Analysis of the Effect of MAG Welding Parameters on Microstructure and Mechanical Properties of TRIP 800 Steels with Finite Elements

In this study, MAG welding method was used. 2 mm thick TRIP 800 steel sheets are used in different welding parameters. Microstructures of welded joints were analyzed by taking OM (optical microscope) images from the main metal areas of the welding zone, HAZ (the region under the influence of heat). Depending on the welding parameters, (welding current: 40-50-60 Ampere, and welding speed: 5-7.5 mm/sn), ferritic, HAZ and martensitic phase regions were determined in microstructures in the main metal, HAZ and welding regions, respectively. The strengths of the welded connections were measured using the tensile test. Welding wire speed is chosen to obtain high penetration and ideal width welding seams. The strength of the welded bond using these parameters is determined as 1266 MPa as the highest value. It was determined that grain growth and martensitic phase transformations occur in fusion regions and result in brittle fracture. The Fusion zone and other regions were analyzed with finite elements.