The hot deformation behavior of ultra purified 17% Cr ferritic stainless steel stabilized with Nb and Ti was investigated using axisymmetric hot compression tests on a thermomechanical simulator.The deformation was ca...The hot deformation behavior of ultra purified 17% Cr ferritic stainless steel stabilized with Nb and Ti was investigated using axisymmetric hot compression tests on a thermomechanical simulator.The deformation was carried out at the temperatures ranging from 700 to 1 100℃ and strain rates from 1to 10s-1.The microstructure was investigated using electron backscattering diffraction.The effects of temperature and strain rate on deformation behavior were represented by Zener-Hollomon parameter in an exponent type equation.The effect of strain was incorporated in the constitutive equation by establishing polynomial relationship between the material constants and strain.A sixth order polynomial was suitable to represent the effect of strain.The modified constitutive equation considering the effect of strain was developed and could predict the flow stress throughout the deformation conditions except at800℃in 1s-1 and at 700℃in 5and 10s-1.Losing the reliability of the modified constitutive equation was possibly ascribed to the increase in average Taylor factor at 800℃in 1s-1 and the increase in temperature at 700℃in 5and10s-1 during hot deformation.The optimum window for improving product quality of the ferritic stainless steels was identified as hot rolling at a low finisher entry temperature of 700℃,which can be achieved in practical production.展开更多
The influence of the finish rolling temperature on the microstructure and texture evolution of Nb and B micro-alloyed ultra purified Cr17 ferritic stainless steels was investigated. The hot rolled bands were produced ...The influence of the finish rolling temperature on the microstructure and texture evolution of Nb and B micro-alloyed ultra purified Cr17 ferritic stainless steels was investigated. The hot rolled bands were produced by conventional rolling process and the finish rolling at relatively low temperatures or "warm rolling". The microstructure was observed by optical microscopy, scanning electron microscopy and transmission electron microscopy, and X-ray diffraction was used to characterize the texture evolution processes. The results showed that as compared to conventional hot rolling process, the warm rolling has led to the refined and homogeneous microstructure and uniform recrystallization texture along γ-fiber in final sheets, indicating that the finish rolling at relatively low temperatures can be the effective way to improve significantly the formability of final sheets.展开更多
基金Sponsored by National Science and Technology Pillar Program during the Twelfth Five-year Plan Period of China(2012BAE04B02)National Natural Science Foundation of China(51271050)
文摘The hot deformation behavior of ultra purified 17% Cr ferritic stainless steel stabilized with Nb and Ti was investigated using axisymmetric hot compression tests on a thermomechanical simulator.The deformation was carried out at the temperatures ranging from 700 to 1 100℃ and strain rates from 1to 10s-1.The microstructure was investigated using electron backscattering diffraction.The effects of temperature and strain rate on deformation behavior were represented by Zener-Hollomon parameter in an exponent type equation.The effect of strain was incorporated in the constitutive equation by establishing polynomial relationship between the material constants and strain.A sixth order polynomial was suitable to represent the effect of strain.The modified constitutive equation considering the effect of strain was developed and could predict the flow stress throughout the deformation conditions except at800℃in 1s-1 and at 700℃in 5and 10s-1.Losing the reliability of the modified constitutive equation was possibly ascribed to the increase in average Taylor factor at 800℃in 1s-1 and the increase in temperature at 700℃in 5and10s-1 during hot deformation.The optimum window for improving product quality of the ferritic stainless steels was identified as hot rolling at a low finisher entry temperature of 700℃,which can be achieved in practical production.
基金supported by the National Natural Science Foundation of China (No.50734002)Baosteel and the Young Scientist Project of National Natural Science Foundation of China (No.51004035)
文摘The influence of the finish rolling temperature on the microstructure and texture evolution of Nb and B micro-alloyed ultra purified Cr17 ferritic stainless steels was investigated. The hot rolled bands were produced by conventional rolling process and the finish rolling at relatively low temperatures or "warm rolling". The microstructure was observed by optical microscopy, scanning electron microscopy and transmission electron microscopy, and X-ray diffraction was used to characterize the texture evolution processes. The results showed that as compared to conventional hot rolling process, the warm rolling has led to the refined and homogeneous microstructure and uniform recrystallization texture along γ-fiber in final sheets, indicating that the finish rolling at relatively low temperatures can be the effective way to improve significantly the formability of final sheets.