Fatigue Crack Propagation Behaviour in Welded Joints of High Tensile Strength Steel

Abstract

Fatigue tests have been conducted on HT80 as-welded and post weld heat treated weldments under four point bending. Fatigue crack was propagated in the direction of thickness from base metal to weld metal. The difference of hardness on the both sides of crack tip was found to influence the direction of fatigue crack propagation. The results of propagation rates plotted against ΔCTOD, all of the propagation data fell within the same scatter band, and differences of propagation rates due to the changes of microstructure and residual stress were not observed clearly in this relationship.