Microstructure evaluation of an advanced high strength steel with superior results in terms of strength-ductility trade-off
Tairine Berbert Tavares, Fernando de Souza Costa, Marília Faria de Oliveira Caizer
Resumo
Major improvements in new advanced high strength steels, especially related to microstructural features, have been made by the steel sector to access the trade-off between strength and ductility. In this context, the present study provides a detailed analysis of the microstructure of a cold rolled steel with a minimum tensile strength of 980 MPa, which possesses superior elongation when compared to other conceptions of steels from the same strength level. The annealing process was simulated in a Gleeble machine, and the microstructural characterization was done using optical and scanning electron microscopy, EBSD and XRD analysis. Austenite decomposition, using dilatometric test, and mechanical properties were also evaluated. The steel characterization revealed a microstructure consisting of ferrite matrix with martensite islands and retained austenite particles, in a fraction equivalent to that of conventional TRIP steels, dispersed throughout. The carbon content in the austenite, however, was less than 1.0% w/w, which results in a relatively low stability. Therefore, the increase in strain hardening capacity enabled by the deformation-induced transformation of austenite to martensite produces increased ductility during straining, distinguishing the analyzed material from other steels of the same strength level.
Palavras-chave
References
1 Horvath CD. Advanced steels for lightweight automotive structures. In: Mallick PK, editor. Materials, design and manufacturing for lightweight vehicles. 2nd ed. Cambridge: Woodhead Publishing; 2021. p. 39-95.
2 Singh MK. Application of steel in automotive industry. International Journal of Emerging Technology and Advanced Engineering. 2016;6(7):246-253.
3 Galán J, Samek L, Verleysen P, Verbeken K, Houbaert Y. Advanced high strength steels for automotive industry. Revista de Metalurgia. 2012;48(2):118-131.
4 Nanda T, Singh V, Singh G, Singh M, Kumar BR. Processing routes, resulting microstructures, and strain rate dependent deformation behaviour of advanced high strength steels for automotive applications. Archives of Civil and Mechanical Engineering. 2021;7:1-24.
5 Kang J-Y, Park S, Moon M. Phase analysis on dual-phase steel using band slope of electron backscatter diffraction pattern. Microscopy and Microanalysis. 2013;19:13-16.
6 Chandrawanshi M, Singh RK, Sudharshan R. Development of high strength steel sheet with improved strain hardenability for automotive application. Chernaya Metallurgiya = Izvestiya Ferrous Metallurgy. 2019;62(9):827-832.
7 Soleimani M, Kalhor A, Mirzadeh H. Transformation-induced plasticity (TRIP) in advanced steels: a review. Materials Science and Engineering A. 2020;795(140023):1-14.
8 ASTM International. ASTM A370: standard test methods and definitions for mechanical testing of steel products. West Conshohocken: ASTM; 2011.
9 ASTM International. ASTM E562: standard test method for determining volume fraction by systematic manual point count. West Conshohocken: ASTM; 2019.
10 Bhadeshia HKDH, Edmonds DV. Analysis of mechanical properties and microstructure of high-silicon dual-phase steel. Metal Science. 1980;14(2):41-49.
11 Kang J, Kim DH, Baik S, Ahn T, Kim Y, Han HN, et al. Phase analysis of steels by grain-averaged EBSD functions. ISIJ International. 2011;51(1):130-136.
12 Wilson AW, Madison JD, Spanos G. Determining phase volume fraction in steels by electron backscattered diffraction. Scripta Materialia. 2001;45:1335-1340.
13 Ryde L. Application of EBSD to analysis of microstructures in commercial steels. Materials Science and Technology. 2006;22(11):1297-1306.
14 Wu J, Wray PJ, Garcia CI, Hua M, Deardo AJ. Image quality analysis: a new method of characterizing microstructures. ISIJ International. 2005;45(2):254-262.
15 Caballero FG, Capdevila C, García de Andres C. Modelling of kinetics and dilatometric behaviour of austenite formation in a low-carbon steel with a ferrite plus pearlite initial microstructure. Journal of Materials Science. 2002;37:3533-3540.
16 Ramos LF, Matlock DK, Krauss G. On the deformation behavior of dual-phase steels. Metallurgical Transactions A, Physical Metallurgy and Materials Science. 1979;10A:259-261.
17 Kim C. Modeling tensile deformation of dual-phase steel. Metallurgical Transactions A, Physical Metallurgy and Materials Science. 1988;19A:1263-1268.
18 Byun TS, Kim IS. Tensile properties and inhomogeneous deformation of ferrite-martensite dual-phase steels. Journal of Materials Science. 1993;28:2923-2932.
19 Sachdev AK. Effect of retained austenite on the yielding and deformation behavior of a dual phase steel. Acta Metallurgica. 1983;31(12):2037-2042.
Submitted date:
07/21/2021
Accepted date:
11/23/2021
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email