Microstructural changes in steel 10Kh9V2MFBR during creep for 40000 hours at 600°C

Published on Oct 20, 2015in Physics of Metals and Metallography0.877
· DOI :10.1134/S0031918X15080049
Alexandra Fedoseeva11
Estimated H-index: 11
,
P. A. Kozlov1
Estimated H-index: 1
+ 3 AuthorsRustam Kaibyshev60
Estimated H-index: 60
Sources
Abstract
In this work, we have investigated microstructural changes in steel 10Kh9V2MFBR (analog of P02 steel) after long-term creep tests at a temperature of 600°C under an initial stress of 137 MPa. Time to rupture was found to be more than 40000 h. It has been established that, in the zone of grips and in the neck region of the sample, the size of the particles of the M 23C6 carbides increases from 85 nm to 152 nm and 182 nm, respectively. In addition, large particles of the Laves phase with an average size of 295 nm are separated. The particles of these phases are located along high-angle boundaries. During prolonged aging and creep, the transformation of the M(C,N) particles enriched in V into the Z phase occurs. The average size of particles of the Z phase after prolonged ageing was 48 nm; after creep, it reached 97 nm. The size of M(C,N) particles enriched by Nb increases from 26 nm after tempering to 55 nm after prolonged aging and creep. It has been established that, in spite of an increase in the transverse size of the laths of tempered martensite from 0.4 to 0.9 µm in the neck of the sample, the misorientation of the lath boundaries does not increase. No recrystallization processes were found to develop in the steel during creep.
📖 Papers frequently viewed together
2014
3 Authors (Gao Jiaqiang, ..., Zhou Yedong)
2017
References40
Newest
#1M. I. Isik (MPG: Max Planck Society)H-Index: 3
#2Aleksander Kostka (MPG: Max Planck Society)H-Index: 38
Last. Gunther Eggeler (RUB: Ruhr University Bochum)H-Index: 68
view all 3 authors...
Abstract This paper reports on the formation of an Mo-rich Laves phase during high-temperature exposure and creep of a tempered martensite ferritic steel with 12 wt.% Cr and 1 wt.% Mo. The material was exposed to 550 °C for time intervals between 864 and 81,984 h. For comparison, a few creep tests were carried out at 550 °C and 120 MPa (duration between 864 and 12,456 h). All tests were interrupted after specific time periods and microstructures were investigated using transmission electron micr...
Source
#1Irina Fedorova (Belgorod State University)H-Index: 5
#2Andrey Belyakov (Belgorod State University)H-Index: 40
Last. Rustam Kaibyshev (Belgorod State University)H-Index: 60
view all 6 authors...
Abstract The precipitation of the Laves-phase in a low-carbon 9% Cr heat resistant steel was studied under conditions of aging and creep at 923 K. The Laves-phase of Fe2(W,Mo)-type with a ratio of Mo:W of 1:5 was observed on various boundaries in a tempered martensite structure after a long period of aging/creep. The Laves-phase precipitations provided effective stabilization of the tempered martensite lath structure and therefore promoted creep resistance, although their effect on the dislocati...
Source
#1I. I. Gorbachev (RAS: Russian Academy of Sciences)H-Index: 10
#2Vladimir V. Popov (RAS: Russian Academy of Sciences)H-Index: 25
Last. A. Yu. Pasynkov (RAS: Russian Academy of Sciences)H-Index: 7
view all 3 authors...
A model for describing the evolution of carbonitride precipitates of several compositions in steels at the stages of growth, dissolution, and coalescence is proposed. The kinetics of the growth and dissolution of carbonitrides in the Fe-Nb-Ti-C-N system is calculated based on the numerical implementation of this model.
Source
#1Alla Kipelova (Belgorod State University)H-Index: 10
#2Andrey Belyakov (Belgorod State University)H-Index: 40
Last. Rustam Kaibyshev (Belgorod State University)H-Index: 60
view all 3 authors...
The orientation relationships of M23C6 carbides in a martensitic creep resistant steel were studied. Almost all M23C6 carbides were located at (sub)grain boundaries after tempering and aging. The carbides were slightly elongated along the boundary planes and obeyed the Kurdjumov-Sachs, Nishiyama-Wassermann, and Pitsch orientation relationships as well as two new orientation relationships, that is and , with α-Fe matrix. On the other hand, the M23C6 particles in the neck portion of crept specimen...
Source
#1Valeriy Dudko (Belgorod State University)H-Index: 10
#2Andrey Belyakov (Belgorod State University)H-Index: 40
Last. Rustam Kaibyshev (Belgorod State University)H-Index: 60
view all 4 authors...
Structural changes in a 9 pct Cr martensitic steel during a creep test at 923 K (720 °C) under the applied stress of 118 MPa were examined. The tempered martensite lath structure (TMLS) was characterized by M23C6-type carbide particles with an average size of about 110 nm and MX-type carbonitrides with a size of 40 nm. The M23C6 particles were located on the packet/block/lath boundaries, whereas the MX precipitates were distributed homogeneously throughout TMLS. TMLS in the grip portion of the c...
Source
#1V. V. Popov (RAS: Russian Academy of Sciences)H-Index: 1
In this chapter possibilities of simulation of precipitate evolution in Fe-based alloys are analyzed. At first separate stages of the process are considered: growth, dissolution and coarsening, and then possibilities of simulation of all the stages of evolution including nucleation in the framework of a unified approach are analyzed. The results obtained are generalized on a case of simulation of precipitate evolution in multicomponent systems. The results of numerical calculations are compared ...
Source
#1Irina Fedorova (Belgorod State University)H-Index: 5
#2Alla Kipelova (Belgorod State University)H-Index: 10
Last. Rustam Kaibyshev (Belgorod State University)H-Index: 60
view all 4 authors...
Crept microstructures were examined in a 9 pct Cr martensitic steel with low carbon content. The steel was hot forged at 1323 K (1050 °C) followed by air cooling and then tempered at 1023 K (750 °C) for 3 hours. The tempered microstructure included numerous precipitates of MX-type carbonitrides and a small amount of M23C6-type carbides. Two groups of the MX-type particles were observed. The nanoscale MX-type precipitates appeared in the form of plate- and round-shaped particles. The plate-shaped...
Source
#1Alla Kipelova (Belgorod State University)H-Index: 10
#2Marina Odnobokova (Belgorod State University)H-Index: 8
Last. Rustam Kaibyshev (Belgorod State University)H-Index: 60
view all 4 authors...
The microstructure and creep behavior of a 3 pct Co modified P911 steel and standard P911 steel were examined. It was shown that the nanoscale M23C6 carbides and MX carbonitrides in the 3 pct Co modified P911 steel are not susceptible to significant coarsening under creep conditions. Also, coarsening simulations of M23C6 particles were performed for both steels. The rates of lath and particle coarsening in the P911 + 3 pct Co steel are remarkably lower than those in the P911. Increased stability...
Source
#1I. I. Gorbachev (RAS: Russian Academy of Sciences)H-Index: 10
#2Vladimir V. Popov (RAS: Russian Academy of Sciences)H-Index: 25
Last. A. Yu. Pasynkov (RAS: Russian Academy of Sciences)H-Index: 7
view all 3 authors...
A critical analysis of the available thermodynamic data for the Fe-V-Ti-C-N system has been performed, and a self-consistent thermodynamic description of this system has been proposed based on the CALPHAD (calculation of phase diagrams) method. Using the constructed thermodynamic description, we calculated the phase equilibrium states of the system under study and considered some laws of the effect of the alloy composition on the phase composition of steels alloyed with vanadium and titanium.
Source
#1Fengshi Yin (SDUT: Shandong University of Technology)H-Index: 2
#2Liqian Tian (SDUT: Shandong University of Technology)H-Index: 2
Last. Li Zhou (SDUT: Shandong University of Technology)H-Index: 3
view all 5 authors...
Two heats of 9 to 12 pct Cr ferritic/martensitic heat-resistant steels were prepared. One has an ultralow carbon content of 0.01 wt pct, whereas another heat has a normal carbon content of 0.09 wt pct. The effect of carbon content on microstructure and mechanical properties of 9 to 12 pct Cr ferritic/martensitic heat-resistant steels was studied. The results show that the ultralow-carbon steel contains bimodal, nanosized MX precipitates with high density in the matrix but few M23C6 carbide parti...
Source
Cited By15
Newest
Source
#1Alexandra FedoseevaH-Index: 11
#2Ivan NikitinH-Index: 2
Last. Rustam KaibyshevH-Index: 60
view all 4 authors...
Source
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...
Source
An analysis of mechanical properties has been performed for 12% Cr and 9% Cr steels by means of tension tests at 20 and 650°C and yield tests at 650°C and applied stresses of 200–100 MPa with a step of 20 MPa. The yield strength and ultimate tensile strength of the 12% Cr steel are, correspondingly, 614 and 710 MPa at 20°С and 365 and 390 MPa at 650°C. At both temperatures, the strength properties of the 12% Cr steel under tension are better than for the 9% Cr steel due to higher values of contr...
Source
#1I. NikitinH-Index: 5
#2Alexandra FedoseevaH-Index: 11
Last. Rustam KaibyshevH-Index: 60
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...
Source
#1Alexandra FedoseevaH-Index: 11
#2Ivan NikitinH-Index: 2
Last. Rustam KaibyshevH-Index: 60
view all 5 authors...
Source
#1Modassir Akhtar (NITW: National Institute of Technology, Warangal)H-Index: 9
#2Akhil KhajuriaH-Index: 11
Last. Shaju K. Albert (RRC: Indira Gandhi Centre for Atomic Research)H-Index: 28
view all 5 authors...
Formation of heat affected zone (HAZ) when welding is considered as weakest link across transition joint. Characterization of this zone is a key issue to reduce the effect of embrittlement; hence appropriate welding parameters were adopted. In the present study, HAZ simulation was done for boron modified P91 steel using Gleeble. It has been observed that matrix was martensitic in nature for coarse-grain HAZ (CGHAZ)/fine-grain HAZ (FGHAZ) whereas for inter-critical HAZ (ICHAZ), matrix was ferrite...
Source
#1Chenshuo Cui (NU: Northeastern University)H-Index: 2
#2Xiuhua Gao (NU: Northeastern University)H-Index: 15
Last. R.D.K. Misra (UTEP: University of Texas at El Paso)H-Index: 34
view all 6 authors...
ABSTRACTEffect of thermal treatment on the evolution of delta ferrite was studied in 11Cr–3Co–2.3W steel. Ferrite-forming alloy elements promoted the formation of delta ferrite during thermo-mechanical processing. The results of JMatPro and chromium equivalent calculations indicated that 11Cr–3Co–2.3W steel partially contained delta ferrite. Cr and W were segregated in/around delta ferrite. Delta ferrite had a bamboo-type morphology and it contained MX-type carbonitrides inside and the Laves pha...
Source
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...
Source
#1Alexandra FedoseevaH-Index: 11
#2Ivan NikitinH-Index: 2
Last. Rustam KaibyshevH-Index: 60
view all 4 authors...
Source
This website uses cookies.
We use cookies to improve your online experience. By continuing to use our website we assume you agree to the placement of these cookies.
To learn more, you can find in our Privacy Policy.