The hot deformation behavior of F6NM stainless steel was investigated by hot compression test in a Gleeble-1500D thermal-mechanical simulator. The flow strain-stress curves were obtained and the corresponding metallog...The hot deformation behavior of F6NM stainless steel was investigated by hot compression test in a Gleeble-1500D thermal-mechanical simulator. The flow strain-stress curves were obtained and the corresponding metallographic observation of this steel under different deformation conditions was also carried out. This steel exhibi- ted dynamic recrystallization （DRX） in the temperature range of 1 273- 1473 K and the strain rate range of 0.01- 0.1 s^-1. The activation energy for hot deformation was determined to be 457.91 kJ/mol, and the hot deformation equations were also established. The flow instability zone was determined and could be divided into two regions. The first one was located in the temperature range of 1 173- 1 348 K and the strain rate range of 0. 056-10 s^-1 , while the second one is in the temperature range of 1398-1448 K and the strain rate range of 1.25-10 s^-1. In the end, the optimum conditions for hot working were provided.展开更多
Hot deformation behavior of an Fe-20Mn-19Cr-0.5C-0.6N high-nitrogen austenitic steel has been studied by isothermal compression tests in deformation temperature range of 800-1200℃ and strain rate range of 0.01-10 s^-...Hot deformation behavior of an Fe-20Mn-19Cr-0.5C-0.6N high-nitrogen austenitic steel has been studied by isothermal compression tests in deformation temperature range of 800-1200℃ and strain rate range of 0.01-10 s^-1. Results indicate that the Fe-20Mn-19Cr-0.5C-0.6N steel has high deformation resistance due to strong hindering effect on dislocation moving by nitrogen-induced lattice misfit. The twinning-induced plasticity effect is gradually suppressed with the increase in deformation temperature, and high-temperature plastic deformation mechanism by twinning is gradually replaced by dislocation planar slip. The deformation resistance is up to 343 MPa at deformation conditions of (1000 ℃, 0.01 s^-1), which is over 100 MPa higher than that in martensitic steel and 50 MPa higher than that in austenitic steel. Besides, value of deformation activation energy for the Fe-20Mn-19Cr-0.6N steel is up to 784 kJ mol^-1. Power dissipation efficiency is lower than 0.13, while hot processing map exhibits a very wide range of working area. The optimum hot working process obtains at deformation temperature range of 950-1200℃ and strain rate range of 0.01-10 s^-1, when deformation acti-vation energy is less than 662.6 kJ mol^-1, power dissipation efficiency exceeds 0.22, dynamic recrystallization fraction is over 46.1% and microstructures are without instable characteristics.展开更多
基金Item Sponsored by National Science and Technology Major Project of Large-scale Advanced Pressurized Water Reactor of China(20112X06004-016)
文摘The hot deformation behavior of F6NM stainless steel was investigated by hot compression test in a Gleeble-1500D thermal-mechanical simulator. The flow strain-stress curves were obtained and the corresponding metallographic observation of this steel under different deformation conditions was also carried out. This steel exhibi- ted dynamic recrystallization （DRX） in the temperature range of 1 273- 1473 K and the strain rate range of 0.01- 0.1 s^-1. The activation energy for hot deformation was determined to be 457.91 kJ/mol, and the hot deformation equations were also established. The flow instability zone was determined and could be divided into two regions. The first one was located in the temperature range of 1 173- 1 348 K and the strain rate range of 0. 056-10 s^-1 , while the second one is in the temperature range of 1398-1448 K and the strain rate range of 1.25-10 s^-1. In the end, the optimum conditions for hot working were provided.
基金This work was financially supported by the National Natural Science Foundation of China (NSFC) under project No. 51301042The authors would like to thank Dr. Nan Li of Central Iron and Steel Research Institute (CISRI) for the help of isothermal compression tests.
文摘Hot deformation behavior of an Fe-20Mn-19Cr-0.5C-0.6N high-nitrogen austenitic steel has been studied by isothermal compression tests in deformation temperature range of 800-1200℃ and strain rate range of 0.01-10 s^-1. Results indicate that the Fe-20Mn-19Cr-0.5C-0.6N steel has high deformation resistance due to strong hindering effect on dislocation moving by nitrogen-induced lattice misfit. The twinning-induced plasticity effect is gradually suppressed with the increase in deformation temperature, and high-temperature plastic deformation mechanism by twinning is gradually replaced by dislocation planar slip. The deformation resistance is up to 343 MPa at deformation conditions of (1000 ℃, 0.01 s^-1), which is over 100 MPa higher than that in martensitic steel and 50 MPa higher than that in austenitic steel. Besides, value of deformation activation energy for the Fe-20Mn-19Cr-0.6N steel is up to 784 kJ mol^-1. Power dissipation efficiency is lower than 0.13, while hot processing map exhibits a very wide range of working area. The optimum hot working process obtains at deformation temperature range of 950-1200℃ and strain rate range of 0.01-10 s^-1, when deformation acti-vation energy is less than 662.6 kJ mol^-1, power dissipation efficiency exceeds 0.22, dynamic recrystallization fraction is over 46.1% and microstructures are without instable characteristics.
