The recently standardized ASTM Test for Determining the Plane-Strain Crack Arrest Fracture Toughness KIa of Ferritic Steels (E 1221) was modified for use with BIS 690 steel, an Australian low-alloy, 700-MPa strength, quenched and tempered steel used for ship plate. Specimens of 50-mm thickness in longitudinal and transverse orientations were tested at -60°C with various depths of side groove. Specimen configurations somewhat outside the range of ASTM Test E 1221 were found to be useful for this steel and were suggested as modifications to the standard method. A different solution and expression for stress intensity factor were used to evaluate the tests and to develop a method for predicting the crack length at which a running crack will arrest. Good agreement was obtained between the observed and predicted crack lengths at arrest.
The wedge-loading arrangement of the crack-arrest test procedure was used for static fracture toughness tests. Procedures for static wedge-loading fracture toughness were proposed, particularly for comparisons with crack-arrest toughness test results obtained under similar test conditions. for the tests here, the static fracture toughness was more than twice the value of crack-arrest toughness.