Dynamic recrystallization and precipitation in high manganese austenitic stainless steel during hot compression
来源期刊：International Journal of Minerals Metallurgy and Materials2014年第1期
论文作者：Shahab Kazemi Golam Ebrahimi Alireza Maldar
文章页码：36 - 45
摘 要：Dynamic recrystallization and precipitation in a high manganese austenitic stainless steel were investigated by hot compression tests over temperatures of 950-1150°C at strain rates of 0.001 s-1-1 s-1.All the flow curves within the studied deformation regimes were typical of dynamic recrystallization.A window was constructed to determine the value of apparent activation energy as a function of strain rate and deformation temperature.The kinetics of dynamic recrystallization was analyzed using the Avrami kinetics equation.A range of apparent activation energy for hot deformation from 303 kJ/mol to 477 kJ/mol is obtained at different deformation regimes.Microscopic characterization confirms that under a certain deformation condition（medium Zener-Hollomon parameter（Z） values）,dynamic recrystallization appears at first,but large particles can not inhibit the recrystallization.At low or high Z values,dynamic recrystallization may occur before dynamic precipitation and proceeds faster.In both cases,secondary phase precipitation is observed along prior austenite grain boundaries.Stress relaxation tests at the same deformation temperatures also confirm the possibility of dynamic precipitation.Unexpectedly,the Avrami’s exponent value increases with the increase of Z value.It is associated with the priority of dynamic recrystallization to dynamic precipitation at higher Z values.
Shahab Kazemi2，Golam Ebrahimi3，Alireza Maldar3
2. Department of Materials Engineering,Faculty of Engineering,Bu Ali Sina University3. Department of Materials and Polymer Engineering,Hakim Sabzevari University
摘 要：Dynamic recrystallization and precipitation in a high manganese austenitic stainless steel were investigated by hot compression tests over temperatures of 950-1150°C at strain rates of 0.001 s-1-1 s-1.All the flow curves within the studied deformation regimes were typical of dynamic recrystallization.A window was constructed to determine the value of apparent activation energy as a function of strain rate and deformation temperature.The kinetics of dynamic recrystallization was analyzed using the Avrami kinetics equation.A range of apparent activation energy for hot deformation from 303 kJ/mol to 477 kJ/mol is obtained at different deformation regimes.Microscopic characterization confirms that under a certain deformation condition（medium Zener-Hollomon parameter（Z） values）,dynamic recrystallization appears at first,but large particles can not inhibit the recrystallization.At low or high Z values,dynamic recrystallization may occur before dynamic precipitation and proceeds faster.In both cases,secondary phase precipitation is observed along prior austenite grain boundaries.Stress relaxation tests at the same deformation temperatures also confirm the possibility of dynamic precipitation.Unexpectedly,the Avrami’s exponent value increases with the increase of Z value.It is associated with the priority of dynamic recrystallization to dynamic precipitation at higher Z values.
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