Study on flow properties of rotor grade steel

Compression tests were performed on Gleeble 3800 Thermo-Mechanical Simulator to study the flow properties of rotor grade steel 28CrMoNiV59. Compression specimens were deformed at a constant strain rate of 10-3 s-1. The temperature range during tests was between room temperature and 1000°C with an interval of 100°C. When the normalized flow stress was plotted as a function of temperature, it exhibited three different regions. In regions I and III flow stress decreases with increase in temperature but the same increases with temperature in region II. Microstructural changes and work hardening behaviour have been studied for the deformed specimen. Furthermore, TEM analysis was also done for the samples of these three different regions (I, II & III). Strain hardening rate as a function of the normalized flow stresses decreases at larger strain and become negligible at higher temperature.