Strain hardening and micro-deformation behavior in advanced DP and TRIP steels: EBSD examinations and crystal plasticity simulations

N. Saeidi, M. Jafari, F. Ashrafizadeh, M. Karimi, S. Ziaei-Rad and H.S. Kim

Materials Research Express, Volume 5, Number 12, September 2018, 126507

ABSTRACT

Deformation behavior of fine-grained commercial TRIP780 and DP780 steels was studied using tensile tests and field emission scanning electron microscopy (FESEM)/electron backscatter diffraction (EBSD) analyses, as well as numerical investigation. The analyses of EBSD data via an image quality map of deformed specimens showed that the greater deformation of TRIP steel than that of DP steel was found to be mostly due to the formation of a high number of interrupted and discrete shear bands, leading to cell structure within the microstructure of the TRIP steel. The uniform strain distribution measured within the gage length of the specimens also verified that more of the strain hardening capacity in the TRIP steel was exploited than in the DP steel. Moreover, employing crystal plasticity-based numerical simulations, austenite transformation and localized plastic deformation and their effects on the strain hardening behavior of the TRIP780 steel was studied and compared with that of the DP780 steel.

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