ASTM F1921

This test method covers the determination of a referencetemperature, T, which characterizes the fracture toughness offerritic steels that experience onset of cleavage cracking atelastic, or elastic-plastic Ke instabilities, or both. The specifictypes of ferritie steels (3.2.1)covered are those with yieldstrengths ranging from 275 to 825 MPa(40 to 120 ksi)andweld metals, after stress-relief annealing, that have 10 % orless strength mismatch relative to that of the base metal.