Effect of Hydrogen and Strain-Induced Martensite on Mechanical Properties of AISI 304 Stainless Steel

Abstract

Plastic deformation and strain-induced martensite (SIM, α 1 ) transformation in metastable austenitic AISI 304 stainless steel were investigated through room temperature tensile tests at strain rates ranging from 2ˆ10´6 to 2ˆ10´2/s. The amount of SIM was measured on the fractured tensile specimens using a feritscope and magnetic force microscope. Elongation to fracture, tensile strength, hardness, and the amount of SIM increased with decreasing the strain rate. The strain-rate dependence of RT tensile properties was observed to be related to the amount of SIM. Specifically, SIM formed during tensile tests was beneficial in increasing the elongation to fracture, hardness, and tensile strength. Hydrogen suppressed the SIM formation, leading to hydrogen softening and localized brittle fracture.

Understanding and mitigating hydrogen embrittlement of steels: a review of experimental, modelling and design progress from atomistic to continuum

“…These methods involve bombarding a sample with a probe beam at MeV energy ranges, in order to create a nuclear reaction with specific target species within the host matrix. Common reactions include the 3 Heðd; pÞ 4 He reaction (7), as well as the (resonance) reaction (8).…”

Texture-tensile properties correlation of 304 austenitic stainless steel rolled with the change in rolling direction

“…The tensile tests were performed on a universal testing machine (INSTRON 8862) with a cross head velocity of 1 mm min −1 . It can be noted that the room temperature tensile test of austenitic stainless steel results in the strain-induced martensitic transformation during testing [18,19]. However, this has not been studied in the present work.…”

Effect of hydrogen on dislocation structure and strain-induced martensite transformation in 316L stainless steel

“…As hydrogen clearly induced brittle fracture with cleavage, the reduction in elongation by hydrogen charging in the H-charged 316L was attributed to the transition from ductile to brittle fracture modes. 30 Furthermore, as SIM increased the ductility (Fig. 2) and H-free samples displayed uniform ductile fractures with ne dimples and voids irrespective of strain rates ( Fig.…”

“…27 The nucleation of voids is associated with the type of defect in the crystal. [28][29][30] In contrast, the fracture mode of H-charged samples changed from mixed fractures, with dimples and cleavages, at a strain rate of 2 Â 10 À2 s À1 (Fig. 3c) to enhanced brittle fractures, characterized by cleavages across the surface, at a strain rate of 2 Â 10 À6 s À1 (Fig.…”