Equivalence in evaluating hydrogen-assisted fracture strength of slow strain rate tensile and constant load tensile for three precipitation-hardened martensitic stainless steels: Effect of large-sized particles

Abstract

This study investigated the equivalence in evaluating hydrogen-assisted fracture strength undergoing slow strain rate tensile (SSRT) and constant load tensile (CLT) for three precipitation-hardened martensitic stainless steels containing second-phase particles of different sizes. For both PH13–8Mo and 17–4PH with nano-sized precipitates, the fracture strength was higher for SSRT than for CLT. However, for 15–6PH with both nano-sized precipitates and large-sized carbides, cracks at the larger-sized carbide/matrix interface led to the lower fracture strength for SSRT. Furthermore, we concluded that the hydrogen-assisted threshold fracture strength of CLT could be estimated by using SSRT if no large-sized particles were in high-strength steels.