Investigation of mechanical properties and hot corrosion behavior of friction welded AISI 304 and AISI 1021 steels

In the current study, friction welding of two different steels, namely low alloy steel and austenitic stainless steel was done. For conducting welding, an in-house experimental set-up was designed and fabricated. The steels were friction welded by using various axial pressures at a uniform circular speed. Influence of axial pressure on the joint strength of the friction welded specimens such as tension, impact toughness, torsion strength and microhardness were evaluated. Moreover, the weldments were also tested for high temperature corrosion resistance. The corrosion testing of the welded joints was carried out in a molten salt environment of Na₂SO₄ + V₂O₅ 60% at 650°C. Weight change data were used to establish the kinetics of corrosion. Based upon this data, the weldments showing best corrosion resistance was identified. Subsequently to understand the composition of oxide scale, the specimen was evaluated using SEM/EDS and X-ray diffraction techniques. (author)