AVALIAÇÃO DO COMPORTAMENTO MECÂNICO DO AÇO INOXIDÁVEL AUSTENÍTICO 304L VIA NANOINDENTAÇÃO
MECHANICAL BEHAVIOR EVALUATION OF 304L AUSTENITIC STAINLESS STEEL VIA NANOINDENTATION
Carolline Serafim da Silva, Camila Oliveira de Souza, Andrey de Moraes Barcelos Casanova, Rodolfo da Silva Teixeira, Juciane Maria Alves, Andersan dos Santos Paula, Luiz Paulo Mendonça Brandão
Resumo
Avaliou-se o comportamento mecânico do aço inoxidável austenítico 304L submetido à transformação martensítica induzida por deformação plástica com percentuais distintos durante a laminação a frio à temperatura ambiente e após tratamento térmico de recozimento, para reversão da martensita em austenita, em duas condições: 800 °C e 750 °C por 1 min. As propriedades mecânicas foram mensuradas via nanoindentação instrumentada com cargas máximas de ensaio de 1 e 20 gf e a evolução microestrutural, quanto a presença de martensita α’, foi avaliada ao longo das etapas de processamento pela técnica de ferritoscopia. Observou-se incremento das propriedades mecânicas após processo de laminação a frio quando comparadas à condição como recebida e tendência de estabilização quando comparadas entre si. Amostras do aço 304L tratadas à 800 ºC por 1 min obtiveram incrementos mais significativos nas propriedades mecânicas devido a alterações microestruturais mais acentuadas.
Palavras-chave
Abstract
The mechanical behavior of 304L austenitic stainless steel 304L was evaluate after transformation induced plasticity during cold rolling at room temperature up distinct thickness reduction and after annealing heat treatment, for reversion of the martensite in austenite, in two conditions: 800 °C and 750 °C during 1 min. The mechanical properties were measured via instrumented nanoindentation with distinct maximum loads (1 and 20 gf) and the microstructural evolution was evaluated along the processing stages by ferritoscopy. It was observed an increase of the mechanical properties after the cold rolling process when compared to the condition as received and the tendency of stabilization when compared to each other. Samples of 304L steel treated at 800 °C for 1 min showed more significant increases in mechanical properties due to more pronounced microstructural changes.
Keywords
References
1 Lo KH, Shek CH, Lai JKL. Recent developments in stainless steels. Materials Science and Engineering. 2009;65:39-104.
2 Oshima T, Habara Y, Kuroda K. Efforts to save nickel in austenitic stainless steels. ISIJ International. 2007;12:359-362.
3 Behjati P, Kermanpur A, Najafizadeh A. Application of martensitic transformation fundamentals to select appropriate alloys for grain refining through martensite thermomechanical treatment. Metallurgical and Materials Transactions. 2013;44:3524-3530.
4 Shirdel M, Mirzadeh H, Parsa MH. Nano/ultrafine grained austenitic stainless steel through the formation and reversion of deformation-induced martensite: Mechanisms, microstructures, mechanical properties, and TRIP effect. Materials Characterization. 2015;103:150-161.
5 Shin HC, Ha TK, Chang W. Kinetics of deformation induced martensitic transformation in a 304 stainless steel. Scripta Materialia. 2001;45(7):823-829.
6 Ghosh SK, Mallick P, Chattopadhyay PP. Effect of reversion of strain induced martensite on microstructure and mechanical properties in an austenitic stainless steel. Journal of Materials Science. 2011;46:3480-3487.
7 Hamada AS, Kisko AP, Sahu P, Karjalainen LP. Enhancement of mechanical properties of a TRIP-aided austenitic stainless steel by controlled reversion annealing. Materials Science and Engineering A. 2015;628:154-159.
8 Misra RDK, Zhanga Z, Jia Z, Venkatsuryaa PKC, Somanib MC, Karjalainenb LP. Nanoscale deformation experiments on the strain rate sensitivity of phase reversion induced nanograined/ultrafine-grained austenitic stainless steels and comparison with the coarse-grained counterpart. Materials Science and Engineering A. 2012;548:161-174.
9 Rezaee A, Kermanpur A, Najafizade A, Moallemi M. Production of nano/ultrafine grained AISI 201L stainless steel through advances thermo-mechanical treatment. Materials Science and Engineering A. 2011;528:5025-5029.
10 Rezaee A, Kermanpur A, Najafizadeh A, Moallemi M, Samaei Baghbadorani H. Investigation of cold rolling variables on the formation of strain-induced martensite in 201L stainless steel. Materials & Design. 2013;46:49-53.
11 Talonen J, Aspegren P, Hänninen H. Comparison of different methods for measuring strain induced α′-martensite content in austenitic steels. Materials Science and Technology. 2004;20:1506-1511.