The Effect of Resistance Spot Welding Parameters on Microstructure and Strength of DP800 Steel Joints Using Response Surface Methodology

• Published in: Advances in materials science Vol. 22; no. 3; pp. 53 - 78
• Main Authors: Rajarajan, Chakkravarthi, Sonar, Tushar, Sivaraj, Paramasivam, Raja, Selvaraj, Mathiazhagan, Nallusamy
• Format: Journal Article
• Language: English
• Published: Gdansk Sciendo 01.09.2022; De Gruyter Poland
• Subjects: DP800 steel; Dual phase steels; Electric vehicles; Electrodes; hardness; Investigations; Lap joints; Materials science; Mechanical engineering; Mechanical properties; Metal sheets; Microstructure; Optimization; Regression analysis; Residual stress; Resistance spot welding; Response surface methodology; Shear strength; Statistical analysis; Strain hardening; tensile shear fracture load; Tensile strength; Variance analysis; weld nugget; Welding current; Welding parameters
• ISSN: 2083-4799; 1730-2439; 2083-4799
• DOI: 10.2478/adms-2022-0013

The main objective of this paper is to analyze the direct and interaction effect of resistance spot welding (RSW) parameters on microstructure and strength of DP800 steel joints using response surface methodology (RSM). The DP800 steel sheets were spot welded in straight lap and cross lap joint configuration using RSW. The relationship between the RSW parameters, tensile shear fracture load (TSFL) and nugget zone hardness (NZH) was established employing statistical regression analysis and validated using Analysis of Variance (ANOVA). The DP800 steel joints made using welding current of 5.0 kA, electrode pressure of 4.0 MPa, and welding time of 1.50 s displayed maximum STRAIGHT-TSFL of 21.7 kN, CROSS-TSFL of 17.65 kN, and NZH of 589 HV respectively.