Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: plate martensite

Sortuj według:

Ogranicz wyniki do:

Structural-phase transformations in 0.34C–1CRr–1Ni–1Mo–Fe steel during plasma electrolytic hardening

Rakhadilov B. K., Kozhanova R. S., Popova N. A., Nugumanova A. B., Kassymov A. B.

Materials Science Poland

2020

Vol. 38, No. 4

699--706

Structural-phase transformations in 0.34C–1Cr–1Ni–1Mo–Fe steel during plasma electrolytic hardening were investigated. Electrolytic-plasma hardening of steel samples was carried out by surface quenching with rapid concentrated heating of the surface by plasma action and subsequent rapid cooling by heat removal from the depth of the sample by electrolyte jet. Plasma electrolytic hardening was carried out in the cathode mode in an electrolyte made from an aqueous solution containing 20 % sodium carbonate and 10 % carbamide. To study the structural-phase states of the modified layer, we used the method of transmission diffraction electron microscopy on thin foils. The study of steel samples was carried out before and after the plasma electrolytic hardening. Initially, the steel was a mixture of pearlite and ferrite grains. Surface hardening of 0.34C–1Cr– 1Ni–1Mo–Fe ferrite-pearlite steel led to a change in the structural-phase state and the formation of a packet-lamellar martensite structure. It was found that PEH leads to distortion of the crystal lattice and the formation of long-range internal stresses, as well as to the release of small particles of cementite and carbide of M23C6 type, uniformly distributed throughout the volume of the material. Surface hardening led to the increase in all quantitative parameters of the fine structure (ρ, ρ±, χ, σL, σd).

The transformation of plate and lenticular martensite into austenite in Fe-(25-26) Ni type steels.

Karbownicka J., Szcześniak D., Jeleńkowski J., Jezierska E.

Inżynieria Materiałowa

2001

R. XXII, nr 4

430-433

The influence of the martensite morphology on characteristic temperatures and reversed transformation mechanism in two types of steel (Fe-Ni-Ti-Al, Fe-Ni-Ti-Mo) was investigated. Obtained from dilatometer results lead to conclusion that the transformation of plate martensite into the austenite starts and finishes in lower temperatures than the lenticular one. The transformation of lenticular martensite into reversed austenite is quicker and increases the dilatometric effect. The experiments with N25T2M steel (with dominant plate morphology of martensite) show that after the first cycle of the reversed transformation all formed martensite was isothermal.

Badano wpływ morfologii martenzytu na temperatury charakterystyczne i mechanizm przemiany odwrotnej w dwóch typach stali (Fe-Ni-Ti-Al, Fe-Ni-Ti-Mo). Otrzymane wyniki badań i porównanie z uprzednio otrzymanymi wynikami prowadzą do wniosku, że przemiana martenzytu płytkowego rozpoczyna się i kończy w temperaturze niższej niż soczewkowego. Przemiana martenzytu soczewkowego w austenit odwrotny jest szybsza i zwiększa efekt dylatometryczny. Doświadczenia przeprowadzone na stali N25T2M pokazały, że cały powstały w wyniku przemiany odwrotnej martenzyt jest izotermiczny.