Full Field Measurement of Plastic Flow Properties in a Multi-Pass Austenitic Stainless Steel Weld Specimen

Knowledge of constitutive material stress strain properties is important for reliable prediction of weld residual stress fields using analytical stress simulation techniques. The present work investigates the surface stress strain behaviour of a 3-pass groove-welded austenitic stainless steel disc. A relatively novel electronic speckled pattern interferometry (ESPI) technique was employed to monitor the surface deformation pattern across the weld, HAZ and parent metal of the specimens with very high spatial resolution. The deformation data was then analysed to determine the constitutive stress-strain property across the welded specimen. The analyses show very different patterns of proof stress variation across the pass I and pass III weld metal. The accumulated plastic strain in the pass I weld metal resulted in an increase of the 0.2% PS value by 175 MPa.