Abstract
The constitutive flow behavior of austenitic stainless steel types AISI 304L, 316L, and 304 in the temperature range of 873 K (600 °C) to 1473 K (1200 °C) and strain-rate range of 0.001 s−1–100 s−1 has been evaluated with a view to establishing processing-microstructure-property relationships during hot working. The technique adopted for the study of constitutive behavior is through establishing processing maps and instability maps, and interpreting them on the basis of dynamic materials model (DMM). The processing maps for 304L have revealed a domain of dynamic recrystallization (DRX) occurring at 1423 K (1150 °C) at 0.1 s−1, which is the optimum condition for hot working of this material. The processing maps of 304 predict DRX domain at 1373 K (1100 °C) and 0.1 s−1. Stainless steel type 316L undergoes DRX at 1523 K (1250 °C) and 0.05 s−1. At 1173 K (900 °C) and 0.001 s−1 this material undergoes dynamic recovery (DRY). In the temperature and strain rate regimes other than DRX and DRY domains, austenitic stainless steels exhibit flow localization. Large-scale experiments using rolling, forging, and extrusion processes were conducted with a view to validating the conclusions arrived at from the processing maps. The “safe” processing regime predicted by processing maps has been further refined using the values of apparent activation energy during deformation. The validity and the merit of this refining procedure have been demonstrated with an example of press forging trials on stainless steel 316L. The usefulness of this approach for manufacturing stainless steel tubes and hot rolled plates has been demonstrated.
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References
N.J. Neale: Tribology Handbook, Butterworths, London, UK, 1983, p. 1.
D.T. Liewellyn and J.D. Murry: “Cold Worked Stainless Steels,” Special Report 86, Iron and Steel Institute, London, 1964, 197.
D.T. Liewellyn and V.J. McNeely: “Metallurgical Development in High Alloy Steels,” 1972, 49(1) p. 17.
W. Shichun: “Warm Forging of Stainless Steels,” J. Mech. Technol., 1982, 6, p. 333.
S. Venkadesan: “Warm Working of Austenitic Stainless Steels,” M.S. Thesis, IIT Madras, India, 1982.
W. Roberts: “Dynamic Changes that Occur During Hot Working and Their Significance Regarding Microstructural Development and Hot Workability” in Deformation, Processing and Structure, George Krauses, ed., ASM, Metals Park, OH, 1984, pp. 109–84.
M.C. Mataya, E.L. Brown, and M.P. Raendeau: “Effect of Hot Working on Structure and Strength of Type 304L Austenitic Stainless Steel,” Metall. Trans. A., 1990, 21A, p. 1969.
S.K. Mehra, S.M. Rao, and N. Swaminathan: “Development of Thick Walled 304L Stainless Steel Seamless Tubes for Reactor Use,” Trans. Indian Inst. Metals., 1987, 40(1), p. 71.
S. Venugopal, M. Vasudevan, Sridhar Venugopal, P.V. Sivaprasad, S.K. Jha, P. Pandey, S.L. Mannan and Y.V.R.K. Prasad: “Industrial Validation of Processing Maps of Stainless Steel 304L Using Hot Rolling, Forging and Extrusion,” J. Mater. Sci. and Technol., 1996, 12, pp. 955–62.
A.K. Gupta, K.E. Hughes, and C.M. Sellars: “Glass Lubricated Hot Extrusion of Stainless Steel,” Met. Technol., 1980, 7, p. 323.
K. Laue and H. Stenger: Extrusion: Processes, Machinery, Tooling, ASM, Metals Park, OH, 1981, p. 1.
S. Venugopal, S.L. Mannan, and Y.V.R.K. Prasad: “Influence of Strain-Rate and State-of-Stress on the Formation of Ferrite in Stainless Steel Type AISI 304 During Hot Working,” Materials Letters, 1995, 26, pp. 161–65.
F.B. Pickering: “Physical Metallurgy of Stainless Steel Developments,” Int. Met. Rev., Review No. 211, Dec. 1976, p. 227.
B. Ahlblom and R. Sandstrom: “Hot Workability of Stainless Steels: Influence of Deformation Parameters, Microstructural Components, and Restoration Processes,” Int. Met. Rev., Review No. 1, 1982, p. 1.
M.C. Mataya and G. Krauss: “A Test to Evaluate Flow Localization During Forging,” J. Appl. Metal Working, 1981, 2(1), p. 28.
M.K. Malik: “Extrusion Principles and Applications to Steel” in Proc. Intensive Course on Technology of Metal Forming, ASM-Indian Chapter and IIM-Bombay Chapter, Bombay, Maharashtra, India, 26–28 Feb., 1982, p. 31.
C. Rossard and P. Blain: “Simulation by Torsion of Hot Rolling Conditions to Determine Their Influence on Steel,” Revue de Metallurgie, 1965, 62, pp. 881–90.
W.J. McG Tegart: “Ductility,” ASM, Metals Park, Ohio, 1968, pp. 133–77.
H.J. McQueen and J.J. Jonas: “Recovery and Recrystallization During High Temperature Deformation” in Treatise on Materials Science and Technology, Vol. 6, Plastic Deformation of Materials, Academic Press Inc., New York, NY, 1975, pp. 394–493.
N.D. Ryan and H.J. McQueen: “Effects of Alloying Upon the Hot Workability of Carbon, Microalloyed, Tool, and Austenitic Stainless Steels” and “Mean Pass Flow Stresses and Interpass Softening in Multistage Processing of Carbon-, HLSA-, Tool- and -γ Stainless Steels,” J. Mech. Working Technol., 1986, 12, pp. 279–96 and 323–49.
C.M. Sellars: “Computer Modelling of Hot Working Processes,” Mater. Sci. Technol., 1985, 1, p. 325.
H.L. Gegel, J.C. Malas, W.G. Frazier, and S. Venugopal: “Optimal Design of Thermomechanical Processes,” in “Hand Book of Workability and Process Design,” ed. G.E. Dieter, H.A. Kuhn and S.L. Semiatin, ASM, Materials Park, OH, 2003, pp. 337–45.
S. Venugopal and Baldev Raj: “A Holistic Approach to Thermomechanical Processing of Alloys,” Sadhana, 2003, 28, pp. 833–57.
Y.V.R.K. Prasad, H.L. Gegel, S.M. Doraivelu, J.C. Malas, J.T. Morgan, K.A. Lark, and D.R. Barker: “Modeling of Dynamic Material Behavior in Hot Deformation: Forging of Ti-6242,” Metall. Trans. A, 1984, 15A, p. 1883.
Kalyan Kumar: “Criteria for Predicting Metallurgical Instabilities in Processing,” M.Sc., Thesis, Indian Institute of Science, Bangalore, India, 1987.
N.D. Ryan and H.J. McQueen: “Dynamic Softening Mechanisms in 304 Stainless Steels,” Can. Metall. Quarterly, 1990, 29, pp. 147–62.
S. Venugopal: “Optimization of Workability and Control of Microstructure in Deformation Processing of Austenitic Stainless Steels: Development and Application of Processing Maps for Stainless Steels Type AISI 304 and 316L,” Ph.D. Thesis, University of Madras, India, 1993.
P.V. Sivaprasad, S.L. Mannan, Y.V.R.K. Prasad, and R.C. Chaturvedi: “Identification of Processing Parameters for Fe-15Cr-2.2Mo-15Ni-0.3Ti Austenitic Stainless Steel Using Processing Maps,” Mater. Sci. Technol., 2001, 17, pp. 545–50.
S.L. Semiatin and G.D. Lagoti: “Deformation and Unstable Flow in Hot Forging of Ti-6Al-2Sn-4Zr-2Mo-0.1Si” and “Deformation and Unstable Flow in Hot Torsion of Ti-6Al-2Sn-4Zr-2Mo-0.1Si,” Metall. Trans. A, 1981, 12A, pp. 1705–17 and 1719–28.
P. Rodriguez: “Serrated Plastic Flow,” Bull. Mater. Sci., 1984, 6, pp. 653–63.
J.C. Malas and V. Seetharaman: “Using Materials Behavior Models to Develop Process Control Strategies,” J. Metals, 1992, 44, p. 8.
H.L. Gegel: private communication, 1998.
S. Venugopal, J.C. Malas, E.A. Medina, W.G. Frazier, S. Medeiros, W.M. Mullins, and R. Srinivasan: “Optimization of Microstructure During Deformation Processing Using Control Theory Principles,” Scripta Mater., 1997, 36, pp. 347–53.
K.E. Kirk: Optimal Control Theory, Prentice-Hall, Englewood Cliffs, NJ, 1970, p. 1.
G.F. Vander Vooret: Metallography, Principles and Practice, ASM International, Metal Park, OH, 1989, p. 1.
W.M. Mullins, R.D. Irwin, J.C. Malas, and S. Venugopal: “Examination on the Use of Acoustic Emission for Monitoring Metal Forging Processes: A Study Using Simulation Technique,” Scripta Mater., 1997, 36, pp. 967–74.
J.C. Malas: unpublished research, 1997.
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Venugopal, S., Sivaprasad, P.V. A journey with prasad’s processing maps. J. of Materi Eng and Perform 12, 674–686 (2003). https://doi.org/10.1361/105994903322692475
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DOI: https://doi.org/10.1361/105994903322692475