Volume 9, Issue 2 (March 1981)
Comparison of Methods for Fracture Toughness Determination in Steels
This study compares various test methods and estimation procedures that are available for determining the fracture toughness of steels. The ASTM Test for Plane-Strain Fracture Toughness of Metallic Materials (E 399), the energy rate test, and the multiple identical specimen crack growth resistance R curve test for elastic-plastic fracture toughness JIc determination are compared. Various formulations for plane-strain fracture toughness KIc and JIc estimation are also compared. Comparison of the test methods indicates that, for ductile steels, the multiple identical specimen R curve test is the most promising. It is suggested that the total areas be used for calculation of J from Rice's approximate formulation for three-point bend specimens of ductile steels and crack-contributed areas for brittle steel three-point bend specimens.