Hardening Behavior Characterization of Dual Phase Steels
The requirements for higher passenger safety, improved fuel economy and weight reduction in automobile industry necessitates the usage of advanced high strength steel (AHSS) grades. Dual phase (DP) steels are the most widely used one among AHSS. DP steels become increasingly popular, since they provide a combination of sufficient formability at room temperature and tensile strength over 1000 MPa. The current standards for DP steels only specifies yield and tensile strength. Steels from various producers have considerably different composition and microstructure; however they still have the same grade name. Combined with the inherited heterogeneous microstructure, those steels exhibit different hardening behavior. The aim of this study is to evaluate the hardening behavior of DP800 steels, obtained from different vendors and thus having different compositions and microstructures. The hardening behavior was characterized with tensile tests performed along rolling and transverse directions. The microstructure has been characterized with optical and scanning electron microscopes. The martensite fraction, grain size of ferrite and type and fraction of alloying elements has been correlated to the hardening behavior.
Dual phase steels, hardening behavior, alloying design
2. Billur E, et al. New Generation Advanced High Strength Steels: Developments, Trends and Constraints. International Journal of Scientific and Technological Research 2, pp.50-62, 2016.
3. Speich GR. Dual Phase Steels, ASM International, ABD, 1990.
4. Singh RR, et al. Comparison of Mechanical Properties of Medium Carbon Steel with Dual Phase Steel. International Journal of Mechanical Engineering 4, pp. 1-8, 2008.
5. Tsipouridis P. Mechanical Properties of Dual Phase Steels. Ph.D. Thesis, Technische Universitat München, Germany, 2006.
7. Darabi A Ch, et al. Micromechanical Analysis of Two Heat-Treated Dual Phase Steels: DP 800 and DP 980, Mechanics of Materials 110, pp. 68-83, 2017.
8. Huang TT, et al. Strain-hardening Behaviors of Dual Phase Steels with Microstructure Features, Material Science and Engineering A. 672, pp. 88-97 2016.
9. Parasad GVSS. An Improved Dislocation Density Based Work Hardening Model for Al-Alloys. Master Thesis, RWTH Germany, 2007.
10. LePera F. Improved Etching Technique for the Determination of Percent Martensite in High-Strength Dual-phase Steels, Metallography 12, pp. 263-268, 1979.
11. Taşan CC, et al. Integrated Experimental-simulation Analysis of Stress and Strain Partitioning in Multiphase Alloys. Acta Materiala 81, pp. 386-400, 2014.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
All the intellectual property rights of the papers accepted for the publication belong to the Hittite Journal of Science & Engineering.