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
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.
引用
收藏
页码:1135 / 1141
页数:6
相关论文
共 33 条
[11]  
Vivas J., San-Martin D., Caballero F.G., Capdevila C., High-chromium (9–12Cr) steels: Creep enhancement by conventional thermomechanical treatments, Metal Heat Treatments, (2020)
[12]  
Hollner S., Piozin E., Mayr P., Caes C., Tournie I., Pineau A., Fournier B., Characterization of a boron alloyed 9Cr3W3CoVNbBN steel and further improvement of its high-temperature mechanical properties by thermomechanical treatments, J. Nucl. Mater., 441, pp. 115-123, (2013)
[13]  
Hoffmann J., Rieth M., Klimenkov M., Baumgartner S., Improvement of EUROFER’s mechanical properties by optimized chemical compositions and thermo-mechanical treatments, Nucl. Mater. Energy, 16, pp. 88-94, (2018)
[14]  
Xu Z., Shen Y., Shang Z., Zhang C., Huang X., Precipitate phases in ferritic/martensitic steel P92 after thermomechanical treatment, J. Nucl. Mater., 509, pp. 355-365, (2018)
[15]  
Tan L., Yang Y., Busby J.T., Effects of alloying elements and thermomechanical treatment on 9Cr reduced activation ferritic-martensitic (RAFM) steels, J. Nucl. Mater., 442, pp. S13-S17, (2013)
[16]  
Ioltukhovskiy A.G., Kondrat'ev V.P., Leont'eva-Smirnova M.V., Votinov S.N., Shamardin V.K., Povstyanko A.V., Bulanova T.M., Metallurgical aspects of possibility of 9–12% chromium steel application as a structural material for first wall and blanket of fusion reactors, J. Nucl. Mater., 233-237, pp. 299-307, (1996)
[17]  
Ioltukhovsky A.G., leontyeva-Smirnova M.V., Kazennov Y.I., Medvedeva E.A., Tselishchev A.V., Shamardin V.K., Povstyanko A.V., Ostrovsky S.E., Dvoryashin A.M., Porollo S.I., Vorobyev A.N., Khabarov V.S., Influence of operation conditions on structure and properties of 12% Cr steels as candidate structural materials for fusion reactor, J. Nucl. Mater., 258-263, 2, pp. 1312-1318, (1998)
[18]  
Litovchenko I., Almaeva K., Polekhina N., Akkuzin S., Linnik V., Moskvichev E., Chernov V., Leontyeva-Smirnova M., The microstructure and mechanical properties of ferritic-martensitic steel EP-823 after high-temperature thermomechanical treatment, Metals, 12, (2022)
[19]  
Almaeva K.V., Litovchenko I.Y., Polekhina N.A., Akkuzin S.A., Regularities of the deformed microstructure of ferritic-martensitic steel EP-823 after high-temperature thermomechanical treatment, J. Phys.: Conf. Ser., 1989, (2021)
[20]  
Almaeva K.V., Litovchenko I.Y., Polekhina N.A., Microstructure, mechanical properties and fracture of EP-823 ferritic/martensitic steel after high-temperature thermomechanical treatment, Russ. Phys. J., 63, pp. 803-808, (2020)