PLASTICITY AND TRIAXIALITY IN STRUCTURAL STEEL AND ASSOCIATED WELD METALS

In order to assess the effect of stress triaxiality on the plasticity and ductility of the structural mild steel and the associated weld metals, the tensile tests on notched round bar specimens were performed. The results indicated that the strains to initiate failure for the boiler steel and weld metals were a strong function of stress states. Under the same triaxiality the failure initiation strain of J427 weld metal was the largest among these materials, and that of J422 weld metal was the smallest. Moreover, the material constant C values relating to the metallurgical characteristics were given for the experimental steel and weld metals.