Influence of boundary conditions on the strengthening technology of a welded joint with a ball-rod hardener

Abstract

Abstract The article deals with the problem of assessing the influence of the boundary conditions for fixing a plate with a welded seam on the stress-strain state during hardening with a ball-rod hardener. Welded joints are currently a trouble spot of the destruction of heavily loaded structures. Analysis of the microstructure and strength characteristics of the welded joint of 09G2S steel showed that in the fusion and heat-affected zones, the strength decreases due to temperature effects. The problem of modeling the strengthening of a welded joint with a ball-bar hardener under various conditions of plate fixing: with a free and fixed lower face is considered. The FEM model is constructed and the comparison of the conditions of plate fixation is carried out, which makes it possible to assess the degree of hardening and to assess the residual stresses after hardening treatment. It is shown that strengthening of a plate with a free bottom face significantly changes the stress-strain state of the plate and redistributes residual stresses to the weld zone, where strengthening is undesirable.