Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: electrolyte-plasma hardening

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).

Research of surfaсe hardening influence on the microstructure, microhardness and wear resistence 18CrNi3MoA-Sh steel

Skakov M., Bayatanova L., Sheffler M.

Tribologia

2012

nr 5

147--153

The research shows the results of electrolyte-plasma treatment influence on structure-phase state, mechanical properties and wear-resistance of drilling tool steel samples. The comparative analysis of the microstructure, microhardness, and wear-resistance of the samples in initial state and after electrolyte-plasma treatment is represented. It was found that 18CrNi3MoA-Sh steel has a fine-grained martensite-bainite microstructure after the treatment. It was determined that 18CrNi3MoA-Sh steel possesses high wear-resistance after electrolyteplasma treatment and that this technology is characterised by low power consumption and cost. The average initial state microhardness is 2800 MPa. The average microhardness on the bearing lane surface after electrolyte-plasma processing is 7500 MPa. Microhardness increases bay a factor of 2 to 2.5, indicating technology efficiency.

Wyniki badań przedstawiają wpływ obróbki elektrolotyczno-plazmowej na stan strukturalno-fazowy, własności mechaniczne i odporność na zużywanie próbek stali na narzędzia wiertnicze. W pracy przedstawiono analizy porównawcze mikrostruktury, mikrotwardości i odporności na zużywanie próbek w stanie wyjściowym i po obróbce. Stwierdzono, że martenzytyczno-bajnityczna mikrostruktura stali 18CrNi3MoA-Sh po obróbce jest drobnoziarnista. Zauważono, że obróbka podwyższa odporność stali na zużywanie, co jest korzystne przy jej niskim zapotrzebowaniu na moc i niskim koszcie. Wartość średnia mikrotwardości próbek w stanie wyjściowym wynosi 2800 MPa, natomiast po obróbce wartość średnia mikrotwardości wzrasta do 7500 MPa. Mikrotwardość stali po obróbce elektolityczno-plazmowej wzrosła więc 2–2,5-krotnie w odniesieniu do stanu początkowego, co świadczy o skuteczności zastosowanej obróbki.