Prediction of microstructure evolution during multi-stand shape rolling of nickel-base superalloys
- 2.6k Downloads
In this paper, a comprehensive numerical approach to predict the microstructure of nickel-base superalloys during multi-stand shape rolling is presented. This approach takes into account the severe deformation that occurs during each pass and also the possible reheating between passes. In predicting the grain size at the end of the rolling process, microstructural events such as dynamic recrystallization (DRX), metadynamic recrystallization (MDRX), and static grain growth are captured at every deformation step for superalloys. Empirical relationships between the average grain size from various microstructural processes and the macroscopic variables such as temperature (T) and effective strain () and strain rate () form the basis for the current work. These empirical relationships are based on Avrami equations. The macroscopic variables are calculated using a finite element analysis package wherein the material being rolled is modeled as a non-Newtonian fluid with viscosity that depends on the effective strain rate, strain, and temperature. A two-dimensional transient thermal analysis is carried out between passes that can capture the MDRX and/or static grain growth during the microstructural evolution. The presented microstructure prediction algorithm continuously updates two families of grains, namely, the recrystallized family and strained family at the start of deformation in any given pass. In addition, the algorithm calculates various subgroups within these two families at every deformation step within a pass. As the material undergoes deformation between the rolls, recrystallization equations are invoked depending on critical strain and strain rate conditions that are characteristics of superalloys. This approach predicts the microstructural evolution based on recrystallization kinetics and static grain growth only. The methodology was successfully applied to predict the microstructure evolution during the multi-pass rolling of nickel-base superalloys. The predicted results for Alloy 718 for a 4-stand rolling followed by air cooling and for a 16-stand rolling followed by a combination of air and water cooling are also compared with experimental observations.
KeywordsMulti-stand Multi-pass Shape rolling Microstructure Modeling Nickel-base Superalloys
Financial support for this research work is provided by ATI Allvac, Monroe, NC. The authors express gratitude towards Drs. Minisandram and Thomas from ATI Allvac for their valuable inputs on Alloy 718 and multi-stand rolling simulation.
- 1.Minisandram RS, Thompson EG, Forbes Jones RM, Stedje-Larsen R (2001) Numerical simulation of a multi-stand rolling mill. In: Mori K (ed)Proceedings of the 7th international conference on numerical methods in industrial forming processes - NUMIFORM 2001, Toyohashi, Japan, 18–21 June 2001.. Swets & Zeitlinger B.V., Lisse.Google Scholar
- 2.Subramanian K, Minisandram RS, Cherukuri HP (2007) Mesh re-zoning in multi-stand rolling. In: César de Sá JMA (ed)Proceedings of the 9th international conference on numerical methods in industrial forming processes - NUMIFORM 2007, Porto, Portugal, 17–21 June 2007.. American Institute of Physics (API), College Park.Google Scholar
- 4.Thomas JP, Bauchet E, Dumont C, Montheillet F: EBSD Investigation and modelling of the microstructural evolutions of superalloy 718 during hot deformation. In Proceedings of Superalloys 2004. Edited by: Green KA. The Minerals, Metals & Materials Society (TMS), Warrendale; 2004:959–968.Google Scholar
- 5.Zienkiewicz O: Flow formulation for numerical solution of forming processes. In Numerical analysis of forming processes. Wiley, New York; 1984:1–69.Google Scholar
- 6.Humphreys FJ, Hatherly M: Recrystallization and related annealing phenomena. Elsevier, Oxford; 2004.Google Scholar
- 8.Huang D, Wu WT, Lambert D, Semiatin SL: Computer simulation of microstructure evolution during hot forging of waspaloy and nickel alloy 718. In Proceedings of symposium: microstructure modeling and prediction during thermomechanical processing, Indianapolis, November 4–8 2001. Edited by: Srinivasan R, Semiatin SL, Beaudoin A, Fox S, Jin Z. TMS, Warrendale; 2001:137–147.Google Scholar
- 9.Shen G (1994) Modeling microstructural development in the forging of waspaloy turbine engine disks. Dissertation, Ohio State University. Shen G (1994) Modeling microstructural development in the forging of waspaloy turbine engine disks. Dissertation, Ohio State University.Google Scholar
- 12.Shen G: Microstructure modeling in superalloy forging. In Cold and hot forging: fundamentals. Edited by: Altan T. ASM International, Novelty; 2005:247–255.Google Scholar
- 18.Kusiak J, Kuziak R, Wajda W, Kowalski B (1999) Finite-element modeling of forging of nickel based superalloys. In: Kanagy DL (ed)Proceedings of 41st Mechanical Working and Steel Processing Conference, Baltimore, Maryland, October 24–27 1999, 683–688.. Iron and Steel Society, London, vol. XXXVII.Google Scholar
- 24.Zhao D, Cheng C, Anbajagane R, Dong H, Suarez FS (1997) Three-dimensional computer simulation of alloy 718: Ingot breakdown by cogging. In: Loria EA (ed)Proceedings of the 4th International Symposium on Superalloys 718, 625, 706 and Various Derivatives, Pittsburgh, Pennsylvania, June, 15–18 1997, 163–172.. The Minerals, Metals & Materials Society (TMS), Warrendale.Google Scholar
- 25.Hirch J, Karhausen K, Kopp R (1994) Microstructural simulation during hot rolling of Al-Mg Alloys In: Proceedings of the 4th International Conference on Aluminium Alloys, Atlanta, Georgia, Georgia Institute of Technology, School of Materials Science & Engineering, 476–483, Atlanta.Google Scholar
- 31.Karhausen K, Kopp R, de Souza MM: Numerical simulation method for designing thermomechanical treatments, illustrated by bar rolling. Scandinavian J Metall 1991, 20(6):351–363.Google Scholar
- 34.Subramanian K (2009) Microstructure evolution during multi-stand rolling of nickel-base superalloy. Dissertation, University of North Carolina at Charlotte.Google Scholar
- 35.Guest RP, Tin S (2005) The dynamic and metadynamic recrystallisation of the in 718. In: Loria EA (ed)Proceedings of the 6th international symposium on superalloys 718, 625, 706 and various derivatives, Pittsburgh PA, October 2–5 2005.. The Minerals, Metals & Materials Society (TMS), Warrendale.Google Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.