Super Plasticity of /α Duplex Stainless Steels

Document Type: Persian

Authors

1 Assistant Professor, Young Researchers and Elite Club, Islamic Azad University, Khomeinishahr Branch, Isfahan/Khomeinishahr, Iran

2 MSc Student, Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Isfahan, Iran.

Abstract

In this paper the studies of the two-phase super Plasticity stainless steels is studied. The aim of this study obtained the suitable criteria to thermo-mechanical treatment condition for decrease the microstructure (grain size) and super plasticity property in two-phase stainless steels. Also here we want to show the appropriate ranges of temperature and strain rate used in the process super plasticity to obtain maximum elongation for this kind of steel. The results showed that by using thermo-mechanical treatment that consists of dissolving, rolling and annealing, the grain size can be achieved to 0.5-4 μm.
The maximum elongation is achieved 1000% in the temperature range 800-1000˚C and strain rate is achieved 0.01-0.1 s-1. Under these conditions, the sensitivity coefficient of strain rate is around 0.6

[1] Matsushita, M., Suko, T., Ohfuji, H., Ogiyama, H., Analysis Of The Texture Of Superplastic Carburized Duplex Stainless Alloy, Materials Chemistry and Physics, vol. 114, 2009,  pp. 522-524.

[2] Matsushita, M., Ogiyama, H., Diffusion of Boron on superplastic duplex stainless Steel,  Journal of Phase Equilibria And Diffusion, vol. 31, No.1, 2001, pp. 2-5.

[3] Junior, A.M.J., Reis, G.S., Balancin, O., Influence of the microstructure on the plastic behavior of duplex stainless steels, Materials Science and Engineering A, In Press, 2010, Accepted Manuscript.

[4] Jimenez, J.A., Frommeyer, G., Carsi, M., Ruano, O.A., Superplastic properties of A δ/g stainless steel, Materials Science And Engineering A, vol. 307, 2001, pp. 134-142.

[5] Han, Y.S., Hong, S.H., Microstructural Changes During Superplastic Deformation Of Fe-24Cr-7Ni-3Mo-0.14N Duplex Stainless Steel, Materials Science And Engineering A, vol. 266, 1998, pp. 276-284.

[6] Sagradi, M., Sagradi, D.P., Medrano, R.E., The Effect of The Microstructure on The Superplasticity of A Duplex Stainless Steel, Acta Materialia, vol. 46, No. 11, 1998, pp. 3857-3862.

[7] Kassner, M.E., Fundamentals of Creep In Metals And Alloys, Elsevier, 2009.

[8] Maehara, Y., Ohmori, Y., Microstructural Change during Superplastic Deformation of δ-Ferrite/Austenite Duplex Stainless Steel, Metallurgical Transactions A, vol. 18A, 1987, pp. 663-672.

[9] Osada, K., Uekoh, S., Ebato, K., Superplasticity Of As Rolled Duplex Stainless Steel, Transactions ISI J, vol. 27, 1987, pp. 713-718.

[10] Maehara, Y., High Strain Rate Superplasticity Of A 25 Wt Pct Cr-7 Wt Pct Ni-3 Wt Pct Mo-0.14 Wt Pct N Duplex Stainless Steel, Metallurgical Transactions A, vol. 22A, 1991, pp. 1083-1091.

[11] Patankar, S.N., Lim, C.T., Tan, M.J., Superplastic Forming Of Duplex Stainless Steel, Metallurgical And Materials Transactions A, vol. 31A, 2000, pp. 2394-2396.

[12] Pulino-Sagradi, D., Nazar, A.M.M., Ammann, J.J., Medrano, R.E., Effect of Temperature And Strain Rate On Cavitation In A Superplastic Duplex Stainless Steel, Acta Materialia, vol. 45, No. 11, 1997, pp. 4663-4666.

[13] Maki, T., Furuhara, T., Tsuzaki, K., Microstructure Development By Thermo-mechanical Processing In Duplex Stainless Steel, ISI J International, vol. 41, 2001, pp. 571-579.

[14] Miyamoto, H., Miamaki, T., Hashimoto, S., Superplastic Deformation of Micro-Specimens of Duplex Stainless Steel, Materials Science and Engineering A, vol. 319-321, 2001, pp. 779-783.

[15] Han, Y.S., Hong, S.H., Phenomena and Mechanism on Super-plasticity of Duplex Stainless Steels, Metals And Materials, vol. 6, No. 2, 2000, pp. 161-167.

[16] Maehara Y., Superplastic Deformation of Duplex Stainless Steel, United States Patent, 1987, pp. 4637841.