ANÁLISE NUMÉRICA E EXPERIMENTAL DAS TENSÕES RESIDUAIS GERADAS NA TÊMPERA DE UM CILINDRO DE AÇO AISI 4140
NUMERICAL AND EXPERIMENTAL ANALYSIS OF RESIDUAL STRESSES GENERATED DURING HARDENING OFAISI 4140 BAR
Echeverri, Edwan Anderson A.; Tschiptschin, André Paulo
http://dx.doi.org/10.4322/tmm.2012.026
Tecnol. Metal. Mater. Min., vol.9, n3, p.182-189, 2012
Resumo
O objetivo deste trabalho é analisar a distribuição das tensões residuais que resultam da combinação das variações volumétricas resultantes dos gradientes térmicos e das transformações de fase que ocorrem durante a têmpera de um cilindro de aço AISI/SAE 4140. O modelo matemático usado para este objetivo utiliza o software AC3 de modelagem de tratamentos térmicos (curvas de transformação, curvas de resfriamento e a microestrutura do material), para alimentar um modelo de elementos finitos, considerando acoplamento termomecânico e comportamento não linear elasto-plástico, para previsão de tensões residuais em cilindros de aço 4140 temperados. São apresentados, também, os resultados de observações metalográficas que confirmam, quantitativa e qualitativamente, as previsões do software AC3. A verificação do modelo numérico é efetuada por meio da medida das tensões residuais pela técnica de difração de raios X. A simulação numérica, por elementos finitos, evidencia a existência de tensões residuais de compressão, da ordem de 350 MPa, na região superficial após têmpera e indica de que as tensões mais significativas são as tangenciais.
Palavras-chave
Modelagem, Método de elementos finitos, Têmpera, Tensão residual
Abstract
The aim of this work is to analyze the distribution of residual stresses resulting from the combination of volumetric changes due to heat gradients and phase changes occurring during the quenching process of an AISI/SAE 4140 steel cylinder. The mathematical model used for this objective is the AC3 modeling software of thermal treatments (transformation curves, cooling curves and microstructure), whose results were input in an finite element model, considering thermal-mechanical coupling and non-linear elastic-plastic behavior, aiming the assessment of residual stresses in quenched 4140 steel cylinders. The observed microstructure confirms quantitatively and qualitatively the previsions of the AC3 Software. The results of the modeling are compared with the residual stresses measurements made using X-Ray diffraction techniques. The finite element numerical simulation shows the existence of 350 MPa compressive residual stresses in the surface region and indicates that the most significant stresses are tangential.
Keywords
Modeling, Finite element method, Quenching, Residual stress
Referências
1 ARIMOTO, K. et al. Preliminary study to identify criterion for quench crack prevention by computer simulation.
Transactions of Materials and Heat Treatment, v. 25, n. 5, p. 486-93, 2004.
2 ARIMOTO, K. et al. Explanation of the origin of distortion and residual stress in water quenched cylinders using computer simulation. Journal of ASTM International, v. 3, n. 5, May 2006. Disponivel em:. Acesso em: 31 jan. 2011. http://dx.doi.org/10.1520/
JAI14204
3 EHLERS, M.; MÜLLER, H.; LÖHE, D. Simulation of stresses, residual stresses, and distortion in stepped cylinders of AlSl 4140 due to martensitical hardening by immersion cooling. Journal de Physique. IV France, v. 9, p. 333-40, 1999. http://dx.doi.org/10.1051/jp4:1999934
4 DENIS, S. et al. Modeling of phase transformation kinetics in steels and coupling with heat treatment residual stress predictions. Journal de Physique. IV France, v. 9, p. 223-332, 1999. http://dx.doi.org/10.1051/jp4:1999933
5 DENIS, S. et al. Phase transformation and generation of heat treatment residual stress in metallic alloys. Materials Science Forum, v. 347-9, p. 184-98, 2000. http://dx.doi.org/10.4028/www.scientific.net/MSF.347-349.184
6 DENIS, S. et al. Prediction of residual stress and distortion of ferrous and non-ferrous metals: current status and future developments. Journal of Materials Engineering and Performance, v. 11, n. 1, p. 92-102, 2002. http://dx.doi. org/10.1007/s11665-002-0014-2
7 ALVES, G. Caracterização microestrutural de um aço médio carbono e baixa liga (com estrutura bainítica/martensítica) via microscopia óptica. 2008. 161 f. Dissertação (Mestrado em Engenharia na área de Projetos e Materiais) – Faculdade de Engenharia de Guaratinguetá, 2008.
8 Image J (para Windows e Linux). Disponível em: . Acesso em fevereiro de 2011.
9 ASTM INTERNATIONAL. ASTM E 562-02. Standard test method for determining volume fraction by systematic manual point count. West Conshohocken, 2002.
10 ASTM INTERNATIONAL. ASTM E 1426-98. Standard test method for determining the effective elastic parameter for X-ray diffraction measurements of residual stress. West Conshohocken, 2009.
11 MARATHON MONITORS. AC3 heat treatment software operating manual. Ohio, 1994.
12 SEDIGHI, M., SALEK, M. Modeling and experimental study of quenching process for AISI 4340 aeronautical steel under different cooling conditions. Transactions the Canadian Society for Mechanical Engineering, v. 32, n. 1, p. 1-8, 2008.
13 ECKEL, B. Thinking in Java. 4. ed. New York: Prentice Hall, 2006.
14 NORTHOVER, S.; WILSON, M. SWT: the standard widget toolkit. Reading: Addison-Wesley Professional, 2004. v. 1.
15 BHADESHIA, H. K. D. H. Material factors. In: TOTTEN, G.; HOWES, M.; INOUE, T., eds. Handbook of residual stress and deformation of steel. Materials Park: ASM International, 2002.
16 SCHRÖDER, R. Influences on development of thermal and residual stresses in quenched steel cylinders of different dimensions. Materials Science and Technology, v. 1, n. 10, p. 754-64, Oct. 1985. http://dx.doi. org/10.1179/026708385790124134
17 PIETZSCH, R. et al. Simulation of the distortion of long steel profiles during cooling. Journal of Applied Mechanics, v. 74, n. 3, p. 427-37, May 2007. http://dx.doi.org/10.1115/1.2338050
18 TOTTEN, G. E.; HOWES, M.A. Steel heat treatment handbook. New York: Marcel Deker, 1997.
19 LI, H.; ZHAO, G.; HE, L. Finite element method based simulation of stress-strain field in the quenching process. Materials Science and Engineering A, v. 478, n. 1-2, p. 276-90, Apr. 2008. http://dx.doi.org/10.1016/j. msea.2007.05.101
20 ROHDE, J.; JEPPSSON, A. Literature review of heat treatment simulations with respect to phase transformation, residual stresses and distortion. Scandinavian Journal of Metallurgy, v. 29, n.2, p. 47-62, Apr. 2000. http://dx.doi. org/10.1034/j.1600-0692.2000.d01-6.x
2 ARIMOTO, K. et al. Explanation of the origin of distortion and residual stress in water quenched cylinders using computer simulation. Journal of ASTM International, v. 3, n. 5, May 2006. Disponivel em:
3 EHLERS, M.; MÜLLER, H.; LÖHE, D. Simulation of stresses, residual stresses, and distortion in stepped cylinders of AlSl 4140 due to martensitical hardening by immersion cooling. Journal de Physique. IV France, v. 9, p. 333-40, 1999. http://dx.doi.org/10.1051/jp4:1999934
4 DENIS, S. et al. Modeling of phase transformation kinetics in steels and coupling with heat treatment residual stress predictions. Journal de Physique. IV France, v. 9, p. 223-332, 1999. http://dx.doi.org/10.1051/jp4:1999933
5 DENIS, S. et al. Phase transformation and generation of heat treatment residual stress in metallic alloys. Materials Science Forum, v. 347-9, p. 184-98, 2000. http://dx.doi.org/10.4028/www.scientific.net/MSF.347-349.184
6 DENIS, S. et al. Prediction of residual stress and distortion of ferrous and non-ferrous metals: current status and future developments. Journal of Materials Engineering and Performance, v. 11, n. 1, p. 92-102, 2002. http://dx.doi. org/10.1007/s11665-002-0014-2
7 ALVES, G. Caracterização microestrutural de um aço médio carbono e baixa liga (com estrutura bainítica/martensítica) via microscopia óptica. 2008. 161 f. Dissertação (Mestrado em Engenharia na área de Projetos e Materiais) – Faculdade de Engenharia de Guaratinguetá, 2008.
8 Image J (para Windows e Linux). Disponível em:
9 ASTM INTERNATIONAL. ASTM E 562-02. Standard test method for determining volume fraction by systematic manual point count. West Conshohocken, 2002.
10 ASTM INTERNATIONAL. ASTM E 1426-98. Standard test method for determining the effective elastic parameter for X-ray diffraction measurements of residual stress. West Conshohocken, 2009.
11 MARATHON MONITORS. AC3 heat treatment software operating manual. Ohio, 1994.
12 SEDIGHI, M., SALEK, M. Modeling and experimental study of quenching process for AISI 4340 aeronautical steel under different cooling conditions. Transactions the Canadian Society for Mechanical Engineering, v. 32, n. 1, p. 1-8, 2008.
13 ECKEL, B. Thinking in Java. 4. ed. New York: Prentice Hall, 2006.
14 NORTHOVER, S.; WILSON, M. SWT: the standard widget toolkit. Reading: Addison-Wesley Professional, 2004. v. 1.
15 BHADESHIA, H. K. D. H. Material factors. In: TOTTEN, G.; HOWES, M.; INOUE, T., eds. Handbook of residual stress and deformation of steel. Materials Park: ASM International, 2002.
16 SCHRÖDER, R. Influences on development of thermal and residual stresses in quenched steel cylinders of different dimensions. Materials Science and Technology, v. 1, n. 10, p. 754-64, Oct. 1985. http://dx.doi. org/10.1179/026708385790124134
17 PIETZSCH, R. et al. Simulation of the distortion of long steel profiles during cooling. Journal of Applied Mechanics, v. 74, n. 3, p. 427-37, May 2007. http://dx.doi.org/10.1115/1.2338050
18 TOTTEN, G. E.; HOWES, M.A. Steel heat treatment handbook. New York: Marcel Deker, 1997.
19 LI, H.; ZHAO, G.; HE, L. Finite element method based simulation of stress-strain field in the quenching process. Materials Science and Engineering A, v. 478, n. 1-2, p. 276-90, Apr. 2008. http://dx.doi.org/10.1016/j. msea.2007.05.101
20 ROHDE, J.; JEPPSSON, A. Literature review of heat treatment simulations with respect to phase transformation, residual stresses and distortion. Scandinavian Journal of Metallurgy, v. 29, n.2, p. 47-62, Apr. 2000. http://dx.doi. org/10.1034/j.1600-0692.2000.d01-6.x