Hydrogen Embrittlement Behavior of Plastically Pre-Strained and Cathodically Hydrogen-Charged 316H Grade Austenitic Stainless Steel

• Published in: Crystals (Basel) Vol. 12; no. 10; p. 1419
• Main Authors: Falat, Ladislav, Čiripová, Lucia, Petryshynets, Ivan, Milkovič, Ondrej, Džupon, Miroslav, Kovaľ, Karol
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2022
• Subjects: Austenitic stainless steels; austenitic steel; Chemical properties; Electron backscatter diffraction; fractography; Hydrogen; Hydrogen charging; Hydrogen embrittlement; Hydrogenation; Indentation; Mechanical properties; microstructure; Nuclear power plants; Recrystallization; Stainless steel; Steel, Stainless; Tensile stress; tensile test; Tensile tests; Ultimate tensile strength; Yield stress; Slovakia; United States > US
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst12101419

In this work, the effects of electrochemical hydrogen charging of 316H grade austenitic stainless steel were investigated in order to characterize its hydrogen embrittlement (HE) resistance. The as-received 316H material was in a fully recrystallized (solution-annealed) material condition. The susceptibility to HE of the studied material was evaluated by determination of the embrittlement index from the results of conventional uniaxial tensile tests of nonhydrogenated and hydrogen-charged test specimens. The study was focused on the effects of two selected plastic pre-strain levels of tensile specimens on their resulting HE resistance. The selected pre-strains corresponded to the tensile stress conditions within the “yield stress–ultimate tensile strength” (YS–UTS) range and directly at the UTS point. The obtained embrittlement indices for the presently used pre-straining and hydrogen charging conditions indicated that the HE of the studied material states was small. However, it was revealed that the observed degradation of deformation properties of plastically pre-strained and hydrogen-charged materials was mainly caused by gradual plasticity exhaustion due to tensile straining, which well correlated with the observed effects indicated by electron backscatter diffraction analyses and indentation hardness measurements.