The dissimilar metal welds (DMWs) are used in several areas of the industries. In the nuclear power plant, this weld using nickel alloy welding wires is used to connect stainless steel pipes to low alloy steel components on the reactor pressured vessels. The filler materials commonly used in this type of weld are nickel alloys 82 and 182.. In this study, dissimilar metal welds composed of low alloy steel ASTM A-508 G3, nickel alloys 82 e 182 as weld metals, and austenitic stainless steel AISI 316L were prepared by manual shielded metal arc welding (SMAW) and gas tungsten arc welding techniques (GTAW). Samples were microstructural characterized by optical microscopy and scanning electron microscopy using energy dispersive X ray microanalysis (EDS). It was noticed that there was a microstructure consisting of austenite dendrites with the presence of precipitates with shapes and dimensions set by the thermal contribution and direction of welding. There was no significant variation of hardness along the weld joint, demonstrating the suitability of the welding parameters used.
Low alloy steel; Austenitic stainless steel; Dissimilar weld; Nickel alloys; Microstructural characterization
