Mechanical behaviour and micromechanical modelling of medium-Mn steel microstructure evolution. (15th April 2022)

• Record Type: Journal Article
• Authors: Kozłowska, Aleksandra; Grajcar, Adam; Opara, Jarosław; Kaczmarczyk, Jarosław; Janik, Aleksandra; Radwański, Krzysztof
• Is Part Of: International journal of mechanical sciences. Volume 220(2022)
• Publication Date: 2022-04-15
• Subjects: Advanced high strength steel -- Micromechanical modelling -- Steel sheet -- TRIP effect -- Retained austenite -- Medium-Mn steel -- Lightweighting; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2022.107151
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: Finite element modelling and experimental approaches enabled to monitor the microstructure evolution of novel medium-Mn steel. Micromechanical modelling revealed its suitability to assess stress gradients in TRIP steels. The chemical and mechanical driving forces for strain-induced martensitic transformation were determined. The temperature-dependant mechanical behaviour of TRIP steel was provided. Abstract: Intense research efforts are focused on the development of advanced medium-manganese steels intended for lighweight automotive components and other applications, where high strength and good formability are crucial. The mechanical and technological properties of such steels depend on the strain-induced martensitic transformation (SIMT) of metastable retained austenite (RA), which is affected by several factors including a deformation temperature. The response of the retained austenite to strain-induced martensitic transformation at various temperatures (-60 °C-200 °C) was studied in the advanced medium-Mn 0.17C-3.3Mn-1.7Al-0.22Si steel via tensile testing. It was found that the efficiency of martensitic transformation decreases with increasing the deformation temperature in a range from -60 °C to 100 °C. At 140 °C and 200 °C, the strain hardening ability and strain-induced martensitic transformation were additionally affected by thermally activated processes. The obtained experimental data was applied into a thermodynamic model in order to predict the temperature-dependant stability of retained austenite. Furthermore, the micromechanical modelling using the finite element method was utilized to perform an analysis at the microscale level of the SIMT of the RA during plastic deformation. The experimental and modelling approaches were found to be complementary methods to comprehensively evaluate the mechanical response of investigated steel as well as microstructure evolution of structural constituents at progressive strain levels. Graphical abstract: Image, graphical abstract