Integrated experimental FE analysis of temperature distribution, molten metal flow, and residual stress in GTAW dissimilar metal welds for engine exhaust system
摘要
Joining dissimilar metals is gaining popularity in the automotive, aerospace, marine, and energy industries due to its potential for weight reduction, cost savings, and improved performance under challenging operational conditions. Thermal fatigue at the hot and cold ends of an engine reduces the component lifespan in engine exhaust systems composed of identical materials. Corrosion at the hot end is caused by oxidation and spalling of the surface oxide layer, whereas pitting corrosion occurs at the cold end due to the condensation of combustion gases. These problems can be avoided by adopting dissimilar metal welds, which have superior heat and corrosion resistance. These issues can be remedied by utilizing a dissimilar metal. This study utilized Gas Tungsten Arc Welding (GTAW) to evaluate the weldability and characterization of two stainless-steel combinations: SS316L-SS410 and SS310-SS410 in sheet form. Taguchi L9 and L4 orthogonal arrays were used to optimize various process parameters such as welding torch angle, filler rod angle, filler diameter, welding speed, current, gas flow rate, pulse frequency, and wire feed rate. Filler electrodes ER316L and ER309, which met AWS A5.12 M/A5.12:2009 criteria, were investigated for their impact on weld quality. Experimental trials were augmented with finite element simulations in ANSYS 2021R1 to predict temperature distribution, molten metal flow behavior, and residual stress evolution. The findings underline the importance of process parameter selection in lowering heat-affected zone (HAZ) distortion and cold crack susceptibility while boosting weldment tensile strength, hardness, and structural integrity. It provides practical directions for creating defect-free and durable dissimilar weld connections in complicated engineering applications.