Hydrogen embrittlement properties of ultra high-strength low alloy TRIP-aided steels with bainitic ferrite matrix

Abstract

Hydrogen absorption behavior and hydrogen embrittlement properties of 1000-1800 MPa grade ultra high-strength low alloy TRIP-aided steels with bainitic ferrite matrix were investigated. The TRIP-aided steels absorbed a large amount of hydrogen, compared with the conventional tempered martensitic and bainitic steels. It was expected that the absorbed hydrogen was principally trapped in interlath retained austenite films and along bainitic ferrite lath boundary. Superior hydrogen embrittlement performances such as low hydrogen embrittlement susceptibility and high delayed fracture strength were achieved in the TRIP-aided steel. This may be associated with hydrogen trapping effect and TRIP effect of retained austenite.