The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The...The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The results indicate that during cooling process, theamount of segregated boron on grain boundary firstly increases fast, then enters a comparativelyeven increasing stage and increases rapidly again at the third stage. The details of each stagevaried with cooling rate are explained. When the segregation develops to a certain degree, thesegregated boron atoms transform from solute status to precipitate status.展开更多
Different densities and configurations of crystal defects were obtained in anaustenitic Fe-30 percent Ni alloy and an ultra low carbon bainitic (ULCB) alloy by undergoingdifferent deformations and annealing treatments...Different densities and configurations of crystal defects were obtained in anaustenitic Fe-30 percent Ni alloy and an ultra low carbon bainitic (ULCB) alloy by undergoingdifferent deformations and annealing treatments at high temperatures. Boron segregation on grainboundaries and subgrain boundaries during air-cooling were revealed by means of the particletracking autoradiography technique. It is found that non-equilibrium segregation is resisted indeformed grains after recovery and polygonization, boron-depleted zones seem to be quite clear inrecrystallized grains than those in deformed original grains during cooling. Subgrain boundaries andpolygonized dislocation cells have a significant effect on non-equilibrium boron segregation duringthe air-cooling. The results implicates that dislocation configuration is a more important factoraffecting boron segregation at grain boundaries rather that the density of defects itself in thegrain.展开更多
The moving boundary non-equilibrium segregation duringrecrystallization and the influence of pre-deformation in Fe-30/100Ni alloy at 1000 deg. C was investigated by the PTA(particle trackingautoradiography)technique, ...The moving boundary non-equilibrium segregation duringrecrystallization and the influence of pre-deformation in Fe-30/100Ni alloy at 1000 deg. C was investigated by the PTA(particle trackingautoradiography)technique, optical and electron microscopy. The re-Sults indicated that intensity of boron segregation on movingboundary after different deformation is concerned with thepre-deformation Degree and the moving speed of the boundary. TheTEM(transmission electron microscopy(result showed that thedislocation density Nearby the moving boundary increase obviously.The phenomena are discussed by the widening grain boundary mechanism.展开更多
基金This work was financially supported by the Projects of Development of the State Key Fundamental Research(National 973 Project)(No.G19980601507).]
文摘The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The results indicate that during cooling process, theamount of segregated boron on grain boundary firstly increases fast, then enters a comparativelyeven increasing stage and increases rapidly again at the third stage. The details of each stagevaried with cooling rate are explained. When the segregation develops to a certain degree, thesegregated boron atoms transform from solute status to precipitate status.
基金This work was financially supported by the National Natural Science Foundation of China(No.59291000).
文摘Different densities and configurations of crystal defects were obtained in anaustenitic Fe-30 percent Ni alloy and an ultra low carbon bainitic (ULCB) alloy by undergoingdifferent deformations and annealing treatments at high temperatures. Boron segregation on grainboundaries and subgrain boundaries during air-cooling were revealed by means of the particletracking autoradiography technique. It is found that non-equilibrium segregation is resisted indeformed grains after recovery and polygonization, boron-depleted zones seem to be quite clear inrecrystallized grains than those in deformed original grains during cooling. Subgrain boundaries andpolygonized dislocation cells have a significant effect on non-equilibrium boron segregation duringthe air-cooling. The results implicates that dislocation configuration is a more important factoraffecting boron segregation at grain boundaries rather that the density of defects itself in thegrain.
基金financially supported by the National Natural Science foundation of China (No.59291000).
文摘The moving boundary non-equilibrium segregation duringrecrystallization and the influence of pre-deformation in Fe-30/100Ni alloy at 1000 deg. C was investigated by the PTA(particle trackingautoradiography)technique, optical and electron microscopy. The re-Sults indicated that intensity of boron segregation on movingboundary after different deformation is concerned with thepre-deformation Degree and the moving speed of the boundary. TheTEM(transmission electron microscopy(result showed that thedislocation density Nearby the moving boundary increase obviously.The phenomena are discussed by the widening grain boundary mechanism.
