Journals →  Chernye Metally →  2021 →  #8 →  Back

Casting and metal science
ArticleName Microstructural parameters as indicators of reliability of car castings made of 20GL steel
DOI 10.17580/chm.2021.08.04
ArticleAuthor R. A. Bogdanov, Yu. M. Markova
ArticleAuthorData

Bryansk State Technical University (Bryansk, Russia):

R. A. Bogdanov, Cand. Eng., e-mail: lpim-bra@yandex.ru

 

National Research Center “Kurchatov Institute” – Central Research Institute of Structural Materials “Prometey” (St. Petersburg, Russia):
Yu. M. Markova, Leading Eng., e-mail: yulia.markova@inbox.ru

Abstract

The complex influence of grain number, average area and grain hardness on the section of low-alloy cast steel 20GL of car castings “Side frame” and “Truck bolster” on the basis of statistical and microstructural analysis of samples obtained after open-hearth and electric arc melting and single and double heat treatment (HT), on increase of the toughness KCV-60 > 2.0. The frequency diagram of the relationship between the number of open-hearth and electric arc melts and the same level of impact toughness in 2018 with the imposition of grain microstructure and different levels of impact toughness (KCV-60 <2.0, KCV-60 ≥ 2.0 and above KCV-60 > 2.0∙102 kJ/m2). The relationship between the number of samples obtained by open-hearth melting and passed the 2nd HT, and the same level of impact strength in 2019 with the imposition of the grain microstructure from samples after the 1st and 2nd HT and different levels of impact toughness (KCV-60 < 2.0 and KCV-60 > 2.0∙102 kJ/m2). Microstructure of samples of low-alloy cast steel 20GL of car castings “Side frame” and “Truck bolster” types was studied by optical microscopy in the search for causes of falling toughness (KCV-60 <2.0). Statistical and microstructural analysis of the array of data on the size and average area of grains, their number and hardness in 20GL steel samples after single and double HT indicated different viscoplastic properties of these castings. The authors concluded that the grain size and hardness are the most important indicators of the microstructure of low-alloy steel 20GL and are unique in their effect on toughness.

keywords Heat treatment, microstructure, 20GL steel, toughness, average grain area, side frame, truck bolster, hardness
References

1. Gorynin V. I., Olenin M. I. Ways to increase the cold resistance of steels and welded joints: monograph. St. Petersburg: FGUP «TsNII KM «Prometey», 2017. 340 p.
2. Bogdanov R. А., Davydov S. V., Chukhin D. G. Influence of non-metallic inclusions on the toughness of 20GL steel car castings. Proceedings of the International. scientific and technical conference «Ensuring and improving the quality of mechanical engineering and aerospace products». Bryansk: BGTU, 2020. pp. 45–50.
3. Bogdanov R. А. Quality management of car castings from 20GL steel in the aspect of influence of nonmetallic inclusions. Mechanical engineering technology and materials science: proceedings of the international scientific-practical conference. Novokuznetsk: NITs MS, 2020. pp. 48–52.
4. Bogdanov R. А. Fractographic study of non-metallic inclusions in samples of cold-resistant steel 20GL. Collection of articles of the International. scientific-practical conference «Technological research: information support, algorithm, interpretation of results». Kazan: Sterlitamak: AMI, 2020. pp. 23–28.
5. Mishchenko V. G., Evseeva N. A. Influence of metallurgical processing on the structure and properties of multicomponent alloy steel. Steel in Translation. 2019. Vol. 49. No. 5. pp. 357–360.
6. Sych O. V., Khlusova E. I., Pazilova U. A., Yashina E. A. Structure and properties of the heataffected zone of low-alloy cold-resistant steel for arctic application. Inorganic Materials: Applied Research. 2018. Vol. 9. No. 6. pp. 1076–1089.
7. Nikulin S., Nikitin A., Belov V., Rozhnov A., Turilina V. et al. Acoustic emission analysis of crack resistance and fracture behavior of 20gl steel having the gradient microstructure and strength. Journal of Physics. 2017. Vol. 879. No. 1. pp. 120–129.
8. Fonstein N. Advanced high strength sheet steels: physical metallurgy, design, processing and properties. BRD: Springer International Publishing. 2015. pp. 1–396.
9. Fonstein N. Automotive steels: design, metallurgy, processing and applications. USA : Springer International Publishing, 2016. pp. 169–216.
10. GOST 32400–2013. Molded side frame and bolster beam of bogies for railway freight wagons. Specifications. Introduced: 01-07-2014. Moscow: Izdatelstvo standartov, 2013.
11. GOST 9454–78. Metals. Method for testing the impact strength at low, room and high temperature. Introduced: 01-01-1979. Moscow: Izdatelstvo standartov, 1978.
12. GOST 25593–83. Diamond pastes. Specifications. Introduced: 01-01-1984. Moscow: Izdatelstvo standartov, 1983.
13. GOST 4461–77. Reagents. Nitric acid. Specification. Introduced: 01-01-1979. Moscow: Izdatelstvo standartov, 1977.
14. GOST 5639–82. Steels and alloys. Methods for detection and determination of grain size. Introduced: 01-01-1983. Moscow: Izdatelstvo standartov, 1982.
15. Tsoy B., Lavrentyev V. V. Basics of creating materials with ultra-high physical characteristics. Edited by E. М. Kartashov, V. V. Shevelev. Moscow: Energoatomizdat, 2004. 400 p.
16. Astashchenko V. I., Zapadnova N. N., Shveeva Т. V., Zapadnova Е. А., Khalikov I. N. Improvement of requirements for the structure and composition of low-temperature steels. Vestnik Kazanskogo gosudarstvennogo tekhnicheskogo universiteta imeni A. N. Tupoleva. 2016. Vol. 72. No. 2. pp. 32–37.
17. Kabaldin Yu. G., Khlybov А. А., Anosov М. S., Shatagin D. А., Ryabov D. А. Analysis of cold resistance of metals with different types of crystal structure. Vestnik IzhGTU imeni M. T. Kalashnikova. 2019. Vol. 22. No 3. pp. 48–55.
18. Kabaldin Yu. G., Anosov М. S., Zinovev Yu. A. Study of cold resistance of materials for critical units of technical means working at low temperatures. Mashinostroenie: setevoy electronny nauchny zhurnal. 2016. Vol. 4. No. 2. pp. 14–17.
19. Reznik А. S., Bublik М. V. Cold-resistant AGS steels are innovative materials for operation in the Arctic. Actual problems of social and economic development of society: Collection of works on proceedings of the I National scientific practice conference of the FSBEI HE “KGMTU” branch. Edited by E. P. Masyutkin. Feodosiya, 2019. pp. 167–170.
20. Poletskov P. P., Denisov S. V., Nikitenko О. А., Gushina М. S., Stekanov P. А. Study of the influence of multistage heat treatment on peculiarities of the formation of the cryogenic structural steel microstructure. Vestnik Magnitogorskogo gosudarstvennogo tekhnicheskogo universiteta imeni G. I. Nosova. 2018. Vol. 16. No. 2. pp. 29–40.

Language of full-text russian
Full content Buy
Back