Experimental Analysis of Residual Stresses in the Various Zones of Arc Welded EN-8 Steel

Residual stresses are internal stresses locked into a rigid part in the absence of external forces or thermal gradients. Residual stresses present in the material lead cracking in the material. Hence, the estimation of residual stresses becomes essential after fabrication processes like welding, casting, etc. In the present work, residual stress has been measured arc welded EN8 steel using high resolution x-ray diffraction method (HRXRD). EN8 steels are used in many machine parts such as axles, shafts, presses & punches parts, piston rods & gear rods. The base material (EN8 steel) has been joined using arc welding process. The residual stress analysis was carried out in the three zones namely, welded zone, heat affected zone (HAZ) and parent zone. In XRD technique, when the stress is positive then the dspacing increases and when it is negative then the d-spacing decreases. Distributions of residual stresses on the welded zone, heat affected zone and parent zone have been evaluated. The result shows that the residual stress distribution for all the zones is characterized by compressive stresses.