Abstract
A new inverse method was developed to predict the stress-strain behaviors of constituent phases in a multi-phase steel using the load-depth curves measured in nanoindentation tests combined with microhardness measurements. A power law hardening response was assumed for each phase, and an empirical relationship between hardness and yield strength was assumed. Adjustment was made to eliminate the indentation size effect and indenter bluntness effect. With the newly developed inverse method and statistical analysis of the hardness histogram for each phase, the average stress-strain curves of individual phases in a quench and partitioning (Q&P) steel, including austenite, tempered martensite and untempered martensite, were calculated and the results were compared with the phase properties obtained by in-situ high energy X-ray diffraction (HEXRD) test. It is demonstrated that multi-scale instrumented indentation tests together with the new inverse method are capable of determining the individual phase flow properties in multi-phase alloys.
Original language | English |
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Pages (from-to) | 384-395 |
Number of pages | 12 |
Journal | Materials Science and Engineering: A |
Volume | 652 |
DOIs | |
State | Published - Jan 15 2016 |
Externally published | Yes |
Funding
Pacific Northwest National Laboratory (PNNL) is operated by Battelle Memorial Institute for the US Department of Energy (DOE) under Contract no. DE-AC05-76RL01830. This work was funded by the DOE's Vehicle Technologies Office under the Automotive Lightweight Materials Program managed by Dr. William Joost. The helps of Mr. Mark Taylor in the Advanced Steel Processing and Products Research Center at the Colorado School of Mines for the nanoindentation tests are greatly appreciated.
Funders | Funder number |
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U.S. Department of Energy | DE-AC05-76RL01830 |
Battelle | |
Vehicle Technologies Office |
Keywords
- Microstructure
- Multi-phase
- Nanoindentation
- Plastic flow properties