Generalized diagrams and equations of recrystallization of cold-deformed steel St

The recrystallization processes in steel St.3 inthe ferrite state were studied. Samples with diameter of 8 mmand with height of 10 mmwere deformed by compression at 20 °Cfor 20 to 80 %, annealed at 400 – 735 °Cfor a period from 5 minutes to 10 hours, and cooled in the air. On the samples, the grain size was determined in longitudinal sections (with respect to the compression axis). After separation of the entire array of experimental data (degree of deformation ε, temperature T and time τ of annealing, grain size D) into 3 groups (no recrystallization, beginning and end of the primary recrystallization), the equations of hyperplanes best sharing these groups were found by the method of discriminant mathematical analysis. Recrystallization is not observed if the temperature is below 465 °C, or if the degree of deformation is lower than 20 % for any combination of other parameters. The deformed structure completely recrystallizes if the experimental points are in the parameter range: T > 550 °C, ε > 40 %, τ > 30 min. The largest grain refinement (up to 7 – 10 μm) was obtained after deformation with a maximum degree (80 %). The first critical (physical) degree of deformation, after which the size of the recrystallized grain is larger than the original one, is absent. The second critical (technical) degree of deformation is 25 – 35 % for temperatures of 530 – 735 °C. At such degrees grain refinement was observed in comparison with the initial deformed state. Mathematical relation between the size of the recrystallized grain and the experiments’ parameters was analyzed in two ways: according to Arrhenius in the form D=Aε^Nτ^Mexp (-Q/RT) , and according to Hollomon with linear temperature dependence (D ~ T). The Arrhenius solution gave the following equation: log(D) = 2,08 – 0,33log(ε) + 0,023log(τ) – 967,31 1/T. Therefore, activation energy of the recrystallization process is found to be ~18,000 J/mol. In case of the Hollomon analysis, it was proposed to use the function Р_Н = T/1000 [СН – log(τ) + log(ε)] as the Hollomon parameter, and the Hollomon constant of CH should be found by numerical methods. For these conditions, the equation D = –21,317 – 0,034T + 0,0032log(τ) T – 0,0032log(ε)T was obtained. The accuracy of both descriptions, defined as the sum of deviations squares of the measured grain sizes from calculated, is equal to ~3,3 μm or (when normalized to an average value) ~20 %.

1. Lizunov V.I., Shkatov V.V., Molyarov V.G., Kanev V P. Control over the quality of steel in hot rolling by its structure. Metal Science and Heat Treatment. 1999, vol. 41, no. 3-4, pp. 186–189.

2. Lizunov V.I., Molyarov V.G., Korochkin E.A. In: Chernaya metallurgiya Rossii i stran SNG v XXI veke. Materialy konferentsii. T. 4 [Ferrous metallurgy in Russia and CIS countries in the 21st century. Conference proc. Vol. 4]. Moscow: Metallurgiya, 1994, pp. 39–43. (In Russ.).

3. Gorelik S.S. Rekristallizatsiya metallov i splavov [Recrystallization of metals and alloys]. Moscow: Metallurgiya, 1978, 568 p. (In Russ.).

4. Gorelik S.S., Kaputkina L.M., Dobatkin S.V. Rekristallizatsiya metallov i splavov [Recrystallization of metals and alloys]. Moscow: Metallurgiya, 2003, 452 p. (In Russ.).

5. Humphreys F.J., Hatherly M. Recrystallization and related annealing phenomena. Amsterdam: Elsevier, 2012, 128 p.

6. Doherty R., Hughes D., Humphreys F., Jonas J., Jensen D.J., Kassner M., King W., McNelley T., McQueen H., Rollett A. Current issues in recrystallization: A Review. Materials Science and Engineering A. 1997, vol. 238, no. 2, pp. 219–274.

7. Jacques P., Delannay F., Cornet X , Harlet Ph., Ladriere J. Enhancement of the mechanical properties of a low-carbon, low-silicon steel by formation of a multiphased microstructure containing retained austenite. Metallurgical and Materials Transactions A. 1998, vol. 29A, no. 9, pp. 2383–2393.

8. Tokizane M., Matsumura N., Tsuzaki K., Maki T., Tamura I. Recrystallization and formation of austenite in deformed lath martensitic structure of low carbon steels. Metallurgical and Materials Transactions A. 1982, vol. 13, no. 5, pp. 1379–1388.

9. Tsuji N., Maki T. Enhanced structural refinement by combining phase transformation and plastic deformation in steels. Scripta Materialia. 2009, vol. 60, no. 12, pp. 1044–1049.

10. Torres C.R., Sanchez F., Gonzalez A., Actis F., Herreara R. Study of the kinetics of the recrystallization of cold-rolled low-carbon steel. Metallurgical and Materials Transactions A. 2002, vol. 33A, no. 1, pp. 25–31.

11. Lu Y., Molodov D.A., Gottstein G. Recrystallization kinetics and microstructure evolution during annealing of a cold-rolled Fe– Mn–C alloy. Acta Materialia. 2011, vol. 59, no. 8, pp. 3229–3243.

12. Shtremel’ M.A. Prochnost’ splavov. Chast’ 2: Deformatsiya [Strength of alloys. Part 2. Deformation]. Moscow: ID MISiS, 1999, 518 p. (In Russ.).

13. Belomyttsev M.Yu., Mordashev S.V. Regularities of short-term creep of St3 steel. Izvestiya. Ferrous Metallurgy. 2015, no. 11, pp. 798-801. (In Russ.).

14. Rogel’berg I.L., Shpichinetskii E.S. Diagrammy rekristallizatsii metallov i splavov. Spravochnik [Diagrams of recrystallization of metals and alloys. Directory]. Moscow: Metallurgizdat, 1950, 280 p. (In Russ.).

15. Lin Y., Chen M.-S., Zhong J. Study of static recrystallization kinetics in a low alloy steel. Computation Materials Science. 2008, vol. 44, no. 2, pp. 316–321.

16. Mao H., Zhang R., Hua L., Yin F. Study of static recrystallization behaviors of GCr15 steel under two-pass hot compression deformation. J. of Materials Engineering Performance. 2015, vol. 24, no. 2, pp. 930–935.

17. Taheri A. K., Maccagno T., Jonas J. J. Effect of cooling rate after hot rolling and of multistage strain aging on the drawability of lowcarbon-steel wire rod. Metallurgical and Materials Transactions A. 1995, vol. 26A, no. 5, pp. 1183–1193.

18. Akbari E., Karimi Taheri K., Karimi Taheri A. The effect of prestrain temperature on kinetics of static recrystallization, microstructure evolution, and mechanical properties of low carbon steel. J. of Materials Engineering Performance. 2018, vol. 27, no. 5, pp. 2049–2059.

19. Qu H.P., Lang Y.P., Yao C.F., Chen H.T., Yang C.Q. The effect of heat treatment on recrystallized microstructure, precipitation and ductility of hot-rolled Fe–Cr–Al–REM ferritic stainless steel sheets. Materials Science and Engineering A. 2013, vol. 562, pp. 9–16.

20. Tal’bo Zh. Annealing behavior of puron. In: Fizicheskie i khimicheskie svoistva metallov vysokoi chistoty [Physical and chemical properties of metals of high purity]. Moscow: Metallurgizdat, 1964, pp. 183–222. (In Russ.).

21. Shen G., Zheng C., Gu J., Li D. Coupled simulation of ferrite recrystallization in a dual-phase steel considering deformation heterogeneity at mesoscale. Computation Materials Science. 2018, vol. 149, pp. 191–201.

22. Shi-Hoon Choi, Jae Hyung Cho. Primary recrystallization modeling for interstitial free steels. Materials Science and Engineering A. 2005, vol. 405, no. 1, pp. 86–101.

23. Suna G.S., Dua L.X., Hua J., Misra R.D.K. Microstructural evolution and recrystallization behavior of cold rolled austenitic stainless steel with dual phase microstructure during isothermal annealing. Materials Science and Engineering A. 2018, vol. 709, pp. 254–264.

24. Shkatov V.V., Lizunov V.I., Chernyshev A.P. Quantitative comparison of the kinetics of isothermal and nonisothermal transformations. Izvestiya. Ferrous Metallurgy. 1990, no. 7, pp. 109–110. (In Russ.).

25. Shkatov V.V., Chernyshev A.P., Lizunov V.I. Kinetics of pearlite spheroidization in carbon steel. Physics of Metals and Metallography. 1990, vol. 70, no. 4, pp. 116–121.

26. Shkatov V.V., Chernyshev A.P., Lizunov V.I. Transformations in ferrite-pearlite structure of hot-rolled strip steel 09G2 at coils cooling. Izvestiya. Ferrous Metallurgy. 1990, no. 11, pp. 61–63. (In Russ.). (In Russ.).

27. Oyarza M., Martınez-de-Guerenu A., Gutierrez I. Effect of stored energy and recovery on the overall recrystallization kinetics of a cold rolled low carbon steel. Materials Science and Engineering A. 2008, vol. 485, no. 1, pp. 200–209.

28. Etesami S.A., Enayati M.H. Microstructural evolution and recrystallization kinetics of a coldrolled, ferrite-martensite structure during intercritical annealing. Metallurgical and Materials Transactions A. 2016, vol. 47A, no. 7, pp. 3271-3276.

29. Doherty R. D., Cahn R. W. Nucleation of new grains in recrystallization of cold-worked metals. Journal of the Less-Common Metals. 1972, vol. 28, pp. 279-296.

30. Mazaheri Y., Kermanpur A., Najafizadeh A., Kalashami A G. Kinetics of ferrite recrystallization and austenite formation during intercritical annealing of the coldrolled ferrite/martensite duplex structures. Metallurgical and Materials Transactions. 2016, vol. 47 A, no. 3, pp. 1040–1051.

31. Khimushin F.F. Zharoprochnye stali i splavy [Heat-resistant steels and alloys]. Moscow: Metallurgiya, 1969, 752 p. (In Russ.).

32. Rozenberg V.M. Osnovy zharoprochnosti metallicheskikh materialov [Fundamentals of high-temperature strength of metallic materials]. Moscow: Metallurgiya, 1973, 328 p. (In Russ.).

33. Garofalo F. Fundamentals of Creep and Creep-rupture in metals. New York and London, 1965. (Russ.ed.: Garofalo F. Zakony polzuchesti i dlitel’noi prochnosti metallov i splavov. Moscow: Metallurgiya, 1968, 304 p.).

34. Tamura M., Abe F., Shiba K., Sakasegawa H., Tanigawa H. Larson– Miller constant of heat-resistant steel. Metallurgical and Materials Transactions A. 2013, vol. 44a, pp. 2645–2661.

35. Adaskin A.M., Butrim V.N., Kremnev L.S., Kubatkin V.S., Sapronov I.Yu. Determination of the Hollomon parameter for a chromiumbase refractory alloy with the aim of predicting its properties. Metal Science and Heat Treatment. 2016, vol. 57, no. 9-10, pp. 610–613.

36. Adaskin A.M., Butrim V.N., Kubatkin V.S., Sapronov I.Yu. Strain hardening curves and mechanical properties of a chromium-base refractory alloy as a function of heat treatment and test temperature. Metal Science and Heat Treatment. 2016, vol. 57, no. 9-10, pp. 625–631.

37. Janjusevic Z., Gulisia Z., Mihalovic M., Pataric A. The investigation of applicability of tha Hollomon-Jaffe equation on tempering the HSLA steel. Chemical Industry and chemical Engineering Quarterly. 2009, vol. 15, no. 3, pp. 131–136.

38. Etesami S.A., Enayati M.H., Kalashami A.G. Austenite formation and mechanical properties of a cold rolled ferrite-martensite structure during intercritical annealing. Materials Science and Engineering A. 2017, vol. 682, pp. 296–303.

39. Wu H., Du L., Ai Z., Liu X. Static recrystallization and precipitation behavior of a weathering steel microalloyed with vanadium. J. of Materials Science Technologies. 2013, vol. 29, no. 12, pp. 1197–1203.

40. Gladshtein V.I. Estimation of the effect of stresses and temperature on damage accumulation in steam pipe bends by simulating the endurance of the metal by testing notched specimens. Metal Science and Heat Treatment. 2011, vol. 53, no. 11-12, pp. 611–617.

41. Shlyakman B.M., Yampol’skii O.N., Ratushev D.V. A method for determining constant C in the Hollomon parameter. Metal Science and Heat Treatment. 2011, vol. 52, no. 9-10, pp. 451–453.

42. Mel’nichenko A.S. Statisticheskii analiz v metallurgii i materialovedenii [Statistical analysis in metallurgy and materials science]. Moscow: ID MISiS, 2009, 268 p. (In Russ.).