Tensile behaviour of a nanocrystalline bainitic steel containing 3 wt% silicon

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:549

Article

Garcia-Mateo, C.¹  Caballero, F. G.¹  Sourmail, T.²  Kuntz, M.³  Cornide, J.¹  Smanio, V.²  Elvira, R.⁴ 

[1] Natl Ctr Met Res CENIM CSIC, MATERALIA Res Grp, Dept Phys Met, Madrid 28040, Spain

[2] Ascomet CREAS Res Ctr Met, F-57301 Hagondange, France

[3] Robert Bosch GmbH, Mat & Proc Engn Met, D-70442 Stuttgart, Germany

[4] Gerdau Sidenor I D SA, Basauri 48970, Spain

关键词: Bainite;    Nanostructures ferrite;    Mechanical properties;    TRIP;   

DOI  :  10.1016/j.msea.2012.04.031

来源: Elsevier

【 摘 要 】

Much recent work has been devoted to characterize the :microstructure and mechanical properties bainitic nanostructured steels. The microstructure is developed by isothermal heat treatment at temperatures as low as 125-350 degrees C and adapted steel grades typically contain high carbon contents to achieve sufficient depletion of the B-s-M-s temperature range, and above 1.5 Si wt.% to suppress carbide formation during isothermal holding. On the latter, most of the published literature agrees on a limit of around 1.2-1.5 wt.% to suppress cementite in high carbon steels. For this reason perhaps, additions of Si significantly above this limit have not been investigated systematically in the context of nanostructured bainitic steels. The present work is concerned with the effect of up to similar to 3 Si wt.% in a steel grade adapted to low temperature bainitizing. Tensile properties as compared to similar grades, though with lower Si contents, exhibited unrivalled combinations of strength and ductility, with above 21% total elongation for a UTS above 2 GPa. An attempt is made to explain the mechanical properties of this microstructure in terms of some of its most relevant and unique morphological and microstructural features. (c) 2012 Elsevier B.V. All rights reserved.

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