Use of the DWTT Energy for Predicting Ductile Fracture Behavior in Controlled-Rolled Steel Line Pipes

Abstract

Abstract Prior to this time, it has been uncertain how ductile fracture toughness measurements of highly separated controlled-rolled steel pipes should be characterized to design pipelines against unstable ductile fracture propagation. Highly separated controlled-rolled steels are unique from conventional steels in that through-the-thickness splitting, or separations, can significantly effect the toughness.This paper will show that a better evaluation of the ductile fracture resistance of rising shelf controlled rolled steels than Charpy energy can be made by using the drop weight tear test (DWTT) energy at the service temperature. It has also been found that generally for higher toughness steels that a precracked notch DWTT specimen is needed to evaluate the propagation toughness. Both the pressed notch and precracked notch DWTT energies can be correlated to Charpy energy values, so that existing formulations for ductile fracture arrest in pipelines can be used with the DWTT energy. Comparisons of variou...