Dilution Control of Weld Overlay Superalloys Using Taguchi Method

The objective of this work was to optimize the operational conditions aiming to deposit weld overlays with a minimal dilution and iron content as low as possible, and a thickness of weld higher than 3 mm just in a single layer. The alloys studied were Inconel 625, Hastelloy C276 and Inconel 686. The ASTM A516 Gr 60 steel was used as substrate. The welds were performed by GTAW cold wire feed process. The Taguchi method was applied to design the experiments and to evaluate the influence of the variables. The results showed that the arc oscillation (weaving) has a strong effect on the penetration and dilution of welds. The confirmation test for the optimal settings indicated that the additive model of the Taguchi method was not only confirmed the excellent reproducibility, but also provides sufficient confidence in the factorial effects.