The results of a study conducted over a number of years to characterize the elastic-plastic fracture properties of submerged arc weld metal are presented in this paper. The fracture properties of four different weldments were investigated at temperatures ranging from 24 to 288°C (75 to 550°F). Tests were conducted using both the conventional multiple-specimen J_Ic procedure as well as an automated single-specimen unloading compliance technique capable of generating the material J_I-R curve.

Test results obtained using the two different procedures are compared. The comparison indicates that while both test techniques generate comparable J-Δa data for a given test condition, J_Ic values from the respective sets of data can differ. This is attributed largely to the sparsity of data generated by the multiple-specimen technique and the nonlinearity of the J_I-R curves as revealed by the single-specimen technique.

Welding procedure was found to have a significant effect on measured toughness. A wide range of fracture behavior was observed. The welding parameters responsible for the observed behavior are discussed. The applicability of the current J_Ic and J_I-R curve test procedures over the wide range of crack growth behavior observed is discussed.