Effect of Beam Oscillation on Residual Stress and Corrosion Properties of AISI 316L Electron Beam Welds

Autogenous butt joints of AISI 316L stainless steel sheets were prepared by the electron beam welding process, using both static and oscillating beams. The joints were subjected to quality inspection under the x-ray radiography and x-ray computed tomography techniques, where they were found to be defect-free. The joints were characterized by performing corrosion tests in 3.5 wt.% NaCl and 1 M HNO3 solution, followed by residual stress measurement and microstructural investigations. Corrosion tests showed significantly higher aqueous corrosion resistance for oscillating beam joints than their static beam counterpart. Microstructural studies revealed a more homogeneous and fine-grained weldment region with retained delta-ferrite phase in lathy morphology for oscillating beam joints than the static beam joint. The corresponding residual stress measurements revealed a 20-30% reduction in tensile residual stresses for oscillating beam joints than their static beam counterpart.