�й������ڿ���  2016, Vol. 23 Issue (3): 244-252 DOI: |
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| Effects of Temperature and Strain Rate on Flow Behavior and Microstructural Evolution of Super Duplex Stainless Steel under Hot Deformation | ||||
| Ming MA1,Hua DING1,Zheng-you TANG1,Jing-wei ZHAO2,Zhou-hua JIANG1,Guang-wei FAN3 | ||||
| 1. School of Material Science and Engineering, Northeastern University, Shenyang 110819, Liaoning, China 2. School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522, Australia 3. Technology Center, Shanxi Taigang Stainless Steel Co., Ltd., Taiyuan 030003, Shanxi, China Hot compression tests were carried out in the temperature range of 1223-1473 K and strain rate range of 0.01-30 s-1 to investigate the flow behavior and microstructural evolution of super duplex stainless steel 2507 SDSS2507. It is found that most of the flow curves exhibit a characteristic of dynamic recrystallization DRX and the flow stress increases with the decrease of temperature and the increase of strain rate. The apparent activation energy Q of SDSS2507 with varying true strain and strain rate is determined. As the strain increases, the value of Q declines in different ways with varying strain rate. The microstructural evolution characteristics and the strain partition between the two constituent phases are significantly affected by the Zener-Hollomon parameter Z. At a lower lnZ, dynamic recovery DRV and continuous dynamic recrystallization CDRX of the ferrite dominate the softening mechanism during the compression. At this time, steady state deformation takes place at the last stage of deformation. In contrast, a higher lnZ will facilitate the plastic deformation of the austenite and then activate the discontinuous dynamic recrystallization DDRX of the austenite, which leads to a continuous decline of the flow stress even at the last deformation stage together with CDRX of the ferrite. |
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| Effects of Temperature and Strain Rate on Flow Behavior and Microstructural Evolution of Super Duplex Stainless Steel under Hot Deformation | ||||
| Ming MA1,Hua DING1,Zheng-you TANG1,Jing-wei ZHAO2,Zhou-hua JIANG1,Guang-wei FAN3 | ||||
| 1. School of Material Science and Engineering, Northeastern University, Shenyang 110819, Liaoning, China 2. School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522, Australia 3. Technology Center, Shanxi Taigang Stainless Steel Co., Ltd., Taiyuan 030003, Shanxi, China Hot compression tests were carried out in the temperature range of 1223-1473 K and strain rate range of 0.01-30 s-1 to investigate the flow behavior and microstructural evolution of super duplex stainless steel 2507 SDSS2507. It is found that most of the flow curves exhibit a characteristic of dynamic recrystallization DRX and the flow stress increases with the decrease of temperature and the increase of strain rate. The apparent activation energy Q of SDSS2507 with varying true strain and strain rate is determined. As the strain increases, the value of Q declines in different ways with varying strain rate. The microstructural evolution characteristics and the strain partition between the two constituent phases are significantly affected by the Zener-Hollomon parameter Z. At a lower lnZ, dynamic recovery DRV and continuous dynamic recrystallization CDRX of the ferrite dominate the softening mechanism during the compression. At this time, steady state deformation takes place at the last stage of deformation. In contrast, a higher lnZ will facilitate the plastic deformation of the austenite and then activate the discontinuous dynamic recrystallization DDRX of the austenite, which leads to a continuous decline of the flow stress even at the last deformation stage together with CDRX of the ferrite. |
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