Abstract
The microstructure of austenite at high temperatures, which cannot be reserved at room temperatures, determines the properties of its transformed phase in low-alloy steels. Consequently, an accurate method is herein developed to reconstruct local orientations of the parent austenite ( γ ) phase from electron backscatter diffraction maps of the martensite ( α ′ ) microstructure. The orientation map of α ′ is cropped into a grid of data squares as the reconstruction unit. The cropped square is then divided into the square inherited from only one γ grain and the square inherited from more than one γ grain. The local orientations around parent γ grain boundaries are more accurately determined using a newly proposed reconstruction criterion. Furthermore, the solution spaces for the orientation relationship and the parent γ orientation are refined, which simultaneously improves the calculation accuracy and efficiency of reconstruction procedure. The validated reconstruction method is applied to obtain local orientations of the deformed γ microstructure accurately.
Highlights
In low-alloy steels, the grain size, morphology, and crystallographic orientations of the austenite (γ) phase at high temperature are known to determine the microstructures and properties of the product phase
The proposed reconstruction criterion enhanced the manipulation of reconstruction around parent γ grain boundaries (PAGB) as well as some special boundaries
When analyzing the behavior of DRX using electron backscatter diffraction (EBSD), it is necessary to obtain the distribution of low angle boundaries and angle boundaries
Summary
In low-alloy steels, the grain size, morphology, and crystallographic orientations of the austenite (γ) phase at high temperature are known to determine the microstructures and properties of the product phase. Miyamoto et al proposed another method to reconstruct the parent γ orientation: minimizing the angular deviation between the experimental α0 orientations and the predicted ones [8,9] This method includes subdivision of the EBSD map using a grid of squares and calculating the local γ orientation for each square. When the cropped region around the grain boundaries of the parent phase contains α0 variants transformed from distinctly different γ grains, a mis-indexing γ orientation will be figured out. This method is time-consuming, because it intends to use all the scanned data for the calculation of γ orientation. Based on the validated reconstruction method, an automatic reconstruction program is developed and applied to the reconstruction of deformed γ microstructure from the orientation maps of inherited α0
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
