Formation and Dissolution of Carbides and Nitrides in the Weld Seam of X70 Steel by the Effects of Heat Treatments

Abstract

Welding assembly of steels HSLA (High Limit of Elasticity) occupies an important place in the mechanical industry and in the shaping industry of transport facilities, hydrocarbon storage and other industries. X70 steels have a very important place in the mechanical industry, naval and oil industry. Also, were interested by studying the effect of heat treatments (energy supply) on structural stability (formation and dissolution of carbides and nitrides) in the weld bead zones of X70 steel and the zones adjacent areas (HAZ and During welding, the weld bead undergone very large temperature variations until melting followed by a more or less rapid solidification (out of equilibrium thermodynamic state), which causes an evolution of the microstructure during application of heat treatments (supply energy), which subsequently affects the mechanical properties and / or the electrochemical behavior (corrosion). The type of heat treatment influences the diffusion and backscatter of the addition elements with respect to the formation of carbides and nitrides in the microstructure of the weld beads.