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In the present work, the structure and phase composition of a high nitrogen austenitic steel were studied in dependence on the aging temperature from 600°C to 800°C. Age-hardening in the regimes 600°С, 5 h., 700°С, 0,5 h., и 800°С, 10 min. is accompanied with a decomposition of a [delta]-ferrite into a [sigma]-phase and an austenite, and simulteneous discontinuous decomposition of austenite with the formation of Cr[2]N-cells along grain boundaries and cells of austenite depleted by interstitials. The decomposition of [delta]-ferrite and austenitic grains occurs faster with increase in age-hardening temperature. Along with discontinuous decomposition of austenitic grains, there is a homogeneous (continuous) nucleation of Cr[2]N nitrides in those austenitic grains, which have not underwent discontinuous decomposition at the initial stages of aging.

The main objective of this study was the generalization and systematization of information on the structure and defects of metal in the welds of high-nitrogen steels after laser welding. The main attention was paid to the study of the porosity of the welds, the formation of cracks and the escape of nitrogen from the weld metal. Основными задачами данного исследования были обобщение и систематизация информации о структуре и дефектах металла в сварном шве высокоазотистых сталей после лазерной сварки. Основное внимание было уделено исследованию пористости швов, образованию трещин и уходу азота из металла шва.

We investigate the microstructure and microhardness of high-nitrogen austenitic steel Fe-20Cr-20Mn-2.6V-0.3C-0.8N (in wt. %) after upset and high-pressure torsion (HPT) (6GPa) for ?, ?, and 1 revolutions at room temperature. As the result of deformation, steel microhardness increases by 1.5 times after HPT. Slip, twinning, formation of localized deformation microbands, and precipitation hardening are the main deformation mechanisms under HPT, and the level of solid solution strengthening of steel remains high after deformation.

The microstructure and microhardness of high-nitrogen austenitic steel Fe-18Cr-23Mn-2,7V-0,2C-0,7N (in wt. %) after upset and high-pressure torsion (HPT) (6GPa) for 1/4, 1/2, and 1 revolutions at room temperature have been investigated. As the result of severe plastic deformation, steel microhardness increases by 1.5 times after HPT. Slip, twinning, formation of localized deformation microbands, ?-?-phase transformation, and precipitation hardening are the main deformation mechanisms under HPT. At the same time, the level of solid solution hardening of steel remains high after deformation.