Prediction and optimization of weld bead geometry in oscillating arc narrow gap all-position GMA welding

Abstract

Oscillating arc narrow gap all-position gas metal arc (GMA) welding is primarily applied for the construction of large metal structure with the advantages of high efficiency and quality. According to the characteristic of weld shape, oscillating arc narrow gap all-position welding process can be divided into two parts, namely 0–180° and 180–360°, and in this paper the welding process of part 180–360° was researched. The statistical models for weld geometry were developed to predict and optimize weld bead geometry by using response surface methodology (RSM) based on central composite design (CCD), and the developed models were checked for their adequacy and significance by ANOVA. Then, the effects of wire feed rate, travel speed, dwell time, oscillating amplitude, and welding position on weld bead dimension were studied. Finally, the optimal welding parameters at welding positions from 180° to 360° were obtained by numerical optimization using RSM.