ACTA

Influence of Hydrogen-Charging Regime on Strain Hardening and Deformation Mechanism of Hot-Rolled High-Nitrogen Austenitic Steel

V.A. Moskvina^{a, b}, E.G. Astafurova^a, G.G. Maier^a, E.V. Melnikov^a, N.K. Galchenko^a, S.V. Astafurov^a
^aInstitute of Strength Physics and Materials Science, Russian Academy of Sciences, Akademichesky av. 2/4, 634055 Tomsk, Russia
^bNational Research Tomsk Polytechnic University, Lenin av. 30, 634050 Tomsk, Russia

Full Text PDF

The effect of hot-rolling and electrochemical hydrogen-charging on strength properties, strain hardening and deformation mechanisms of a high-nitrogen austenitic vanadium-containing Fe-17Cr-24Mn-1.3V-0.2C-0.8N steel was studied by uniaxial tensile tests, scanning and transmission electron microscopy. Hydrogen-charging for 15, 37, and 43 h reduces a yield strength, an ultimate tensile strength and elongation in the steel specimens. Hydrogen-charging for 37-43 h leads to increase in strain-hardening coefficient at early degrees of deformation (up to 10%) compared to uncharged and 15 h-charged specimens. Hydrogen influences the deformation mechanisms of the high-nitrogen steel: besides dislocation slip, one of the main deformation mechanisms of hydrogen-containing steel specimens is mechanical twinning. Hydrogen-charging promotes twinning, microlocalization of a plastic flow and γ→ε martensitic transformation in the steel.

DOI:10.12693/APhysPolA.134.760
PACS numbers: 81.40.Lm