Hot compression deformation behavior of AISI 321 austenitic stainless steel

Abstract

The hot compression behavior of AISI 321 austenitic stainless steel was studied at the temperatures of 950–1100°C and the strain rates of 0.01–1 s⁻¹ using a Baehr DIL-805 deformation dilatometer. The hot deformation equations and the relationship between hot deformation parameters were obtained. It is found that strain rate and deformation temperature significantly influence the flow stress behavior of the steel. The work hardening rate and the peak value of flow stress increase with the decrease of deformation temperature and the increase of strain rate. In addition, the activation energy of deformation (Q) is calculated as 433.343 kJ/mol. The microstructural evolution during deformation indicates that, at the temperature of 950°C and the strain rate of 0.01 s⁻¹, small circle-like precipitates form along grain boundaries; but at the temperatures above 950°C, the dissolution of such precipitates occurs. Energy-dispersive X-ray analyses indicate that the precipitates are complex carbides of Cr, Fe, Mn, Ni, and Ti.

Keywords

austenitic stainless steel / deformation / constitutive equations / microstructural evolution / activation energy

References

[1] Peckner D, Bernstein IM. Handbook of Stainless Steels, 1977, New York, McGraw-Hill, 48.

[2] Chabaud-Reytier M, Allais L, Caes C, Dubuisson P, Pineau A. Mechanisms of stress relief cracking in titanium stabilised austenitic stainless steel. J. Nucl. Mater., 2003, 323, 123.

[3] Min KS, Kim KJ, Nam SW. Investigation of the effect of the types and densities of grain boundary carbides on grain boundary cavitation resistance of AISI 321 stainless steel under creep-fatigue interaction. J. Alloys Compd., 2004, 370, 223.

[4] Guan KS, Xu XD, Zhang YY, Wang ZW. Cracks and precipitate phases in 321 stainless steel weld of flue gas pipe. Eng. Failure Anal., 2005, 12, 623.

[5] Pardo A, Merino MC, Coy AE, Viejo F, Carboneras M, Arrabal R. Influence of Ti, C and N concentration on the intergranular corrosion behaviour of AISI 316Ti and 321 stainless steels. Acta Mater., 2007, 55, 2239.

[6] Zhang WH, Wu JL, Wen YH, Ye JJ, Li N. Characterization of different work hardening behavior in AISI 321 stainless steel and hadfield steel. J. Mater. Sci., 2010, 45, 3433.

[7] Guan KS, Xu XD, Xu H, Wang ZW. Effect of aging at 700°C on precipitation and toughness of AISI 321 and AISI 347 austenitic stainless steel welds. Nucl. Eng. Des., 2005, 235, 2485.

[8] de Sousa RC, Filho JC C, Tanaka AA, de Oliveira ACS, Ferreira WEI. Effects of solution heat treatment on grain growth and degree of sensitization of AISI 321 austenitic stainless steel. J. Mater. Sci., 2006, 41(8): 2381.

[9] Moura V, Kina AY, Tavares SSM, Lima LD, Mainier FB. Influence of stabilization heat treatments on microstructure, hardness and intergranular corrosion resistance of the AISI 321 stainless steel. J. Mater. Sci., 2008, 43, 536.

[10] Nair KD. Structure and strength during hot working of an austenitic steel. Metallography, 1971, 4, 375.

[11] Havela L, Kratochvíl P, Lukáč P, Smola B, á A S. Softening during and after the hot deformation of the AISI 321 steel with respect to practical applications. Czech. J. Phys. B, 1988, 38, 384.

[12] Poliak EI, Jonas JJ. Initiation of dynamic recrystallization in constant strain rate hot deformation. ISIJ Int., 2003, 43(5): 684.

[13] Herbertz R, Wiegels H. A method of performing the frictionless cylinder upsetting test for plotting stress-strain curves. Stahl Eisen., 1981, 101, 89.

[14] Mirzadeh H, Najafizadeh A, Moazeny M. Flow curve analysis of 17-4 PH stainless steel under hot compression test. Metall. Mater. Trans. A, 2009, 40, 2950.

[15] Ebrahimi R, Najafizadeh A. A new method for evaluation of friction in bulk metal forming. J. Mater. Process. Technol., 2004, 152, 136.

[16] Mirzadeh H, Najafizadeh A. Extrapolation of flow curves at hot working conditions. Mater. Sci. Eng. A, 2010, 527(7–8): 1856.

[17] Najafizadeh A, Jonas JJ. Predicting the critical stress for initiation of dynamic recrystallization. ISIJ Int., 2006, 46(11): 1679.

[18] Momeni A, Dehghani K, Keshmiri H, Ebrahimi GR. Hot deformation behavior and microstructural evolution of a superaustenitic stainless steel. Mater. Sci. Eng. A, 2010, 527, 1605.

[19] Zou DN, Han Y, Yan DN, Wang D, Zhang W, Fan GW. Hot workability of 00Cr13Ni5Mo2 supermartensitic stainless steel. Mater. Des., 2011, 32, 4443.

[20] Zener C, Hollom JH. Effect of strain rate upon plastic flow of steel. J. Appl. Phys., 1944, 15, 22.

[21] Cingara A, McQueen HJ. New method for determining sinh constitutive constants for high temperature deformation of 300 austenitic steels. J. Mater. Process. Technol., 1992, 36, 17.

[22] McQueen HJ, Ryan ND. Constitutive analysis in hot working. Mater. Sci. Eng. A, 2002, 322, 43.

[23] Lin YC, Chen MS, Zhong J. Constitutive modeling for elevated temperature flow behavior of 42CrMo steel. Comput. Mater. Sci., 2008, 42, 470.

[24] Mandal S, Rakesh V, Sivaprasad PV, Venugopal S, Kasiviswanathan KV. Constitutive equations to predict high temperature flow stress in a Ti-modified austenitic stainless steel. Mater. Sci. Eng. A, 2009, 500, 114.