Evaluating Steel Toughness Using Various Elastic-Plastic Fracture Toughness Parameters

The elastic-plastic fracture toughness results for 185 single-specimen, unloading compliance tests from 32 plates of 13 steel grades [yield strengths 228 to 924 MPa (33 to 134 ksi)] are summarized. J-integral (JIc), crack-tip-opening displacement (CTOD), and tearing modulus (T) values are determined for each of these completely ductile behaving tests using the latest testing and evaluation procedures. Three J computational methods and two graphical evaluation techniques for JIc are investigated. The effects of these on the subsequent JIc and T values are established. Correlations between various J and CTOD based parameters are presented. In addition, correlations between J, CTOD, and T parameters and Charpy V-notch impact levels are established. The influence of the various computational and graphical methods and different elastic-plastic fracture toughness parameters upon metallurgical comparisons resulting from inclusion control in various steels is reported.