Caracterização das microestruturas e da resistência a corrosão de revestimentos da mistura das ligas de níquel AWS ERNiCrMo - 3 E AWS ERNiCrMo - 4 soldados pelo processo MIG/MAG duplo arame

Abstract

In this work for metallurgical characterization of welding overlays composed by the mixture of alloys ERNiCrMo AWS–3 and AWS ERNiCrMo-4 welded by MIG / MAG double wire process, micrographic analyzes were performed by means of scanning electron microscopy (SEM). Similarity was observed between the precipitates at the top of the weld metal and in the interface with the substrate. The microstructure obtained by welding two alloys of both resulted in a mixture of microstructures obtained from welds with each alloy isolation. The test for evaluating the performance of the mixture for resistance to corrosion was performed according to ASTM - G 48, C method to determine the critical pitting temperature of the mixture of alloys. Samples of coatings with higher and lower dilution were used. The test result showed that the welded coating had higher critical pitting temperature than the alloy AWS ERNiCrMo-3 and similar to Alloy AWS ERNiCrMo-4