Análise de Tensões Residuais e Flechas em Soldas Planas de AISI 1020 Através de Ensaios de Tração, Microdureza Vickers e Mediçõees por Passe

Abstract

Temperature in the Heat Affected Zone (HAZ) changes according to its position, with time, and cooling conditions during solidification. This variation in temperature can produce phase changes along the crystalline structure and thermal dilatations that originate welding residual stresses. In this work, deflection per passes was analyzed with height measurements, residual stresses in Base Metal (BM) were analyzed with tension tests, in the Heat Affected Zone (HAZ) and Fusion Zone (FZ). The variation through-thickness inside the Heat Affected Zone (HAZ) region was evaluated using Vickers microhardness tests for four different welds: the first one without restraints, the second fully restrained, the third with parallel restrictions on the weld bead, and the fourth with perpendicular restrictions to the weld bead. The results for each weld allowed modeling the deflection through linear adjustments, determining the stress profile according to the type of restraints adopted, the region in which the welded joint shall fail, and identifying regions that present beneficial or harmful stresses according to the type of restrictions and loading. The study concluded that deflection can be mathematically modeled as a welding pass function, and residual stresses observed in the HAZ and Fusion Zone (FZ) increase through thickness.