The microstructure, dimple structure, and mechanical properties of a cold-rolled Fe-18Mn-0.6C-1.5Al TWIP steel were investigated as a function of annealing temperature. The recrystallization started at 600 °C and finished at 700 °C for the holding time of 10 min. The coarsening rate of recrystallized grains was increased over about 840 °C and Rockwell hardness was greatly decreased between 800 and 900 °C, which shows a good agreement with the equilibrium dissolution temperature of M3C carbides. The reversion of the tensile strength occurred between 700 and 800 °C because of the carbide precipitation hardening. The precipitation-time-temperature diagram was generated by dilatometric tests, showing a nose temperature of 800 °C. The dimple size was decreased to 700 °C and then increased again with higher annealing temperature, having a strong proportional relationship with austenite grain size.
Bibliographical noteFunding Information:
This study was supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Commerce, Industry and Energy , Republic of Korea.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering