Abstract
The stability of individual metastable austenite grains in low-alloyed TRIP steels has been studied during tensile loading using high-energy X-ray diffraction. The carbon concentration, grain volume and grain orientation with respect to the loading direction was monitored for a large number of individual grains in the bulk microstructure. Most austenite grains transform into martensite in a single transformation step once a critical load is reached. The orientation-dependent stability of austenite grains was found to depend on their Schmid factor with respect to the loading direction. Under the applied tensile stress the average Schmid factor decreased from an initial value of 0.44 to 0.41 at 243MPa. The present study reveals the complex interplay of microstructural parameters on the mechanical stability of individual austenite grains, where the largest grains with the lowest carbon content tend to transform first. Under the applied tensile stress the average carbon concentration of the austenite grains increased from an initial value of 0.90 to 1.00 wt% C at 243MPa, while the average grain volume of the austenite grains decreased from an initial value of 19 to 15 μm3 at 243MPa.
Original language | English |
---|---|
Pages (from-to) | 280-287 |
Number of pages | 8 |
Journal | Materials Science and Engineering: A |
Volume | 618 |
DOIs | |
Publication status | Published - 7 Nov 2014 |
Bibliographical note
Funding Information:We acknowledge the European Synchrotron Radiation Facility for provision of synchrotron radiation facilities and thank the beam line staff for assistance in using beam line ID11. This research was carried out under the project number M41.5.08313 in the framework of the Research Program of the Materials innovation institute M2i ( www.m2i.nl ).
Publisher Copyright:
© 2014 Elsevier B.V.
Keywords
- Martensite
- Steel
- Synchrotron X-ray diffraction
- Tensile deformation
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering