out with robotic system welding machines. In this thesis, metallurgical and mechanical properties of ARMOX 500T armor steel joining together with different welding methods by using ESAB OK Autrod 16.95 additional filler wire were investigated. In order to observe the metallurgical features and diffusion status of the source region and source affected area (ITAB), SEM images were examined by optical microscope and EDS analysis was performed to analyze the chemical distribution after welding. X-ray Radiographic Inspection with welding defects called crack, pore, gas gap etc. negativity has been tested. To determine the effects of welding methods on mechanical properties, vickers hardness, tensile, bending and notch impact tests were applied to the welded samples. Source diffusion conditions on both optical microscope and SEM images were investigated. In HPAW and GMAW welding methods, diffusion has occurred between the main material and the weld metal. There was not enough diffusion in the CMT welding method. In this study, it has been observed that the temperature formed due to the welding methods applied affects the diffusion states and thus the mechanical properties of the experimentally joined material. ARMOX 500T armor steel used in the defense industry was experimentally combined with all three welding methods.