The Influence of Weld Joint position in Low Carbon Steel on Fatigue Life

Abstract

The influence of weld residual stress on crack propagation under fatigue loading of mild steels has been investigated using compact tension specimens (C.T.S). The residual stresses were formed due to welding processes. Both hardness and longitudinal residual strain were measured using standard hardness test and strain gauges technique. Experiments were conducted to calculate the retardation fatigue crack propagation rate (FCPR) due to thermal stresses. Test is done on welded compact tension specimen (C.T.S). The experimental results confirmed that high hardness formed in the welding region as well as in the heat affected zone. Also, high tensile longitudinal residual strain was observed in weld metal and heat affected zone (HAZ) followed by compressive residual strain. Fatigue tests revealed that higher (FCPR) in both weld metal zone due to longitudinal residual stresses, while the compressive residual stresses reduced the (FCPR) and sometimes stopped it