Study of Texture and Warm Flow Stress of a Microalloyed Steel Due to Static Softening During Hot Deformation

Document Type : Original Articles

Authors

• Mostafa Mansourinejad ¹
• Bahman Mirzakhani ²

¹ Islamic Azad University, Dezful Branch

² Arak University

10.22067/ma.v0i29.63535

Abstract

In this paper, the influences of metallurgical phenomena and texture in addition to the thermomechanical parameters on the warm flow stress of austenite in a gas line-pipe microalloyed steel have been investigated. Warm compression tests were carried out in the temperature range of 850 to 950˚C under various amounts of strain, strain rates and holding times. The microstructure and texture of the samples were then investigated by scanning electron microscopy and electron back scatter diffraction technique. The results indicated that deformation temperature and strain via strain induce precipitation of microalloying elements during annealing impose the fraction of recrystallization in the material.

Keywords

• Static Softening
• Austenite
• Microalloyed Steel
• Stress relaxation

---

References

1. Hodgson P.D., Barnett M.R., "The Thermomechanical processing of steels-current and future trends", Proceedings of the 8th International Conference on Metal Forming, Krakow, Poland, pp. 21-28, (2000).
2. Humphreys F.J., Hatherly M., "Recrystallization and related annealing phenomena", Second ed., Oxford, Elsevier, (2004).
3. Sakai T., Jonas J.J., "Overview no. 35 dynamic recrystallization: mechanical and microstructural considerations", Acta Metallurgica, Vol. 32, No.2, pp.189-209, (1984).
4. McQueen H.J., "Initiating nucleation of dynamic recrystallization, primarily in polycrystals", Materials Science and Engineering, Vol. 101A, pp. 149-160, (1988).
5. Titto K., Fitzsimons G., Deardo A.J., "The effect of dynamic precipitation and recrystallization on the hot flow behavior of a Nb-V microalloyed steel", Acta Metallurgica, Vol. 31, No. 8, pp. 1159-1168, (1983).
6. Sellars C.M., Davies G.J., "Hot working and forming processes", London, Metals Society, (1980).
7. Gomez M., Medina S.F., Quispe A., Valles P., "Static recrystallization and induced precipitation in a low Nb microalloyed steel", ISIJ International, Vol. 42, No. 4, pp. 423–431, (2002).
8. Honeycombe R.W.K., "The plastic deformation of metals", Second ed., Edward Arnold, Maryland, (1984).
9. Kwon O., DeArdo A.J., "Interactions between recrystallization and precipitation in hot-deformed microalloyed steels", Acta Metallurgical and Materialia, Vol. 39, No. 4, pp. 529-538, (1991).
10. Andrade H.L., Akben M.G., Jonas J.J., "Effect of molybdenum, niobium, and vanadium on static recovery and recrystallization and solute strengthening in microalloyed steels", Metallurgical Transaction A., Vol. 14, pp. 1967-1977, (1983).
11. Medina S.F., Mancilla J.E., "Static steels recrystallization at temperatures modeling below of the hot deformed microalloyed critical temperature", ISIJ International, Vol. 36, No. 8, pp. 1070-1083, (1996).
12. Medina S.F., Mancilla J.E.,"Determination of static recrystallization critical temperature of austenite in microalloyed steels", ISIJ International, Vol. 33, No. 12, pp. 1257-1264, (1993).
13. Medina S.F., Quispe A., "Improved model for static recrystallization kinetics of hot deformed austenite in low alloy and Nb/V microalloyed steels", ISIJ International, Vol. 41, No. 7, pp. 774–781, (2001).
14. Lee K.J., "Recrystallization and precipitation interaction in Nb containing steels", Scripta Materialia, Vol. 40, No. 7, pp. 837-843, (1999).
15. Mirzakhani B., Arabi H., Salehi M.T.S., Seyedein H., Aboutalebi M.R., Khoddam S., Sietsma J.,"Computer aided optimization of specimen geometry of hot torsion test to minimize microstructure non-homogeneity and temperature gradient before deformation", Iranian Journal of Materials Science & Engineering, Vol. 6, No. 3, pp. 35-43, (2009).