EBSD Analysis of Phase Compositions of TRIP Steel on Various Strain Levels

EBSD Analysis of Phase Compositions of TRIP Steel on Various Strain Levels

Článek recenzovaný mimo WoS a Scopus

Flat test bar made of TRIP steel was sequentially strained in tension. Eeach deformation step was made on a predefined strain level in which the phase composition was measured using EBSD; the analyses were made ex-situ exactly in the same area of 30x30 micrometer. Retained austenite (RA) was present in the form of elongated grains (plates) and roughly equiaxial ones. The RA content was initially 14.5% and decreased with imposed strain down to approximately 5% in selected strain range from 0% to 10%. This is in agreement to some extent with outcomes of both in-situ and ex-situ experiments presented by other authors, the difference beeing supposed either in data clean up or in variation in micriostructure of particular steel. Kernel average misorientation method was confirmed as useful tool to discern bainite and grainy ferrite in lightly deformed specimen. Problem arose in distinguishing between martensite and deformed ferrite at higher deformation levels because of high dislocation density and/or lattice distortion in both components. The ferrite and retained austenite fraction were analysed with sufficient accuracy; martensite fraction was established with high degree of uncertainty.

Flat test bar made of TRIP steel was sequentially strained in tension. Eeach deformation step was made on a predefined strain level in which the phase composition was measured using EBSD; the analyses were made ex-situ exactly in the same area of 30x30 micrometer. Retained austenite (RA) was present in the form of elongated grains (plates) and roughly equiaxial ones. The RA content was initially 14.5% and decreased with imposed strain down to approximately 5% in selected strain range from 0% to 10%. This is in agreement to some extent with outcomes of both in-situ and ex-situ experiments presented by other authors, the difference beeing supposed either in data clean up or in variation in micriostructure of particular steel. Kernel average misorientation method was confirmed as useful tool to discern bainite and grainy ferrite in lightly deformed specimen. Problem arose in distinguishing between martensite and deformed ferrite at higher deformation levels because of high dislocation density and/or lattice distortion in both components. The ferrite and retained austenite fraction were analysed with sufficient accuracy; martensite fraction was established with high degree of uncertainty.

Electron backscattering diffraction (EBSD), TRIP effect, Retained austenite

Electron backscattering diffraction (EBSD), TRIP effect, Retained austenite

MAN, O.; PANTĚLEJEV, L.; PEŠINA, Z.

2010

02.06.2009

University of Žilina

Žilina

1335-0803

Materiálové inžinierstvo

XVI

2

Slovenská republika

11

17

7