Estudo da conformabilidade do aço inoxidável AISI 409 sob rotas complexas de deformação
Study of AISI 409 stainless steel formability under complex deformation routes
Frederick Louis Dias de Morais, Elaine Carballo Siqueira Corrêa, Wellington Lopes
Resumo
Nas diversas operações de conformação é necessária a combinação de diferentes esforços mecânicos até que sejam alcançadas a forma e as dimensões de um produto. A severidade dessas mudanças no modo de deformação pode ocasionar modificações inesperadas no comportamento mecânico de um material, restringindo o uso do mesmo em processos industriais. Considerando essa abordagem, este trabalho apresenta o estudo da conformabilidade do aço inoxidável ferrítico AISI 409 sob duas rotas de processamento mecânico, com o objetivo de analisar a evolução da resistência mecânica e da ductilidade desse aço. Neste caso, chapas do aço AISI 409 foram submetidas a uma combinação de tensões compressivacisalhante (laminação), tração e cisalhamento (de modo direto e reverso) de forma a promover mudanças severas no modo de deformação plástica. Os resultados revelaram a influência da quantidade de pré-deformação efetiva (variando de 3,88% a 16,50%), do estado inicial do material (recozido e laminado a frio), do modo de deformação plástica (laminação, tração e cisalhamento) no endurecimento e na ductilidade do aço AISI 409, exibindo ainda transientes na taxa de encruamento associados com o modo de pré-deformação em laminação a frio.
Palavras-chave
Abstract
In sheet metal forming operations is necessary a combination of several types of mechanical efforts until the final shape and dimensions of a product. The severity of these changes in the deformation mode can cause unexpected responses in the mechanical behaviour of a material, constrain its use in industrial processes. Considering this approach, this work presents a study of the formability of ferritic stainless steel (AISI 409) under two different routes of mechanical processing, with the aim of analysing the evolution of the mechanical strength and ductility of this steel. In this case, AISI 409 steel sheets were subjected to a combination of compressive shear stresses (rolling), tensile and shear (direct and reverse modes) to provide severe changes in the plastic deformation mode. The results revealed the influence of the amount of effective prestrain values (ranging from 3.88% up to 16.50%), the initial condition of the material (annealed and cold rolled), the mode of plastic deformation (rolling, tensile and shear) on hardening and ductility of AISI 409 steel, still displaying transients of the hardening rate associated with the cold rolling prestrain mode.
Keywords
Referências
1 Laukonis JV, Ghosh AK. Effects of strain path changes on the formability of sheet metals. Metallurgical Transactions. 1978;9(12):1849-1856.
2 Othmen KB, Sai K, Manach PY, Elleuch K. Reverse deep drawing process: material anisotropy and work-hardening effects. Journal of Materials: Design and Applications. 2019;233(4):699-713.
3 Dieter GE. Mechanical metallurgy. 3rd ed. New York: McGraw-Hill Companies; 1986.
4 Lucchetta A, Auslender F, Bornert M, Kondo D. A double incremental variational procedure for elastoplastic composites with combined isotropic and linear kinematic hardening. International Journal of Solids and Structures. 2019;158:243-267.
5 Badreddine H, Saanouni K, Labergère C, Duval J-L. Effect of the kinematic hardening on the plastic anisotropy parameters for metallic steels. Comptes Rendus. Mécanique. 2018;346(8):678-700.
6 Meyers MA, Chawla KK. Princípios de metalurgia mecânica. São Paulo: Edgard Blücher; 1982.
7 Rauch EF, Gracio JJ, Barlat F, Lopes AB, Duarte JF. Hardening behaviour and structural evolution upon strain reversal of aluminum alloys. Scripta Materialia. 2002;46(12):881-886.
8 Qin J, Holmedal B, Hopperstad OS. Experimental characterization and modelling of aluminum alloy AA3103 for complex single and double strain-path changes. International Journal of Plasticity. 2019;112:158-171.
9 Wang H, Lu C, Tieu K. Crystal plasticity modelling of microbands in a rolled aluminium single crystal. Materialia. 2019;8:100488.
10 Associação Brasileira de Normas Técnicas. ABNT NBR 6892: materiais metálicos: ensaio de tração à temperatura ambiente. ABNT; 2018.
11 Rauch EF. The flow law of mild steel under monotonic or complex strain path. Diffusion and Defect Data, Solid State Data. Part B, Solid State Phenomena. 1992;23-24:317-333.
12 Chung K, Wagoner RH. Effect of stress-strain-law transients on formability. Metallurgical Transactions. 1986;17(6):1001-1009.
13 Lopes AB, Rauch EF, Gracio JJ. Textural vs structural plastic instabilities in sheet metal forming. Acta Materialia. 1999;47(3):859-866.
14 Zandrahimi M, Platias S, Frice D, Barrett D, Bate PS, Roberts WT. Effects of changes in strain path on work hardening in cubic metals. Metallurgical Transactions. 1989;20(11):2471-2482.
15 Han K, Van Tyne CJ, Levy BS. Effect of strain and strain rate on the Bauschinger effect response of three different steels. Metallurgical and Materials Transactions. 2005;36(9):2379-2384.
16 Mahato JK, De PS, Sarkar A, Kundu A, Chakraborti PC. Effect of prestrain and stress rate on Bauschinger effect of monotonically and cyclically deformed OFHC copper. Procedia Engineering. 2014;74:368-375.
17 Pham CH, Adzima F, Coer J, Manach PY. Anti-buckling device for ultra-thin metallic sheets under large and reversed shear strain paths. Experimental Mechanics. 2017;57(4):593-602.
Submetido em:
07/04/2020
Aceito em:
30/10/2020
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