Friction Stir Lap Welding of Inconel 625 and a High Strength Steel

The joining of dissimilar hard metals such as high-strength steel and nickel-based alloy is required for shipbuilding offshore applications to enhance the strength, fracture toughness, corrosion resistance exposed parts. However, these alloys has remained a major challenge due limited solubility Fe Ni in each other, which commonly results formation brittle intermetallic compounds. We present here novel investigation on overlapped 625 marine-grade GL E36 plates by friction stir lap welding (FSLW). interface microstructure its influence joint strength are rigorously tested. main bonding mechanism found be mechanical mixing along interface. thermal cycles computed three-dimensional numerical heat transfer model their effects examined. Multiple micro tensile specimens extracted from zone examine through-thickness variation properties. welded characterized further evaluating microhardness distribution, lap-shear surface residual stresses.