Assessment of units’ performance of CCM technological line

To assess operational reliability of technological units of continuous casting machine (CCM), quantitative indicator of efficiency has been applied. This indicator of efficiency describes ability of technical product to perform work assigned to it with a certain probability, or expectancy that this amount of work will be performed. This indicator is interesting for its optimal value, which being surpassed decreases machine ability to perform the necessary amount of work. Thus, the optimum point of machine operating time limits rational time portion of its use without repair with maximum efficiency. Workability of CCM as technological line as well as operability of its units was evaluated using statistical material obtained during the 15 years of operation of billet CCM. So, all units were divided into three essentially different groups according to conditions of their appointment, i.e. a group of units working with liquid metal, a group of units working with solidifying metal and a group of units working with solidified metal. Performance of each group of units is estimated in absolute and relative values. When assessing performance of CCM units in absolute values, units operating with liquid metal have the greatest performance. Its rational service life from repair to repair is 270 hours with reliability of 0.51. The smallest efficiency was manifested in units working with solidified metal. Its performance lasts 150 hours with reliability of 0.6. Average efficiency in relative units of all groups of aggregates is almost the same, which makes it possible to use this indicator at an early stage of assessing efficiency of both machine units and CCM as a whole.

1. Fischer L., Bausch J., Hüllen I., Fröhling C., Rzepcyk M., Brand T., Knopp I., Brass H.-G. The concepts of perspective modernization using tested and approved continuous casting technology. Chernye Metally. 2018, no. 9, pp. 40–47. (In Russ.).

2. Guindani A., Venturini R., Jungbauer A., Linzer B., Gelder S., Bragin S., Bernhard C. Arvedi. ESP – real endless strip production: The next generation of producing high-value steels started up. In: Proc. 2 nd Int. Conf. on Super High-Strength Steels, 17 − 20 Oct. 2010. Milano, 2010, pp. 1–11.

3. Schimmel R., Kirschner M. Modernization of moulds to provide efficiency rise of continuous casting of 70mm thin slabs. Chernye metally. 2018, no. 3, pp. 24–26. (In Russ.).

4. Yamasaki J., Miyahara S., Kodama M., Matsukawa T., Matsuno J., Suzuki K. The control of the surface temperature in the continuous slab casting by the on-line digital computer. In: 8 th IFAC World Congress on Control Science and Technology for the Progress of Society, Kyoto, Japan, 24-28 August 1981. Kyoto, Japan: 1981, vol. 14, no. 2, pp. 2639–2644.

5. Ho K., Pehlke R. Modeling of steel solidifikation using the general finite difference metod. In: 5 th Int. Iron and Steel. Congress Proc. 6 th Process Technol. Conf. Apr. 6 – 9, 1986. Warrendale. Vol. 6. 1986, pp. 853–866.

6. Mizikar E. Mathematical heat transfer model for solidification of continuous cast steel slabs. Trans. Of The Metallurgical Society of AIME. 1967, vol. 239, no. 11, pp. 1747.

7. Evstigneev A.I., Odinokov V.I., Sviridov A.V., Dmitriev E.A., PetrovV.V. Teoretiical prediction of crack formation in axisymmetric multilayer shell molds. Materials Science Forum. 2016, vol. 857, pp. 573–577.

8. Sotnikov A.L., Nagornyi V.M., Orobtsev A.Yu., Ptukha S.V., Rodionov N.A. Standardization of operating modes and vibration level of CCM mold. Metallurgicheskie protsessy i oborudovanie. 2013, no. 1, pp. 44–54. (In Russ.).

9. Grebenik V.M., Tsapko V.K. Nadezhnost’ metallurgicheskogo oborudovaniya (otsenka ekspluatatsionnoi nadezhnosti i dolgovechnosti). Spravochnik [Reliability of metallurgical equipment (estimation of operational reliability and durability). Reference book]. Moscow: Metallurgiya, 1989, 592 p. (In Russ.).

10. Augusti G., Baratta A., Casciati F. Probabilistic Methods in Structural Engineering. London: Chapman and Hall, 1984, 556 p.

11. Madsen H.O., Krenk S., Lind N.C. Methods of Structural Safety. Englewood Cliffs, Prentice-Hall, 1986, 403 p.

12. Barlow E.E., Proschan F., Hunter L.C. Mathematical Theory of Reliability. New York-London-Sydney: Wiley, 1965, 256 p.

13. Breipohl M. Probabilistic Systems Analysis. New York-LondonSydney-Toronto: John Wiley & Sons, Inc., 1970, 352 p.

14. Hahn G.J., Shapiro S.S. Statistical Models in Engineering. New York-London-Sydney: John Wiley & Sons, Inc., 1994, 376 p.

15. Zorin V.A., Bocharov V.S. Nadezhnost’ mashin [Reliability of machines]. Orel: Izd-vo OrelGTU, 2003, 548 p. (In Russ.).

16. evertsev N.A. Nadezhnost’ slozhnykh sistem v ekspluatatsii i otrabotke. Ucheb. posobie dlya vuzov [Reliability of complex systems in operation and working out. University manual]. Moscow: Vysshaya shkola, 1989, 432 p. (In Russ.).

17. Savel’ev A.N. Teoriya rabotosposobnosti tekhnologicheskikh mashin [Theory of technological machines workability]. Kemerovo: Kuzbassvuzizdat, 2008, 225 p. (In Russ.).

18. Savel’ev A.N. Use of the criterion of machine parts workability in calculation of their service life. Izvestiya. Ferrous Metallurgy. 1991, vol. 36, no. 10, pp. 84–86. (In Russ.).

19. Kravchenko I.N., Puchin E.A., Chepurin A.V., etc. Otsenka nadezhnosti mashin i oborudovaniya: teoriya i praktika. Uchebnik [Reliability assessment of machines and equipment: theory and practice. Textbook]. Kravchenko I.N. ed. Moscow: Al’fa-M; INFRA-M, 2012, 336 p. (In Russ.).

20. Svetlitskii V.A. Statisticheskaya mekhanika i teoriya nadezhnosti [Statistical mechanics and reliability theory]. Moscow: izd. MGTU im. N.E. Baumana, 2002, 504 p. (In Russ.).

21. Cramer H. Mathematical Methods of Statistics. Stockhol: Almqvist and Wiksells, 1946, 575 p.

22. Ryabinin I.A. Nadezhnost’ i bezopasnost’ strukturno-slozhnykh system [Reliability and safety of structurally complex systems]. St.-Peterburg: Politekhnika, 2000, 248 p. (In Russ.).

23. Barlow R.E., Proschan F. Statistical Theory of Reliability and Life Testing Probability Models. New York: Holt, Rinehart and Winston, 1975, 290 p.

24. Locks M.O. Reliability, Maintainability, and Availability Assessment. New York: Hayden Book Co., Inc., 1973.

25. Esary J.D., Proschan F. Reliability bound for systems of maintained and independent components. Journal of the American Statistical Association. 1970, vol. 65, pp. 329–338.

26. Henley E.J., Lynn J. Generic Techniques in Reliability Assessment Components. Holland, Leyden: Noordhoff Int., 1976, pp. 26–35.

27. Savelyev A.N., Severyanov S.S., Prokhorenko O.D. Features of operating modes of continuous casting machine’s technological equipment. Chernye metally. 2019, no. 6, pp. 15–22. (In Russ.).

28. Savel’ev A.N., Sever’yanov S.S., Savel’eva A.V. Modeling of operational reliability of CCM units as complex technical system. Vestnik Sibirskogo Gosudarstvennogo industrial’nogo universiteta. 2016, vol. 16, no. 2, pp. 23–28. (In Russ.).

29. Savel’ev A.N. Structural features of sustainably functioning complex technical system. Izvestiya. Ferrous Metallurgy. 1996, vol. 39, no. 12, pp. 53–58. (In Russ.).

30. Savel’ev A.N., Timoshenkov Yu.G., Bich T.A. Modeling of distribution of CCM elements by their reliability. Izvestiya. Ferrous Metallurgy. 2006, vol. 49, no. 8, pp. 46–49. (In Russ.).