Affiliation:
1. Tula State Lev Tolstoy Pedagogical University
Abstract
The purpose of the work was to study of the regularities of changes in the physico-mechanical and corrosion properties of reinforcing steel 23Kh2G2T in hot-rolled and heat-treated (furnace tempering) states.Methods. The study of the physical and mechanical properties and resistance (long-term corrosion resistance) of bar reinforcement to stress corrosion cracking (SCC) was carried out on experimental melts of steel grade 23Kh2G2T. The choice of melts was made in such a way that their chemical composition corresponded, if possible, to the upper, middle and lower levels of the grade composition.To create experimental conditions as close as possible to operational ones, the tests were carried out in a boiling solution of nitrates (60% Ca(NO3)2 + 5% NH4NO3 + 35% H2O) at a temperature of 110°С and operating voltages σe = (0,1–0,8 )σВ. To elucidate the features of transformations occurring in steel during tempering, the temperature dependences of internal friction were taken from samples tempered at different temperatures.Processing of the results of the time dependence of the amplitude-independent internal friction was carried out according to the theory of Granato, Hikata, Lucke, which describes the kinetics of the return of internal friction due to the migration of point defects to dislocations.Results. It has been established that by controlling the chemical composition and technological regimes for the production of steel 23Kh2G2T, it is possible not only to sharply increase its resistance to cracking, but also to obtain a guaranteed complex of mechanical and corrosion properties. It was revealed that reinforcement made of 23Kh2G2T steel should be produced with mandatory tempering. The greatest resistance to stress corrosion cracking with practically unchanged strength for reinforcement made of steel 23Kh2G2T is provided by 2-hour tempering in the temperature range of 350…400°С.Conclusion. The results obtained can be used to establish patterns of behavior of various types of ingot, powder and composite materials with high dispersion in phase and structural components in various conditions and states.
Publisher
Southwest State University
Reference23 articles.
1. Kugushin A. A., Uzov I. G., Kalmykov V. V., Madatyan S. A., Ivchenko I. V. Vysokoprochnaya armaturnaya stal' [High-strength reinforcing steel]. Moscow, Metallurgy Publ., 1986. 272 p.
2. Aksenov S. E., Nikitin A. V., Zaruchevnykh A. V. Ekspluatatsiya zhelezobetonnykh konstruktsii na tsellyulozno-bumazhnykh kombinatakh [Exploitation of reinforced concrete structures at pulp and paper mills]. Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Stroitel'stvo i arkhitektura = Bulletin of Perm National Research Polytechnic University. Construction and architecture, 2015, no. 2, pp. 161–173.
3. Veshnyakov A. V., Zaruchevnykh A. V., Aksenov S. E., Nikitin A. V. [Experience of inspection of reinforced concrete structures operated in an aggressive environment]. Problemy sovremennogo betona i zhelezobetona. Sbornik trudov. Ch. 1. Betonnye i zhelezobetonnye konstruktsii [Problems of modern concrete and reinforced concrete. Collection of works. Pt. 1. Concrete and reinforced concrete structures]; ed. by M. F. Markovsky. Minsk, Strinko Publ., 2007, pp. 130–140. (In Russ.)
4. Gedvillo I. A., Zhmakina A. S. Korroziya stal'noi armatury na rannikh stadiyakh tverdeniya betona [Corrosion of steel reinforcement at the early stages of concrete hardening]. Korroziya: materialy, zashchita = Corrosion: materials, protection, 2014, no. 5, pp. 19–24.
5. Dronov A. V. Osobennosti razvitiya pittingovoi korrozii stal'noi armatury zhelezobetonnykh izgibaemykh elementov [Features of the development of pitting corrosion of steel reinforcement of reinforced concrete bendable elements]. Vestnik Belgorodskogo gosudarstvennogo tekhnologicheskogo universiteta im. V. G. Shukhova = Bulletin of the Belgorod State Technological University named after V. G. Shukhov, 2017, no. 3, pp. 32–36.