Optimization of Submerged Arc Weld Process Parameters for Overlay Welding

Abstract

In this work was evaluated the influence of welding variables on weld beads applied by submerged arc process (SAW) with conventional current, aiming future application in overlays against corrosion. Segments of steel API 5L Gr B pipe as substrate, a 1.13mm-diameter electrode wire of nickel alloy, classification AWS ERNiCrMo-4 (Hastelloy C-276) as filler metal, and a flux neutral, basic and crowded were used. The variables voltage, wire feed speed and contact tip to work distance (CTWD) were analyzed, with the remaining parameters constant by a Design of Experiments with full factorial design in two-level and central points. Statistically significant and predictors mathematical models for responses dilution and average current, was obtained. However, for the response reinforcement/width, the model was characterized as statistically significant, but not predictive, and containing a lack of fit. The CTWD was the most significant variable to reducing the dilution.

Key-words:
Submerged arc welding; Weld overlay; Nickel alloy; Factorial design