کنترل ریزساختار و خواص مکانیکی فولاد زنگ نزن آستنیتی توسط بازگشت مارتنزیت کرنشی و تبلور مجدد آستنیت باقیمانده

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد دانشکده مهندسی متالورژی و مواد دانشکده فنی دانشگاه تهران.

2 استادیار دانشکده مهندسی متالورژی و مواد دانشکده فنی دانشگاه تهران.

چکیده

تحولات ریز ساختاری در حین عملیات آنیل فولاد زنگ نزن آستنیتی 304 پس از نورد سرد مورد ارزیابی قرار گرفت و مشخص شد که سه مرحله مجزا وجود دارد که شامل بازگشت مارتنزیت به آستنیت، تبلور مجدد آستنیت باقی مانده و رشد دانه می‌باشد. بازگشت مارتنزیت به آستنیت منجر به تولید ساختار فوق ریزدانه شد. با این وجود، تبلور مجدد آستنیت باقی مانده، تشکیل ساختار هم محور را به تاخیر انداخت و سبب شد که دانه های ریز آستنیت بازگشت یافته نیز رشد کنند و ریزساختاری با متوسط اندازه دانه بین 1 تا 2 میکرومتر به دست آمد. بررسی خواص مکانیکی نشان داد که بازگشت مارتنزیت به آستنیت و تولید ساختار ریزدانه منجر به افزایش چشمگیر استحکام نهایی به میزان 40 درصد می شود. همچنین ادامه آنیل برای انجام تبلور مجدد در آستنیت باقی مانده برای تولید ساختار هم محور نهایی منجر به کاهش استحکام و بهبود انعطاف پذیری می گردد. به این شکل می توان ریزساختار و خواص مکانیکی فولادهای زنگ نزن آستنیتی را تحت کنترل قرار داد.

کلیدواژه‌ها


عنوان مقاله [English]

Controlling the microstructure and mechanical properties of austenitic stainless steel by reversion of strain-induced martensite and recrystallization of retained austenite

نویسندگان [English]

  • Meysam Naghizadeh 1
  • H hmirzadeh 2
1 Master Student, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran,
2 Assistant Professor, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran,
چکیده [English]

Microstructural evolution during annealing of AISI 304 austenitic stainless steel following cold rolling was evaluated. It was revealed that three annealing stages are available: Reversion of martensite to austenite, recrystallization of the retained austenite, and grain growth. Reversion of martensite to austenite resulted to the development of an ultrafine grained microstructure. However, the recrystallization of the retained austenite postponed the formation of an equiaxed microstructure, during which, the fine austenite grains become coarser and a microstructure with average grain size between 1 and 2 µm was obtained. Evaluation of mechanical properties revealed that the reversion of martensite to austenite and the resultant grain refinement enhanced the tensile strength by 40%. Moreover, further annealing for the occurrence of the recrystallization in the retained austenite to obtain an equiaxed microstructure resulted in the decline of tensile strength and enhancement of ductility. In this way, it is possible to control the microstructure and mechanical properties of austenitic stainless steels.

کلیدواژه‌ها [English]

  • Strain-induced martensite
  • Martensite reversion
  • Retained austenite
  • Mechanical properties
1. K.H. Lo, C.H. Shek, and J.K.L. Lai, “Recent developments in stainless steels”, Mater. Sci. Eng. R, 2009, vol. 65, pp. 39–104.

2. H. Mirzadeh and A. Najafizadeh, “Correlation between processing parameters and strain-induced martensitic transformation in cold worked AISI 301 stainless steel”, Mater. Charact., 2008, vol. 59, pp. 1650–54.

3. M. Naghizadeh and H. Mirzadeh, “Microstructural evolutions during annealing of plastically deformed AISI 304 austenitic stainless steel: Martensite reversion, grain refinement, recrystallization, and grain growth”, Metal. Mater. Trans. A, 2016, vol. 47, pp. 4210–16.

4. H. Mirzadeh, J.M. Cabrera, A. Najafizadeh, and P.R. Calvillo, “EBSD study of a hot deformed austenitic stainless steel”, Mater. Sci. Eng. A, 2012, vol. 538, pp. 236–45.

5. F. Borgioli, E. Galvanetto, and T. Bacci, “Low temperature nitriding of AISI 300 and 200 series austenitic stainless steels”, Vacuum, 2016, vol. 127, pp. 51–60.

6. K. Spencer, J.D. Embury, K.T. Conlon, M. Ve´ron, and Y. Bre´chet, “Strengthening via the formation of strain-induced martensite in stainless steels”, Mater. Sci. Eng. A, 2004, vols. 387–389, pp. 873–81.

7. A. Vinogradov, I.S. Yasnikov, H. Matsuyama, M. Uchida, Y. Kaneko, and Y. Estrin, “Controlling strength and ductility: Dislocation-based model of necking instability and its verification for ultrafine grain 316L steel”, Acta Mater., 2016, vol. 106, pp. 295–303.

8. K. Tomimura, S. Takaki, S. Tanimoto, and Y. Tokunaga, “Optimal chemical composition in Fe-Cr-Ni alloys for ultra grain refining by reversion from deformation induced martensite”, ISIJ Int., 1991, vol. 31, pp. 721–27.

9. M. Shirdel, H. Mirzadeh, and M.H. Parsa, “Nano/ultrafine grained austenitic stainless steel through the formation and reversion of deformation-induced martensite: Mechanisms, microstructures, mechanical properties, and TRIP effect”, Mater. Charact., 2015, vol. 103, pp. 150–61.

10. A. Hedayati, A. Najafizadeh, A. Kermanpur, and F. Forouzan, “The effect of cold rolling regime on microstructure and mechanical properties of AISI 304L stainless steel”, J. Mater. Process. Technol., 2010, vol. 210,  pp. 1017–22.

11. F. Forouzan, A. Najafizadeh, A. Kermanpur, A. Hedayati, and R. Surkialiabad, “Production of nano/submicron grained AISI 304L stainless steel through the martensite reversion process”, Mater. Sci. Eng. A, 2010, vol. 527, pp. 7334–39.

12. S. Sabooni, F. Karimzadeh, M.H. Enayati, and A.H.W. Ngan, “The role of martensitic transformation on bimodal grain structure in ultrafine grained AISI 304L stainless steel”, Mater. Sci. Eng. A, 2015, vol. 636, pp. 221–30.

13. H. Jafarian, “Characteristics of nano/ultrafine-grained austenitic TRIP steel fabricated by accumulative roll bonding and subsequent annealing”, Mater. Charact., 2016, vol. 114, pp. 88–96.

14. J. Talonen, P. Nenonen, G. Pape, and H. Hänninen, “Effect of strain rate on the strain-induced γ→α′-martensite transformation and mechanical properties of austenitic stainless steels”, Metall. Mater. Trans. A, 2005, vol. 36, pp. 421–32.

15. A. Kisko, R.D.K. Misra, J. Talonen, and L.P. Karjalainen, “The influence of grain size on the strain-induced martensite formation in tensile straining of an austenitic 15Cr–9Mn–Ni–Cu stainless steel”, Mater. Sci. Eng. A, 2013, vol. 578, pp. 408–16.

16. A.S. Hamada, A.P. Kisko, P. Sahu, and L.P. Karjalainen, “Enhancement of mechanical properties of a TRIP-aided austenitic stainless steel by controlled reversion annealing”, Mater. Sci. Eng. A, 2015, vol. 628, pp. 154–59.

17. R.D.K. Misra, S. Nayak, S.A. Mali, J.S. Shah, M.C. Somani, and L.P. Karjalainen, “Microstructure and Deformation Behavior of Phase-Reversion- Induced Nanograined/Ultrafine-Grained Austenitic Stainless Steel”, Metall. Mater. Trans. A, 2009, vol. 40A, pp. 2498-509.

18. M. Shirdel, H. Mirzadeh, and M.H. Parsa, “Enhanced Mechanical Properties of Microalloyed Austenitic Stainless Steel Produced by Martensite Treatment”, Adv. Eng. Mater., 2015, vol. 17, pp. 1226-33.

19. M. Eskandari, A. Najafizadeh, A. Kermanpur, and M. Karimi, “Potential application of nanocrystalline 301 austenitic stainless steel in lightweight vehicle structures”, Mater. Des., 2009, vol. 30, pp. 3869–72.

20. B. Fultz and J. Howe: Transmission Electron Microscopy and Diffractometry of Materials, 3rd ed., Springer, Berlin, 2008.

21. A. Etienne, B. Radiguet, C. Genevois, J.M. Le Breton, R. Valiev, and P. Pareige, “Thermal stability of ultrafine-grained austenitic stainless steels”, Mater. Sci. Eng. A, 2010, vol. 527, pp. 5805–10.

22. G. B. Olson, M. Cohen, “Kinetics of strain-induced martensitic nucleation”, Metall. Mater. Trans. A, 1975, vol. 6, pp. 791–95.

23. K. Nohara, Y. Ono, N. Ohashi, “Composition and grain size dependence of strain induced martensitic transformation in metastable austenitic stainless steels”, J. Iron Steel Ins., 1977, vol. 63, pp. 772–78.

24. M. Shirdel, H. Mirzadeh, and M.H. Parsa, “Microstructural evolution during normal/abnormal grain growth in austenitic stainless steel”, Metall. Mater. Trans. A, 2014, vol. 45, pp. 5185-93.

25. M. Shirdel, H. Mirzadeh, and M.H. Parsa, “Abnormal grain growth in AISI 304L stainless steel”, Mater. Charact., 2014, vol. 97, pp. 11-17.