On the possibility of local measurement of crack resistance of structural steels taking into account the structure
The scale of heterogeneity of the structures of steels and alloys can be rather large both within one sample and within a product. The procedure adopted in practice for determining the integral values of crack resistance characteristics cannot always reflect this circumstance. In this regard, it is...
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| Format: | Article |
| Language: | English |
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Togliatti State University
2024-03-01
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| Series: | Frontier Materials & Technologies |
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| Online Access: | https://vektornaukitech.ru/jour/article/view/909/861 |
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| author | Maxim I. Sergeyev Egor V. Pogorelov Elina A. Sokolovskaya Aleksandr V. Kudrya |
| author_facet | Maxim I. Sergeyev Egor V. Pogorelov Elina A. Sokolovskaya Aleksandr V. Kudrya |
| author_sort | Maxim I. Sergeyev |
| collection | DOAJ |
| description | The scale of heterogeneity of the structures of steels and alloys can be rather large both within one sample and within a product. The procedure adopted in practice for determining the integral values of crack resistance characteristics cannot always reflect this circumstance. In this regard, it is necessary to develop methods for assessing the crack resistance of a medium with a heterogeneous structure. In this work, the authors determined the crack resistance of large forgings made of heat-hardenable 38KhN3MFA-Sh steel (0.38%C–Cr–3%Ni–Mo–V) based on the critical crack opening δс and the J-integral. The presence of critical stages in the development of a ductile crack during testing was assessed by acoustic emission measurements. In combination with the obtained methods of digital fractography of 3D images of fractures, this allowed relating the shape and position of the leading edge of each crack jump to the load-displacement diagram. Measuring the crack opening geometry during the test showed the possibility of determining directly the coefficient of crack face rotation when estimating δс. In general, this allowed constructing a map of the distribution of parameter δс values over the thickness of the sample and estimating the scale of the scatter in crack resistance within one sample – up to 30 %. Such a localization of measurements, primarily of the δc parameter, is comparable to the scale of heterogeneity in the morphology of various types of structures, which was assessed based on the measurement of digital images of the dendritic structure, the Bauman sulfur print, non-metallic inclusions on an unetched section, and ferrite-pearlite banding in the microstructure. This makes it possible to link local crack resistance values to various fracture mechanisms and their accompanying structural components. |
| first_indexed | 2024-04-24T12:03:33Z |
| format | Article |
| id | doaj.art-f13e5b7e5a5845c49acc019ed88de309 |
| institution | Directory Open Access Journal |
| issn | 2782-4039 2782-6074 |
| language | English |
| last_indexed | 2024-04-24T12:03:33Z |
| publishDate | 2024-03-01 |
| publisher | Togliatti State University |
| record_format | Article |
| series | Frontier Materials & Technologies |
| spelling | doaj.art-f13e5b7e5a5845c49acc019ed88de3092024-04-08T12:42:50ZengTogliatti State UniversityFrontier Materials & Technologies2782-40392782-60742024-03-011718110.18323/2782-4039-2024-1-67-7On the possibility of local measurement of crack resistance of structural steels taking into account the structureMaxim I. Sergeyev0Egor V. Pogorelov1https://orcid.org/0000-0002-6768-5038Elina A. Sokolovskaya2https://orcid.org/0000-0001-9381-9223Aleksandr V. Kudrya3University of Science and Technology MISIS, Moscow (Russia)University of Science and Technology MISIS, Moscow (Russia)University of Science and Technology MISIS, Moscow (Russia)University of Science and Technology MISIS, Moscow (Russia)The scale of heterogeneity of the structures of steels and alloys can be rather large both within one sample and within a product. The procedure adopted in practice for determining the integral values of crack resistance characteristics cannot always reflect this circumstance. In this regard, it is necessary to develop methods for assessing the crack resistance of a medium with a heterogeneous structure. In this work, the authors determined the crack resistance of large forgings made of heat-hardenable 38KhN3MFA-Sh steel (0.38%C–Cr–3%Ni–Mo–V) based on the critical crack opening δс and the J-integral. The presence of critical stages in the development of a ductile crack during testing was assessed by acoustic emission measurements. In combination with the obtained methods of digital fractography of 3D images of fractures, this allowed relating the shape and position of the leading edge of each crack jump to the load-displacement diagram. Measuring the crack opening geometry during the test showed the possibility of determining directly the coefficient of crack face rotation when estimating δс. In general, this allowed constructing a map of the distribution of parameter δс values over the thickness of the sample and estimating the scale of the scatter in crack resistance within one sample – up to 30 %. Such a localization of measurements, primarily of the δc parameter, is comparable to the scale of heterogeneity in the morphology of various types of structures, which was assessed based on the measurement of digital images of the dendritic structure, the Bauman sulfur print, non-metallic inclusions on an unetched section, and ferrite-pearlite banding in the microstructure. This makes it possible to link local crack resistance values to various fracture mechanisms and their accompanying structural components.https://vektornaukitech.ru/jour/article/view/909/861heterogeneity of structurescrack resistanceacoustic emissionfractographyquality prediction in metallurgycritical crack openingcherepanov–rice integralnonlinear fracture mechanics |
| spellingShingle | Maxim I. Sergeyev Egor V. Pogorelov Elina A. Sokolovskaya Aleksandr V. Kudrya On the possibility of local measurement of crack resistance of structural steels taking into account the structure Frontier Materials & Technologies heterogeneity of structures crack resistance acoustic emission fractography quality prediction in metallurgy critical crack opening cherepanov–rice integral nonlinear fracture mechanics |
| title | On the possibility of local measurement of crack resistance of structural steels taking into account the structure |
| title_full | On the possibility of local measurement of crack resistance of structural steels taking into account the structure |
| title_fullStr | On the possibility of local measurement of crack resistance of structural steels taking into account the structure |
| title_full_unstemmed | On the possibility of local measurement of crack resistance of structural steels taking into account the structure |
| title_short | On the possibility of local measurement of crack resistance of structural steels taking into account the structure |
| title_sort | on the possibility of local measurement of crack resistance of structural steels taking into account the structure |
| topic | heterogeneity of structures crack resistance acoustic emission fractography quality prediction in metallurgy critical crack opening cherepanov–rice integral nonlinear fracture mechanics |
| url | https://vektornaukitech.ru/jour/article/view/909/861 |
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