Mechanical Characteristics and Stretch-Bend Failure Analysis on Ultra High Frequency Pulsed Gas Tungsten Arc Welded Thin FSS 409/ 430 Dissimilar Joints

Abstract The Mechanical and Stretch-Bend Failure studies on Ultra High Frequency Pulsed Gas Tungsten Arc Welded dissimilar joints of AISI409-AISI430 Ferritic Stainless Steels were conducted. Welding was conducted with 5 ultra high frequencies (50 Hz, 150 250 350 450 Hz). characteristics evaluation the included tensile strength, microhardness variations across welds creep. Microstructural metallurgical investigations weld cross section evaluation, comparing grain in high, medium low thermal heat affected zones, zones base material region. Stretch bend failure angular distortion, fracture limit strain, coefficient friction. Tests revealed that welded at 350Hz better, compared to other joints. Dissimilar joint fabricated exhibited 267 + 3 MPa as yield 409 6 ultimate strength. Its creep duration 72.7 mins (highest among joints). growth, partially coarse fine grains zones. Depending difference sizes, both sides welds, regions identified three distinct In AISI430 side; temperature austenitic, martensitic, delta ferrites AISI409 needle like martensitic structures, mixture ferritic-austenitic, δ-ferrite carbide precipitation found respectively. On increasing frequency pulses, distortion increased, fractures changed from tensile/shear type mixed type. shear tests, ratio radius: thickness, strain outer surface, sheet due stretching increased.