| الوصف: |
In the present paper, the effects of deformation temperature on phase transformations behavior of the steel BR1500HS during isothermal and non-isothermal deformations are described and discussed. Thermal mechanical simulation tests were carried out on GLEEBLE 1500 thermal simulator, Some specimens are uniaxially extended with strain rate 10/s and their largest deforming degree reaches 15% at 950°C. After deformation, the specimens are cooled to room temperature at different cooling rates, 0.5, 1, 5, 10, 20, 30°C/s, respectively. And the others are nonisothermal uniaxially extended with strain rate 10/s with strain value 15% from the initial deformation temperature of 800°C, and simultaneously cooled to different temperature, 400, 450, 500, 550, 600, 650 and 700°C, respectively. The isothermal deforming microstructures of steel BR1500HS are mainly composed of ferrite and pearlite at a cooling rate range of 0.5 to 1°C/s. When the cooling rate gets to 5°C/s, the microstructures are mainly bainite and some martensite. And the cooling rate is higher than 30°C/s, fully martensitic transformation are accomplished in the experimental steel. The non-isothermal deforming microstructures, however, no martensite phase can be seen. Even the amount of bainite phase is minimal, too.Copyright © 2012 by ASME |
