Joining of pressure vessel steels using MAG welding method and investigation of mechanical properties

In this study, P265GH and P355NH steels, which are mostly used in pressure vessel production, were joined by MAG welding. Visual (VT), radiographic (RT) and ultrasonic (UT) examinations, as well as optical microscope, microhardness, tensile, notch impact and bending examinations were carried out in the welding areas of the obtained joints. No errors out of tolerance were detected in visual inspection practices. In addition, no discontinuity was detected in the welded samples during radiographic and ultrasonic examinations. In the microstructural examinations, the formation of large and columnar-shaped weld metal grains oriented in the direction of heat flow was observed. In addition, in the microhardness measurements, the highest hardness value was obtained in the weld metal, followed by HAZ and the main material, respectively. In all tensile tests, ductile necking and rupture occurred from the main material. In the notch impact tests performed, it was determined that the impact toughness value of the HAZ region was higher than that of the weld metal. In bending tests, no visible defects were detected in the welded samples.