The Effect of Strain Rate on Hydrogen-Assisted Deformation Behavior and Microstructure in AISI 316L Austenitic Stainless Steel

Abstract

The influence of strain rate in the interval of (10−5–10−3) 1/s on room temperature tensile behavior, dislocation arrangement, deformation mechanisms, and fracture of austenitic stainless steel AISI 316L electrochemically charged with hydrogen was investigated. Independently on strain rate, hydrogen charging provides the increase in the yield strength of the specimens due to a solid solution hardening of austenite, but it slightly influences deformation behavior and strain hardening of the steel. Simultaneously, hydrogen charging assists surface embrittlement of the specimens during straining and reduces an elongation to failure, which both are strain rate-dependent parameters. Hydrogen embrittlement index decreases with increase in strain rate, which testifies the importance of hydrogen transport with dislocations during plastic deformation. The stress–relaxation tests directly confirm the hydrogen-enhanced increase in the dislocation dynamics at low strain rates. The interaction of the hydrogen atoms with dislocations and hydrogen-associated plastic flow are discussed.

Microstructure and Mechanical Properties of Structural Steels and Alloys

“…A total of 10 papers cover a wide range of structural metals and alloys. The majority of these papers focus on the mechanisms of microstructure evolution and the mechanical properties of metallic materials subjected to various thermo-mechanical, deformation, or heat treatments [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Readers who are interesting in structural steels may learn from comprehensive investigations of microstructure evolution and its effect on the mechanical properties of diverse steel types [ 1 , 3 , 5 , 7 , 8 ].…”

“…The majority of these papers focus on the mechanisms of microstructure evolution and the mechanical properties of metallic materials subjected to various thermo-mechanical, deformation, or heat treatments [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Readers who are interesting in structural steels may learn from comprehensive investigations of microstructure evolution and its effect on the mechanical properties of diverse steel types [ 1 , 3 , 5 , 7 , 8 ]. Four of these papers [ 1 , 3 , 7 , 8 ] present experimental investigations of strengthening mechanisms operating in high-strength steels subjected to various promising treatments including tempforming [ 1 ] and quenching–partitioning processing [ 7 ].…”

“…Some crucial features related to structure–property relationships are detailed for high-strength rebar [ 3 ] and a high-speed axle steel [ 8 ]. Hydrogen-assisted deformation behavior was clarified by Astafurova et al [ 5 ] for a 316 L austenitic stainless steel. Materials scientists working with aluminum alloys may find interesting a paper investigating changes in microstructure and properties of an Al-Fe alloy subjected to severe plastic deformation [ 6 ].…”

Effect of Hydrogen Charging on the Mechanical Properties of High-Strength Copper-Base Alloys, Austenitic Stainless Steel AISI 321, Inconel 625 and Ferritic Steel 1.4511

“…Several research papers indicate that for austenitic stainless steels, the resistance to HE increases with the stabilizing of the FCC phase [50][51][52][53][54]. Therefore, both a low M d30 temperature as well as high stacking fault energies above 43 mJ/m 2 improve the resistance to HE since the FCC is stabilized and the formation of deformation twins is postponed.…”