Title of article :
Hot Deformation Behavior of 17-7 PH Stainless Steel
Author/Authors :
Farmanesh Kh. نويسنده Department of Material Engineering, Malek Ashtar University, Shahin Shahr, Iran. , Zeinali M. نويسنده Maleke Ashtar University of Technology , Shafiei E. نويسنده Department of Mining and Metallurgical Engineering - Amirkabir University of Technology , Hosseini R. نويسنده Department of Materials Science and Engineering - Shiraz University , Soltanipoor A. R. نويسنده Maleke Ashtar University of Technology , Maghsodi E. نويسنده Department of Materials Science and Engineering - Maleke Ashtar University of Technology - Shahin Shahr
Abstract :
To investigate the hot deformation behavior of 17-7 PH stainless steel, hot compression tests were carried out at the temperatures of 950, 1050 and 1150 oC and strain rates of 0.001 s-1 to 0.1 s-1. Accordingly, the hot working behavior was studied by the analyses of flow stress curves, work hardening rate versus stress curves, exponent- type constitutive equations and deformed microstructures. Meanwhile, the average normalized critical stress for initiation of dynamic recrystallization (DRX) was determined using a 3rd order polynomial curve fitting. The results show that the flow stress depends strongly on the deformation temperature and the strain rate, and it increases with decreasing the deformation temperature and increasing the strain rate. Furthermore, it was found out that the co- existence of ?- ferrite lowers the softening rate at high Z (Zener- Holloman parameter) conditions. The experimental results were then used to determine the constants of constitutive equations. There is a good agreement between the measured and predicted results indicating a high accuracy of exponent- type constitutive equations.
Journal title :
Astroparticle Physics
