Effect of high tempering on the structure and properties of the metal of the heat-affected zone of welded joints of structural steels

Abstract

1. High tempering at 620–650°C with the object of reducing residual welding stresses leads to poorer strength characteristics of the base metal and of the metal of the HAZ of welded joints of steels VSt3sp, 09G2S, and 10KhSND and to increased plasticity; in steel with nitride strengthening 15G2AF the strength characteristics of the base metal and of the metal of the HAZ are somewhat improved, and plasticity is impaired. 2. The application of high tempering at 620–650°C does not increase the toughness of the metal of the HAZ of welded joints made with large heat input to steels VSt3sp, 09G2S, and 10KhSND. 3. In specifying high tempering for the purpose of reducing residual welding stresses, it is necessary not to be guided solely by the degree of reduction of the stress level but also to take into account the possible changes of the mechanical properties and of the toughness of the metal of the separate sections of the welded joints, and this also depends on the system of alloying the steel.