Effect of the anisotropy of martensitic transformation on ferrite deformation in Dual-Phase steels. (July 2022)

• Record Type: Journal Article
• Authors: Atreya, Vibhor; Van Dokkum, Jan Steven; Bos, Cornelis; Santofimia, Maria J.
• Is Part Of: Materials & design. Volume 219(2022)
• Publication Date: 2022-07
• Subjects: Dual-phase steel -- Martensitic transformation -- Electron backscatter diffraction -- Plastic deformation -- Martensite variants -- Micromechanical modeling; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2022.110805
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: The proposed modeling approach estimates martensitic transformation-induced deformation of ferrite in DP steels. The anisotropy of transformations is found to be a significant factor determining the deformation of ferrite. An influence of PAG orientation and the variant formation on transformation-induced deformation of ferrite is shown. This study illustrates an essential step towards a general macroscopic model of plasticity in DP steels. Abstract: The volume increase and shape change during austenite to martensite transformation in dual-phase (DP) steels are largely accommodated in the microstructure by the deformation of the surrounding ferrite matrix. Accurate estimation of transformation-induced deformation of ferrite via experiments and modeling is essential for predicting the subsequent mechanical behavior of DP steels. This study aims to illustrate the disadvantages of simplifying the anisotropic transformation deformation of martensite to isotropic dilatation for modeling the transformation-induced deformation of ferrite. A novel methodology is developed comprising sequential experimental and numerical research on DP steels to quantify transformation-induced strains in ferrite. This methodology combines the results of prior austenite grain reconstruction, phenomenological theory of martensite crystallography and electron backscatter diffraction (EBSD) orientation data to estimate variant-specific transformation deformation. Subsequently, by comparison of full-field micromechanical calculation results on a virtual DP steel microstructure with experimental EBSD kernel average misorientation and geometrically necessary dislocation measurement results it is shown that neglecting the shear deformation associated with the martensitic transformation leads to significant underestimation in the prediction of transformation-induced strains in ferrite.