Abstract
The influence of severe plastic deformation by means of conventional cold-rolling on the microstructure of a pre-processed ferritic-martensitic dual-phase steel was studied with respect to grain refinement and its impact on the mechanical properties of the steel. The deformed material is finally annealed by applying appropriate heat treatments, including intercritical annealing and HDG cycles, adjusted to the starting microstructure and the deformation degree. Microstructure investigations via light and electron microscopy show that ultrafine grain formation is achievable, with a ferrite mean grain size of ∼ 1.5 μm. Martensite grains are even finer. Tensile tests confirm the superior performance of such fine-grained microstructures, compared with the starting material. The ultimate tensile strength and the total elongation exhibit high values, while the yield stress remains at a remarkably low level (below 400 MPa). The mechanical properties can be correlated with the microstructural features of the material (grain size of ferrite, volume fraction of martensite).
| Original language | English |
|---|---|
| Pages (from-to) | 735-746 |
| Number of pages | 12 |
| Journal | Materials Science and Technology |
| Volume | 1 |
| State | Published - 2004 |
| Event | Materials Science and Technology, MS and T 2004; Volume 1: AIST Process Metallurgy, Product Quality and Applications Proceedings - New Orleans, LA, United States Duration: 26 Sep 2004 → 29 Sep 2004 |
Keywords
- Cold-rolling
- Dual-phase steels
- Grain refinement
- Ultrafine grains