Effect of ER70s Filler Metal on Mechanical Properties and Corrosion Behaviour of Low Carbon Steel Produced by Gas Metal Arc Welding

Abstract

The Gas Metal Arc Welding (GMAW) process is leading the way in arc welding process growth because it is more efficient, economical, and of high quality. The effects of ER70s filler metal on mechanical properties and corrosion behaviour in low carbon steel with a base metal thickness of 12 mm are investigated in this study using robotic gas metal arc welding (GMAW). After the welding process, the quality, microstructure, and micro-hardness of each specimen were measured and the effect was studied. The immersion test was studied using weight loss and corrosion rate measurements for 1, 2, 4, 6, and 8 weeks in the absence and presence of 3.5wt. % NaCl. As a result, the microstructure displayed the different grain boundaries of each parameter that affected the welding parameters. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are used to characterise the surface morphology and pitting areas on the welded substrate. The corrosion rate of the welded sample immersed in 3.5wt. % medium was higher than in the absence of NaCl. The SEM results revealed that NaCl played an aggressive role in inducing the corrosion process and producing significant pits on the welded joint, particularly in the HAZ area. This research may provide a significant understanding of how the welding process, filler metal, and low carbon steel metal caused corrosion behaviour in the marine environment, particularly for oil and gas applications.