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TEM and MDS study of NPSS


EMSL Project ID
32712

Abstract

Nano-Precipitates Strengthening Steels (NPSS) are currently under consideration for use as various vehicle components in the automotive industry for their excellent combination of mechanical properties. Our study is inspired by the recent research progress, which indicate that, whereas the specific approaches to produce nano-precipitates are drastically different, they all have resulted in excellent combination of strength, ductility and press formability. This is a very critical observation for our study. First, it demonstrates the inherent advantages of nano-precipitate strengthening in steels that are not unique to, or rely on, a specific mechanism in forming nano-precipitate, provided that certain basic attributes of nano-precipitates (size, morphology, distribution, and precipitate/matrix interface characteristics) be met. Second, it indicates the possibility of forming â??desiredâ?? nano precipitates by other approaches. Last but not least, NPSS can be made in ferritic phase matrix, a very important fact related to the cost of NPSS. The ultimate goal of this study is to quantify the effects of size, shape and spacing/distribution of nano-precipitates on the deformation behavior of NPSS based on Transmission Electron Microscopy (TEM) study and subsequent mechanistic modeling and experiments in order to acquire a fundamental understanding of the nano-precipitate strengthening mechanisms.

Project Details

Project type
Exploratory Research
Start Date
2009-02-05
End Date
2010-02-07
Status
Closed

Team

Principal Investigator

Xin Sun
Institution
Pacific Northwest National Laboratory

Team Members

Yongfeng Shen
Institution
Pacific Northwest National Laboratory

Kyoo Sil Choi
Institution
Pacific Northwest National Laboratory

Related Publications

Characterization of Thermo-Mechanical Behaviors of Advanced High Strength Steels (AHSS). Final Report FY09.
Characterization of Thermo-Mechanical Behaviors of Advanced High- Strength Steels (AHSS): Formability, Weldability and Performance Evaluations of AHSS Parts for Automotive Structures (Project 18987/ Agreement 14687). Progress Report FY09.
Soulami A, KS Choi, YF Shen, WN Liu, X Sun, and MA Khaleel. 2011. "On deformation twinning in a 17.5%Mn-TWIP steel: A physically-based phenomenological model." Materials Science and Engineering. A. Structural Materials: Properties, Microstructure and Processing 528(3):1402-1408. doi:10.1016/j.msea.2010.10.031