Specification of the optimal gas metal arc welding (GMAW) parameters to enhance the mild steel strength (MS1018)

Abstract

Arc fusion processes, such as high-efficiency gas metal arc welding (GMAW), have become increasingly prevalent in various industries. To optimize the GMAW parameters and enhance the strength of MS 1018, Monika and Chauhan conducted experiments using the low carbon steel filler wire (ER 70 S6). They used a Taguchi L9 OA (orthogonal array) to generate test data focusing on 3 GMAW parameters such as gas flow rate, arc voltage, and welding current. The performance characteristics considered were tensile strength (TS), weld zone hardness (WZH), and heat-affected zone hardness (HAZH). The effect of GMAW parameters investigated using the S/N (signal-to-noise ratio) transformation of individual test data, which is valid to account for variations observed in repeated tests. By conducting a thorough analysis of variance (ANOVA) on this transformed data, they were able to identify the optimal GMAW parameters for achieving high TS, WZH, and HAZH. Given that HAZH exhibited higher values than WZH, it was evident that TS had the most significant impact on the GMAW process. Consequently, the researchers established empirical relationships for TS, WZH, and HAZH in terms of the GMAW parameters. Their test data aligned reasonably well with the expected range of performance indicators, supporting the validity of their findings. Overall, Monika and Chauhan’s modified Taguchi approach, based on the L9 OA, allowed them to efficiently conduct a limited number of tests while obtaining comprehensive information on the optimal GMAW parameters for enhancing the strength of MS 1018.