I. Nikitin
ParticleUltimate tensile strengthFerrite (iron)Lattice (order)KineticsCreepPrecipitation hardeningComposite materialTetragonal crystal systemGrain boundary diffusion coefficientMartensiteMetallurgyMaterials scienceSolid solution strengtheningTemperingLaves phaseLathPhase formationStructural evolutionLong term ageingElongationBoronRheniumCarbideTungstenNucleationStrain (chemistry)Ostwald ripeningDiffusionStrengthening mechanisms of materialsPlasticityPrecipitation (chemistry)DissolutionStress (mechanics)MetastabilityAusteniteThermodynamics
9Publications
5H-index
34Citations
Publications 9
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Abstract The coarsening of Laves phase in a Re-containing 10% Cr-3% Co-3% W steel during both creep and ageing at 923 K was investigated. The depletion of W solutes from the ferrite matrix is accompanied with the precipitation of Laves phase, wherein creep strain accelerates both these processes. The equilibrium W content in the ferritic matrix of 1.24 wt% and the volume fraction of Laves phase of 1.6% is reached after 500 h of creep and 1000 h of ageing. This is related to lower activation ener...
1 CitationsSource
Abstract The Z-phase (CrVN) precipitation in a 9% Cr–3% Co martensitic steel during creep at 923 K and 948 K has been investigated with aim to establish the effect of temperature on the nucleation mechanism of these particles and their coarsening behavior. Ostwald ripening of VX carbonitrides strongly affects these processes. An increase in creep temperature significantly accelerates the transformation of the nanoscale MX carbonitrides into the Z-phase particles causing the Z-phase nucleation in...
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#1Alexandra FedoseevaH-Index: 10
#2I. NikitinH-Index: 5
Last. Rustam KaibyshevH-Index: 58
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Abstract The nucleation of the Laves phase particles in a Re-containing 10% wt. Cr-3% Co-3% W steel with a low nitrogen and a high boron contents during creep is characterized by distinctive features. The precipitation process can be written as M23C6 carbide → M6C carbide → Laves phase. The nucleation of all phases in this precipitation sequence is heterogeneous. The M23C6 carbides precipitate on the boundaries of martensitic structure during tempering at temperature of 770 °C. The M6C (Fe3W3C) ...
5 CitationsSource
#1I. NikitinH-Index: 5
#2Alexandra FedoseevaH-Index: 10
Last. Rustam KaibyshevH-Index: 58
view all 3 authors...
The contributions from the martensitic laths, dislocations, secondary phase particles, and supersaturated solid solutions to the overall strength of the 12%Cr–3%Co–2.5%W creep-resistant steel with low N and high B contents were calculated after various heat treatments consisting of normalizing followed by medium-temperature tempering. An increase in the normalizing temperature from 1050 to 1150 °C led to an increase in the average size of the prior austenitic grains from 44 to 68 μm, but the δ-f...
7 CitationsSource
#1Alexandra FedoseevaH-Index: 10
#2I. NikitinH-Index: 5
Last. Rustam KaibyshevH-Index: 58
view all 4 authors...
Abstract Re-containing 10Cr-3Co-3W martensitic steel with low nitrogen and high boron contents exhibited a rupture time of 10,987 h at 650°C/140 MPa. This superior creep resistance was caused by partially saved tempered martensite lath structure due to precipitation of M23C6 carbides and Laves phase chains on lath boundaries as well as their high resistance to coarsening. M23C6 carbides were characterized by decreased interfacial energy that resulted in the retention of the orientation relations...
5 CitationsSource
#1Alexandra FedoseevaH-Index: 10
#2I. NikitinH-Index: 5
Last. Rustam KaibyshevH-Index: 58
view all 4 authors...
Abstract 9–12%Cr martensitic steels are perspective materials for critical components of new high-efficiency power plants working at ultra-supercritical parameters of steam. Addition of 0.2% rhenium in the experimental steel improved the short-term creep strength at 650 °C. Comparison of kinetics of tungsten depletion from the matrix in different high-Cr martensitic steels showed that rhenium in the experimental 10Cr-3Co-3W-0.2Re steel did not lead to retaining an increased amount of solute W in...
8 CitationsSource
#1Alexandra FedoseevaH-Index: 10
#2I. NikitinH-Index: 5
Last. Rustam KaibyshevH-Index: 58
view all 4 authors...
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Abstract The size and distribution of Cr(V,Nb)N (Z-phase) particles in a 9Cr-3Co-2W-0.6Mo-0.1Ni-0.2V-0.06Nb-0.1C-0.05N-0.005B steel subjected to creep rupture test during 11,151 h at 650 °C under an applied stress of 100 MPa were studied. The replacement of V-rich (V,Nb)(C,N) carbonitrides by Z-phase was accelerated by plastic flow as suggested by a comparative analysis of these particles in different portions of crept specimen, namely, the grip section, the portion of uniform elongation, and th...
9 CitationsSource