3D Computational Welding Mechanics applied to IN625 Nickel-Base Alloy

Abstract

Design for sustainability asks for higher and higher performance materials and enhanced techniques devoted to realizing their joints. For advanced applications, the emphasis is on high-temperature strength, long-term creep life, phase stability, oxidation resistance, and robust and flexible welding processes. In this scenario, Ni-based superalloy Inconel 625 is successfully used for mechanical components operating at high temperatures and stresses, conditions that however may cause surface cracks. In the frame of circular economy, fusion welding is therefore used as a convenient repairing technique, as well. However, correct process parameters avoiding metallurgical and mechanical defects need to be known for each case-study. Computational welding mechanics is a proper tool used to avoid expensive trials, provided that the used numerical model can capture the main phenomena involved in welding process. In this work, a 3D numerical model of Inconel 625 multi-pass welding process is developed and validated through residual stresses X-Ray diffraction measurements. The model showed a good accuracy and was therefore proved to be a powerful tool for welding process design of such alloy.