Prediction of KIc in a high strength bainitic steel

Abstract In this work the stress intensity factor ( K Ic ) has been determined for a high strength bainitic steel, making reference to ASTM E 399 standard, which involves the use of complex geometry specimens. An experimental value of 1627 N mm −3/2 has been obtained for K Ic , which is equivalent to 51.4 MPa m 1/2 . It has been verified that Lescovsek’s expression, which predicts K Ic as a function of hardness (HRc) and the CVN Charpy impact test value, can be applied to steels with a bainitic microstructure, as the CVN value is more influential than HRc. The acceptable prediction of Lescovsek’s expression shows the way to improve the K Ic value in bainitic steels.