Modeling of Gas Metal Arc Butt Welded AISI 304 Stainless Steel Joints Using Finite Element Analysis

3D FE method and its comparison with the experimental data is presented for predicting the depth of penetration and HAZ  in gas metal arc (GMA) welding of 10 mm thick AISI 304 stainless steel (base metal) welded with AISI 308SS filler using GMAW process. A single V-groove joint design with multi pass welding was used to complete the weld joint. With an aim of modeling a multi pass weld joint, FE code ANSYS was used, where a full simulation of GMA welding of non linear heat transfer analysis was carried out. Assuming that the welding heat source moved at a constant speed along a straight line, the temperature contours observed from the heat source become quasi-static or quasi-stationary. Aspects like, temperature-dependent thermal properties of AISI stainless steel above liquid phase, effect of thermal boundary conditions, and the element birth and death technique for the simulation of filler metal deposition, are included in the model. The heat input to the model is assumed to be a moving surface heat flux with Gaussian heat distribution.

Preliminary attempts of this work include modeling investigations by taking welding speed as one of the influential welding variables that affects, heat input and hence weld bead shape in welding, the depth of penetration and HAZ using bead on plate experiments. While comparing the simulation and the experimental results for depth of penetration and bead width, the percentage congruence achieved is approximately to be 80% for both low and high heat inputs. Simulated weld bead shapes both for bead-on-plate welds and the butt joints are represented showing a close correlation with the experimentally obtained weld bead shapes.

Eventually, the numerical analysis results and experimental results have a good agreement in the context of GMAW multi pass welded joint.