BN–ZrO_(2)ceramics with different additives such as SiC,Al_(2)O_(3) and MgAl_(2)O_(4) were fabricated by hot pressing sintering process to study sintering properties and corrosion resistance by the rotary immersion m...BN–ZrO_(2)ceramics with different additives such as SiC,Al_(2)O_(3) and MgAl_(2)O_(4) were fabricated by hot pressing sintering process to study sintering properties and corrosion resistance by the rotary immersion molten steel test.The results showed that SiC,Al_(2)O_(3) and MgAl_(2)O_(4) can improve the sintering properties of BN–ZrO_(2)ceramics;especially,the introduction of SiC can significantly improve the hardness of the material;thus,the above compounds will help to improve the wear resistance of BN–ZrO_(2)ceramics.The exposed oxide layer is in contact with molten steel and forms liquid phase after BN oxidation and B_(2)O_(3) volatilization,additives can significantly affect the properties of liquid phase,and m-ZrO_(2)grains are sintered and grown by dissolution–precipitation mechanism by liquid phase.Consequently,Al_(2)O_(3) and MgAl_(2)O_(4) are more conducive to the formation of working layer with solid skeleton,which determines the corrosion resistance of BN–ZrO_(2)ceramics.展开更多
Microstructure evolution, dynamic recrystallization, high temperature oxidation and hot ductility of 1.4 % Si non-oriented electrical steel sheets were investigated to reduce edge cracking. The causes of cracking were...Microstructure evolution, dynamic recrystallization, high temperature oxidation and hot ductility of 1.4 % Si non-oriented electrical steel sheets were investigated to reduce edge cracking. The causes of cracking were found to be coarse as-cast microstructure, grain boundary oxidation in reheating furnace, lack of dynamic recrystallization during hot rolling and increase of temperature, resulting in reduced hot ductility in strip edge region. Countermeas- ures against the edge crack are proposed accordingly. Lowering reheating temperature and reducing holding time re- duced oxidation and decarburization. Hot charging temperature was increased to decrease reheating temperature. And using an edger can refine microstructure in strip edge region. Finally, edge heater can be added to increase edge re- gion formability by inducing dynamic reerystallization and ductility by increasing temperature.展开更多
基金The authors gratefully acknowledge the support of National Natural Science Foundation of China(51932008 and 51772277)Central China Thousand Talents Project(204200510011).
文摘BN–ZrO_(2)ceramics with different additives such as SiC,Al_(2)O_(3) and MgAl_(2)O_(4) were fabricated by hot pressing sintering process to study sintering properties and corrosion resistance by the rotary immersion molten steel test.The results showed that SiC,Al_(2)O_(3) and MgAl_(2)O_(4) can improve the sintering properties of BN–ZrO_(2)ceramics;especially,the introduction of SiC can significantly improve the hardness of the material;thus,the above compounds will help to improve the wear resistance of BN–ZrO_(2)ceramics.The exposed oxide layer is in contact with molten steel and forms liquid phase after BN oxidation and B_(2)O_(3) volatilization,additives can significantly affect the properties of liquid phase,and m-ZrO_(2)grains are sintered and grown by dissolution–precipitation mechanism by liquid phase.Consequently,Al_(2)O_(3) and MgAl_(2)O_(4) are more conducive to the formation of working layer with solid skeleton,which determines the corrosion resistance of BN–ZrO_(2)ceramics.
文摘Microstructure evolution, dynamic recrystallization, high temperature oxidation and hot ductility of 1.4 % Si non-oriented electrical steel sheets were investigated to reduce edge cracking. The causes of cracking were found to be coarse as-cast microstructure, grain boundary oxidation in reheating furnace, lack of dynamic recrystallization during hot rolling and increase of temperature, resulting in reduced hot ductility in strip edge region. Countermeas- ures against the edge crack are proposed accordingly. Lowering reheating temperature and reducing holding time re- duced oxidation and decarburization. Hot charging temperature was increased to decrease reheating temperature. And using an edger can refine microstructure in strip edge region. Finally, edge heater can be added to increase edge re- gion formability by inducing dynamic reerystallization and ductility by increasing temperature.
