MODELO FÍSICO DA DEFORMAÇÃO E ENCRUAMENTO DO AÇO TWIP COM ALTO TEOR DE MANGANÊS E BAIXO CARBONO
PHYSICAL MODEL OF DEFORMATION AND WORK HARDENING OF HIGH MANGANEESE AND LOW CARBON TWIP STEEL
Spindola, Mirelle Oliveira; Gonzalez, Berenice Mendonça; Santos, Dagoberto Brandão
http://dx.doi.org/10.4322/tmm.00604012
Tecnol. Metal. Mater. Min., vol.6, n4, p.252-256, 2010
Resumo
A pesquisa por aços que combinem altos valores de resistência mecânica e conformabilidade, além de um baixo peso específico, é uma constante na indústria siderúrgica atual. É neste contexto que surge o aço alto Mn, Si e Al capaz de apresentar o efeito TWIP (TWinning Induced Plasticity) devido à baixa energia de falha de empilhamento na estrutura cristalina deste material. No trabalho atual desenvolve-se um modelo físico do encruamento de um aço C-0,06; Mn-25; Al-3; Si-2; Ni-1, apresentando o efeito TWIP, que foi inicialmente laminado a quente, a frio e recozido em temperaturas entre 600°C e 850°C. A fração volumétrica e o tamanho de grão recristalizado foram medidos através de microscopia óptica e eletrônica de varredura (MEV). Para tal modelo foram utilizados resultados de ensaios de tração do material nas várias condições de recozimento. Um modelo considerando a liga policristalina e baseado no comportamento mecânico do aço sob carregamento em tração foi aplicado. Foram utilizadas equações constitutivas formuladas a partir da teoria da plasticidade. Os resultados do modelo mostraram boa compatibilidade com a curva de fluxo obtida no ensaio de tração.
Palavras-chave
Efeito TWIP, Recozimento, Modelagem matemática, Simulação
Abstract
The new concepts for building automotive structures with impact resistance, formability, and low specific weight lead to increase in the research for materials with high strength and toughness, combined with low density. The TWIP steel (Twinning Induced Plasticity) can meet these needs and therefore it is essential its development. The material of this work, 0.06C-25Mn-3Al-2Si-1Ni steel, with TWIP effect, was hot and cold rolled and then annealed at temperatures between 600°C and 850°C. The microstructural examination was focused in the recrystallization during annealing for different temperatures through optical and scanning electron microscopy (SEM). For mechanical evaluation tensile tests were performed. A polycrystalline model, based on micromechanics and working hardening theory, developed by Bouaziz et al., to predict the behavior of TWIP steels under tensile tests was applied to current steel. The results from the model are in good agreement.
Keywords
TWIP effect, Annealing, Modeling, Simulation
Referências
1 FROMMEYER, G.; BRÜX, U.; NEUMANN, P. Supra-ductile and high-strength manganese-TRIP/TWIP steels for high energy
absorption purposes. ISIJ International, v. 43, n. 3, p. 438-46, Mar. 2003.
2 GRASSEL, O. et al. High strength Fe-Mn-(Al,Si) TRIP/TWIP Steels development – properties – application. International Journal of Plasticity, v. 16, n. 10-11, p. 1391-409, 2000.
3 VERCAMMEN, S. et al. Cold rolling behavior of an austenitic Fe–30Mn–3Al–3Si TWIP-steel: the importance of deformation twinning. Acta Materialia, v. 52, n. 7, p. 2005-12, Apr. 2004.
4 SCOTT, C. et al. The development of a new Fe-Mn-C austenitic steel for automotive applications. Revue de Metallurgie, v. 103, n. 6, p. 293-302, June 2006.
5 KIM, Y. G. et al. Development of new austenitic Fe-Mn-Al-C steels for automotive applications. Key Engineering Materials, v. 84-85, p. 461-472, 1993.
6 MECKING, H.; KOCKS, U. F. Kinetics of flow and strain-hardening. Acta Metallurgica, v. 29, n. 11, p. 1865-75, Nov. 1981.
7 REMY, L. Kinectics of F. C. C. deformation twinning and its relationship to stress-strain behaviour. Acta Metallurgica, v. 26, n. 3, p. 443-51, Mar. 1977.
8 OLSON, G.B.; COHEN, M. Kinectics of strain-induced martensite nucleation. Metallurgical Transactions A, v. 6A, n. 4, p. 791-795, April 1975.
9 BOUAZIZ, O.; GUELTON, N. Modeling of TWIP Effect on the work-hardening. Materials Science Engineering A, v. 319-321, p. 246-9, Dec., 2001.
10 ALLAIN, S.; CHATEU, J. P.; BOUAZIZ, O. A physical model of twinning-induced plasticity effect in high manganese austenitic steel. Materials Science Engineering A, v. 387-9, p. 143-7, Dec. 2004.
11 DUARTE, D. M.; RIBEIRO, E. A. S.; SANTOS, D. B. Comportamento mecânico do aço alto Mn e baixo C laminado a frio e recozido apresentando efeito TWIP. In: CONGRESSO ANUAL DA ABM, 64., 2009, Belo Horizonte, MG. Anais... São Paulo: ABM, 2009. 10 p.
12 BRACKE, L. et al. Recrystallization behavior of an austenitic high Mn steel. Materials Science Forum, v. 558-589, p. 137-142, Oct. 2007.
13 MI, Z. L. et al. Influence of cold rolling reduction on microstructure and mechanical properties of TWIP steel. Acta Metallurgica Sinica, v. 20, n. 6, p. 441-447, Dec. 2007.
14 DINI, G. et al. Improved tensile properties of partially recrystallized submicron grained TWIP steel. Materials Letters, v. 64, n. 1, p. 15-18, Jan. 2010.
2 GRASSEL, O. et al. High strength Fe-Mn-(Al,Si) TRIP/TWIP Steels development – properties – application. International Journal of Plasticity, v. 16, n. 10-11, p. 1391-409, 2000.
3 VERCAMMEN, S. et al. Cold rolling behavior of an austenitic Fe–30Mn–3Al–3Si TWIP-steel: the importance of deformation twinning. Acta Materialia, v. 52, n. 7, p. 2005-12, Apr. 2004.
4 SCOTT, C. et al. The development of a new Fe-Mn-C austenitic steel for automotive applications. Revue de Metallurgie, v. 103, n. 6, p. 293-302, June 2006.
5 KIM, Y. G. et al. Development of new austenitic Fe-Mn-Al-C steels for automotive applications. Key Engineering Materials, v. 84-85, p. 461-472, 1993.
6 MECKING, H.; KOCKS, U. F. Kinetics of flow and strain-hardening. Acta Metallurgica, v. 29, n. 11, p. 1865-75, Nov. 1981.
7 REMY, L. Kinectics of F. C. C. deformation twinning and its relationship to stress-strain behaviour. Acta Metallurgica, v. 26, n. 3, p. 443-51, Mar. 1977.
8 OLSON, G.B.; COHEN, M. Kinectics of strain-induced martensite nucleation. Metallurgical Transactions A, v. 6A, n. 4, p. 791-795, April 1975.
9 BOUAZIZ, O.; GUELTON, N. Modeling of TWIP Effect on the work-hardening. Materials Science Engineering A, v. 319-321, p. 246-9, Dec., 2001.
10 ALLAIN, S.; CHATEU, J. P.; BOUAZIZ, O. A physical model of twinning-induced plasticity effect in high manganese austenitic steel. Materials Science Engineering A, v. 387-9, p. 143-7, Dec. 2004.
11 DUARTE, D. M.; RIBEIRO, E. A. S.; SANTOS, D. B. Comportamento mecânico do aço alto Mn e baixo C laminado a frio e recozido apresentando efeito TWIP. In: CONGRESSO ANUAL DA ABM, 64., 2009, Belo Horizonte, MG. Anais... São Paulo: ABM, 2009. 10 p.
12 BRACKE, L. et al. Recrystallization behavior of an austenitic high Mn steel. Materials Science Forum, v. 558-589, p. 137-142, Oct. 2007.
13 MI, Z. L. et al. Influence of cold rolling reduction on microstructure and mechanical properties of TWIP steel. Acta Metallurgica Sinica, v. 20, n. 6, p. 441-447, Dec. 2007.
14 DINI, G. et al. Improved tensile properties of partially recrystallized submicron grained TWIP steel. Materials Letters, v. 64, n. 1, p. 15-18, Jan. 2010.
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