A Predictive Model for Tensile Strength of Plasma-Welded Joints in Sus 304 Stainless Steel Thin Sheets

In this research, we present the statistical analysis results derived from the plasma welding of SUS 304 stainless steel thin plates, employing the N27 orthogonal matrix design. The experimental investigations were conducted using the advanced LINCOLN C3-MATIC 32–33 welding system (USA), which is currently accessible in Vietnam. Our study focused on three pivotal parameters of plasma welding technology: the upper level plasma current (Ih, A), lower level plasma current (Ib, A), and welding speed (vh, cm/min). The evaluation criterion for welding quality is the weld joint tensile strength (σki, MPa) determined through destructive tensile testing. Test samples were meticulously extracted from the beginning, middle, and end regions of the weld and subsequently machined according to the Vietnamese standard TCVN 197:2002. The obtained test results from the 27 experimental planning nodes offer valuable statistical insights into the mechanical performance of the weld joint. The mean value of the tensile strength ranged from σki = 655.942 ÷ 720.37 MPa. These findings significantly contribute to the understanding of plasma welding for SUS 304 thin plates, facilitating further analysis and optimization of the welding process.