CARACTERIZAÇÃO DE SOLDAS DISSIMILARES-AÇO INOXIDÁVEL AUSTENÍTICO AISI 316L COM LIGA DE NÍQUEL INCONEL 182

In this work, the dissimilar welding joint of the two AISI 316L austenitic stainless steel plates, using the nickel alloy filler metals Inconel 182, by SMAW process, with and without post welding heat treatment (PWHT), was studded. To determine the effect of the PWHT in the interface between base metal and weld metal, microhardness and bending test, optical microscopy, scanning electronic microscopy (SEM) and energy dispersive spectrometer analyses, were performed. The PWHT was performed in vacuum oven, 700°C for 3 hours. In sample with PWHT, in base metal, near the fusion line, the micro hardness value was decreasing, probably due to a relief of the stress generated during the welding. In weld metal with PWHT, the micro hardness value increase due the Nb and Ti carbide and nitrite carbide precipitation. The bending tests on root weld no cracking presentation, but with PWHT an increase in the opening of the grain boundary near the line of fusion, was observed in SEM, due to the increase in Cr and Mo carbide and sigma phase precipitation.