The effect of heat treatment on the microstructural and mechanical properties of welding valve steel working in high temperature conditions

In this study was also studied on GX12CrMoVNbN9-1 steel in the EN 10025-2 standard which is in the CrMo steel class, working under high temperature conditions. The name of this steel in ASTM standard is C12A. Effect of different heat treatments after welding on mechnical properties and microstructure was examined. Microstructure investigations of the welded steels which different heat treatment processes were applied were realized with optic microscope. In order to determine the mechanical properties of the materials, tensile and impact notch tests and hardness measurements were performed. The microstructures of the fractured surfaces were revealed by SEM investigations. In our study, mechanical properties and microstructures of the base metal, welding and heat affected regions were compared as a result of different heat treatments.