Fracture toughness and crack growth resistance of submerged arc and manual metal arc weldments in A533B plate

Fracture toughness and ductile crack growth resistance data are presented for submerged arc (SA) and manual metal arc (MMA) weldments in 130 mm thick A533B class 1 steel plate. Toughness tests were performed on 50 mm and 125 mm square single edge notched bend specimens over the temperature interval -1000C to +1000C. The fracture toughness at the onset of cracking in MMA and SA weld metals and heat affected zone (HAZ) material was inferior to that of the parent plate, in both ductile and brittle regimes of cracking. The ductile brittle transition temperature was observed to increase with increasing specimen size. Several Charpy impact test:fracture toughness correlations have been examined using the current results. These correlations were broadly, but not entirely, satisfactory in predicting lower bounds to the observed initiation fracture toughness values. (author)