In recent years, the incidence of low fracture toughness values in test-weld heat-affected-zones (HAZ) has increased. It is not known whether these local brittle zones (LBZ) are significant or, if so, how they affect the structural integrity of a welded structure. Although there is much disagreement on the previous points, it is widely agreed that, for the present, it would be unwise to ignore LBZs. In line with the latter philosophy, the oil industry has established recommended practices for the preproduction qualification of steel plates to be welded in offshore structures. Testing to this practice is described in the paper.
"Fracture Toughness of Weldments for Offshore Structures," Standardization News, v. 21, no. 3, March 1993, pp 34-37