Electron Backscattered Diffraction Analysis Across the Welded Interface of Post Weld Heat Treated 2205 Duplex Stainless-Steel and 316L Austenitic Stainless-Steel Dissimilar Weldment

The aim of this work was to characterize the microstructure-mechanical response relationships in UNS N08825/AISI 316L welds by means of electron backscatter diffraction analysis. Welding was conducted by ERNiCrMo-3 and ER308L filler wires. It was indicated that a significant increase in fractions of low Σ coincidence site lattice (CSL) boundaries occurred in UNS N08825 heat-affected zones (HAZs), whereas a small number of the boundaries formed in the AISI 316L HAZs and weld zones were of low ΣCSL types. Abnormal grain growth took place in the HAZs leading to changes in the initial texture components of the alloys. It was also demonstrated that the type of the used filler wire was a factor influencing the microtexture components formed within the HAZs. According to the results of mechanical tests, the weldment employing the ERNiCrMo-3 filler wire exhibited superior hardness, tensile strength, and elongation. Moreover, the occurrence of the abnormal grain growth in UNS N08825 HAZs had no negative effects on the tensile response of the weldments as a result of the activation of texture strengthening mechanism. Based on the obtained results, the ERNiCrMo-3 filler metal was recommended to fabricate the joint.

Characterization of Microstructure, Microtexture, and Mechanical Response in UNS N08825 Superalloy/AISI 316L Stainless Steel Welds by Electron Backscatter Diffraction Analysis

Mahdi Babajani

Papers

Characterization of Microstructure, Microtexture, and Mechanical Response in UNS N08825 Superalloy/AISI 316L Stainless Steel Welds by Electron Backscatter Diffraction Analysis