Hardening Mechanisms of 12% Chromium Ferritic-Martensitic Steel EP-823

被引：2
作者：
Almaeva K.V. [1 ]
Litovchenko I.Y. [1 ]
Polekhina N.A. [1 ]
Linnik V.V. [1 ]
机构：
[1] Institute of Strength Physics and Materials Science of the Siberian Branch of the Russian Academy of Sciences, Tomsk
来源：
Steel in Translation | 2022年 / 52卷 / 12期
关键词：
dislocation hardening; dispersion hardening; ferritic-martensitic steel EP-823; grain boundary hardening; hardening mechanisms; high-temperature thermomechanical treatment; solid solution hardening; substructural hardening;
D O I：
10.3103/S0967091222120026
中图分类号：
学科分类号：
摘要：
Abstract: Based on experimental data on microstructure parameters of the reactor heat-resistant high-chromium (12% Cr) ferritic-martensitic steel EP-823, the main factors responsible for its strength properties have been identified. An analysis of the hardening mechanisms of this steel after processing is carried out according to the modes that provide a different level of its strength properties. Traditional heat treatment (THT) and advanced modifying high-temperature thermomechanical treatment (HTMT) are considered. The main mechanisms of steel hardening, regardless of the processing mode, are: dispersed hardening with nanosized particles of the MeX type (Me = V, Nb, Mo; X = C, N) according to the Orowan mechanism; grain-boundary hardening by high-angle boundaries of martensitic blocks and ferrite grains; substructural hardening by low-angle boundaries of martensitic lamellae; dislocation hardening due to the increased density of dislocations. The HTMT mode, which includes hot deformation in the austenitic region, leads to a significant modification of the structural-phase state of steel relative to THT: a decrease in the average sizes of martensite blocks and lamellae, as well as ferrite grains, an increase in the dislocation density and the volume fraction of nanosized particles of the MeX type. In this case, the corresponding contributions to the value of the yield strength of steel from grain boundary, substructural and disperse hardening increase in comparison with THT by 1.2, 1.3, and 1.8 times. The relative contributions of the considered hardening mechanisms to the yield strength of ferritic-martensitic steel EP-823 are discussed. It is shown that the closest to the experimental yield strength values after the two studied machining modes are obtained by using the Langford-Cohen model to estimate the value of substructural hardening. © 2022, Allerton Press, Inc.
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页码：1135 / 1141
页数：6
相关论文
共 33 条
[1]  
Cabet C., Dalle F., Gaganidze E., Henry J., Tanigawa H., Ferritic-martensitic steels for fission and fusion applications, J. Nucl. Mater., 523, pp. 510-537, (2019)
[2]  
Yvon P., Structural Materials for Generation: IV Nuclear Reactors, (2017)
[3]  
Odette R.G., Zinkle S.J., Structural Alloys for Nuclear Energy Applications, (2019)
[4]  
Zinkle S.J., Ghoniem N.M., Operating temperature windows for fusion reactor structural materials, Fusion Eng. Des., 51-52, pp. 55-71, (2000)
[5]  
Kurtz R.J., Odette G.R., Overview of reactor systems and operational environments for structural materials in fusion reactors, (2019)
[6]  
Klueh R.L., Elevated temperature ferritic and martensitic steels and their application to future nuclear reactors, Int. Mater. Rev., 50, pp. 287-310, (2005)
[7]  
Klueh R.L., Harries D.R., High-Chromium Ferritic and Martensitic Steels for Nuclear Applications, (2001)
[8]  
Totemeier T.C., Tian H., Simpson J.A., Effect of normalization temperature on the creep strength of modified 9Cr-1Mo steel, Metall. Mater. Trans. A, 37, pp. 1519-1525, (2006)
[9]  
Tan L., Hoelzer D.T., Busby J.T., Sokolov M.A., Klueh R.L., Microstructure control for high strength 9Cr ferritic-martensitic steels, J. Nucl. Mater., 422, pp. 45-50, (2012)
[10]  
He H., Wang H., He K., Liang X., Huang X., Comparative study on the microstructure and mechanical properties of a modified 9Cr–2WVTa steel by normalizing-tempering and quenching-partitioning treatments, Mater. Sci. Eng., A, 800, (2021)
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