AN EXPERIMENTAL METHOD TO SIMULATE THE HOT STAMPING PROCESS
UM MÉTODO EXPERIMENTAL PARA SIMULAR O PROCESSO DE ESTAMPAGEM A QUENTE
Olah Neto, André; Verran, Guilherme Ourique; Dutra, Rodinei Rocha
Abstract
In this study a new experimental method using low closing pressure and a flat aluminum die was developed in order to investigate the hot stamping process of a 22MnB5 steel grade. Initially, an experimental set up was developed and validated. Next, experiments were carried out to evaluate the behavior of this steel when subjected to quenching, using this experimental set up and different cooling conditions such as water, oil and air. Results were assessed by cooling curves, as well as by mechanical tests and metallographic analyzes. Cooling rates close to 110o C/s, hardness up to 480HV and ultimate tensile strength up to 1600 MPa were achieved, which are considered acceptable values for this steel in normal conditions of hot stamping
Keywords
Resumo
Nesta pesquisa foi desenvolvido um novo método experimental, utilizando baixa pressão de fechamento e uma matriz plana de alumínio, com o objetivo de investigar o processo de estampagem a quente do aço 22MnB5. Inicialmente um aparato experimental foi desenvolvido e validado. A seguir foram realizados experimentos com o objetivo de avaliar o comportamento deste aço quando submetido a diferentes meios de têmpera, usando este método e diferentes condições de resfriamento, tais como água, óleo e ar. Os resultados foram avaliados usando curvas de resfriamento, bem como ensaios mecânicos e análises metalográficas. Foram obtidas taxas de resfriamento próximas de 1000 C/s, durezas acima de 480HV e limite de resistência acima de 1600 MPa, valores que são considerados aceitáveis para este aço em condições normais de estampagem a quente.
Palavras-chave
Referências
1 Karbasian H, Tekkaia AE. A review on hot stamping. Journal of Materials Processing Technology. 2010;210:2103-2118.
2 Gorni AA. Novas tendências no processo de estampagem a quente. Corte &Conformação de Metais. 2010;62:62-77.
3 Naderi M. Hot stamping of ultra high strength steels [master’s thesis]. Aachen: Rheinish-Westfälischen Technischen Hochshule; 2007.
4 Nishibata T, Kojima N. Effect of quenching rate on hardness and microstructure of hot-stamped steel. Journal of Alloys and Compounds. 2013;577S:549-555.
5 Turetta A. Investigation of thermal, mechanical and microstructural properties of quenchable high strength steels in hot stamping operations [doctor thesis]. Padova: Univesita Degli Studi di Padova; 2008.
6 Bandyopadhyay PS, Kundu SK, Ghosh SK, Chatterjee S. Structure and properties of a low-carbon, microalloyed, ultra-high-strength steel. Metallurgical and Materials Transactions. 2011;42A:1051-1061.
7 Steinbeiss H, So H, Michelitsch T, Hoffmann H. Method for optimizing the cooling design of hot stamping tools Production Engineer. Research for Development. 2007;1(2):149-155.
8 Naganathan A. Hot Stamping of manganese boron steel [master’s thesis] Ohio: Ohio State University; 2010.
9 Cui J, Lei C, Xing Z, Li C, Ma S. Predictions of the mechanical properties and microstructure evolution of high strength steel in hot stamping. Journal of Materials Engineering and Performance. 2012;21(11):2244-2254.
10 Geiger M, Merklein M, Lechler J. Determination of tribological conditions within hot stamping. Product Engineer Research Development. 2008;2:269-276.
11 Merklein M, Lechler J, Stoehr T. Investigations on the thermal behavior of ultra-high strength boron manganese steels within hot stamping. International Journal of Material Forming. 2009;2(1):259-262.
12 Ravindran D. Finite element simulation of hot stamping [master’s thesis] Ohio: Ohio State University; 2011.
13 Hu P, Ying L, Li Y, Liao Z. Effect of oxide scale on temperature-depend interfacial heat transfer in hot stamping process. Journal of Materials Processing Technology. 2013;213(9):1475-1483.
14 Caron E, Daun KJ, Wells MA. Experimental characterization of heat transfer coefficients during hot forming die quenching of boron steel. Metallurgical and Materials Transactions. B, Process Metallurgy and Materials Processing Science. 2013;44B(2):332-343.
15 Bai Q, Lin J Zhan L, Dean T, Balint D, Zhang Z. A new method determining interfacial heat transfer coefficient and its application in hot/warm forming. In: Proceedings of the 14th International Conference Metal Forming; 2012; Krakón, Poland. Local de publicação: Editora Wenhein - Germany Editora: Wiley-VCH Verlag GmbH & Co. KGaA; 2012. p. 1035-1038.
16 Olah A No. Estudo do efeito da deformação plástica sobre a cinética de transformação de fase do aço 22MnB5 estampado a quente [tese de doutorado] Joinville: Universidade do Estado de Santa Catarina; 2015.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email