Corrosion resistance and penetration resistance of MgO- CaO materials with different CaO contents( 22%,42%,49%,53%,in mass) to refining AOD slag or VOD slag were investigated using static crucible technique by visual ...Corrosion resistance and penetration resistance of MgO- CaO materials with different CaO contents( 22%,42%,49%,53%,in mass) to refining AOD slag or VOD slag were investigated using static crucible technique by visual observation,SEM and XRD. The corrosion resistance and penetration resistance of specimens decrease with the increase of CaO content. This may be caused by the formation of C3S and C2S during the reactions between specimens and the slag. The formed C3S and C2S can restrain the further penetration to the matrix. The higher the CaO content,the more the C2S or C3S formed,the lower the porosity of the specimens,and the lower the penetration depth and corrosion rate. The corrosion resistance to AOD slag is better than that to VOD slag,because the reaction between AOD slag and the matrix is slighter than that between VOD slag and the matrix.展开更多
The structure of SEN and upper nozzles was optimized and simulated. Relevant trials were conducted on site during thecasting of Al-killed steel. These optimizations effectively solve the nozzle clogging and reduce the...The structure of SEN and upper nozzles was optimized and simulated. Relevant trials were conducted on site during thecasting of Al-killed steel. These optimizations effectively solve the nozzle clogging and reduce the defects of the casting slab.展开更多
The paper analyzed the recycle condit ion and developing trend of used refractories China and other countries, includi ng research achievements of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C bricks...The paper analyzed the recycle condit ion and developing trend of used refractories China and other countries, includi ng research achievements of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C bricks, Al2O3-SiC-C castable and MgO-C r2O3 bricks. Recycled refractories exhibit the same or even better p roperties as compared with the original. In addition, prospects for recycle of u sed refractories are also discusseded.展开更多
Effects of operation conditions such as ladle temperature, remaining time of molten steel,slag basicity,slag oxidation,slag viscosity,vacuum treatment,ultra-high temperature,gas blowing and stirring,intermittent opera...Effects of operation conditions such as ladle temperature, remaining time of molten steel,slag basicity,slag oxidation,slag viscosity,vacuum treatment,ultra-high temperature,gas blowing and stirring,intermittent operation ,and different refining equipment on service life of ladle lining refractories were researched.The following conclusions are drawn;(1) molten steel temperature rising, remaining time prolonging,slag oxidation ability enhancing,slag viscosity and basicity decreasing can accelerate the corrosion of ladle lining;(2) ultra-high temperature and vacuum treatment of ladle not only accelerate the fusion corrosion of ladle lining,but also make the carbon containing refractories react forming gases leading to more corrosion,so carbon containing refractories are not suitable for the smelting conditions of long term vacuum treatment and ultra-high temperature,especially carbon containing refractories added with conventional additives such as Al and Si powders;(3 ) argon blowing does not accelerate the corrosion of ladle lining obviously,but oxygen blowing does;(4) the corrosion degree of refractories varies with the refining equipment,and the service life of ladle lining decreases according to a certain proportion with the refining ratio increasing.展开更多
Monolithic stoppers play a very important role in continuous casting( short for CC). Sometimes,the stopper slag line is seriously eroded and broken,CC has to pause. The research shows that there are three main reasons...Monolithic stoppers play a very important role in continuous casting( short for CC). Sometimes,the stopper slag line is seriously eroded and broken,CC has to pause. The research shows that there are three main reasons which bring severe erosion of monolithic stopper slag line. Firstly,much Fe_2O_3 and MnO in slag react with carbon( C) in the stopper,C is gradually eroded and erosion resistance of the stopper greatly weakens. Secondly,F increase in tundish covering flux will quicken erosion of the stopper slag line. Thirdly, High LOI of tundish covering flux also makes erosion of the stopper slag line speed up. On one hand,CaCO_3 in tundish covering flux decomposes and brings CO_2; on the other hand,minerals with water in tundish covering flux decompose at high temperatures and bring water vapor.Then CO_2 and water vapor react with C in the stopper,C is gradually eroded,aggravating the erosion.展开更多
文摘Corrosion resistance and penetration resistance of MgO- CaO materials with different CaO contents( 22%,42%,49%,53%,in mass) to refining AOD slag or VOD slag were investigated using static crucible technique by visual observation,SEM and XRD. The corrosion resistance and penetration resistance of specimens decrease with the increase of CaO content. This may be caused by the formation of C3S and C2S during the reactions between specimens and the slag. The formed C3S and C2S can restrain the further penetration to the matrix. The higher the CaO content,the more the C2S or C3S formed,the lower the porosity of the specimens,and the lower the penetration depth and corrosion rate. The corrosion resistance to AOD slag is better than that to VOD slag,because the reaction between AOD slag and the matrix is slighter than that between VOD slag and the matrix.
文摘The structure of SEN and upper nozzles was optimized and simulated. Relevant trials were conducted on site during thecasting of Al-killed steel. These optimizations effectively solve the nozzle clogging and reduce the defects of the casting slab.
文摘The paper analyzed the recycle condit ion and developing trend of used refractories China and other countries, includi ng research achievements of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C bricks, Al2O3-SiC-C castable and MgO-C r2O3 bricks. Recycled refractories exhibit the same or even better p roperties as compared with the original. In addition, prospects for recycle of u sed refractories are also discusseded.
文摘Effects of operation conditions such as ladle temperature, remaining time of molten steel,slag basicity,slag oxidation,slag viscosity,vacuum treatment,ultra-high temperature,gas blowing and stirring,intermittent operation ,and different refining equipment on service life of ladle lining refractories were researched.The following conclusions are drawn;(1) molten steel temperature rising, remaining time prolonging,slag oxidation ability enhancing,slag viscosity and basicity decreasing can accelerate the corrosion of ladle lining;(2) ultra-high temperature and vacuum treatment of ladle not only accelerate the fusion corrosion of ladle lining,but also make the carbon containing refractories react forming gases leading to more corrosion,so carbon containing refractories are not suitable for the smelting conditions of long term vacuum treatment and ultra-high temperature,especially carbon containing refractories added with conventional additives such as Al and Si powders;(3 ) argon blowing does not accelerate the corrosion of ladle lining obviously,but oxygen blowing does;(4) the corrosion degree of refractories varies with the refining equipment,and the service life of ladle lining decreases according to a certain proportion with the refining ratio increasing.
文摘Monolithic stoppers play a very important role in continuous casting( short for CC). Sometimes,the stopper slag line is seriously eroded and broken,CC has to pause. The research shows that there are three main reasons which bring severe erosion of monolithic stopper slag line. Firstly,much Fe_2O_3 and MnO in slag react with carbon( C) in the stopper,C is gradually eroded and erosion resistance of the stopper greatly weakens. Secondly,F increase in tundish covering flux will quicken erosion of the stopper slag line. Thirdly, High LOI of tundish covering flux also makes erosion of the stopper slag line speed up. On one hand,CaCO_3 in tundish covering flux decomposes and brings CO_2; on the other hand,minerals with water in tundish covering flux decompose at high temperatures and bring water vapor.Then CO_2 and water vapor react with C in the stopper,C is gradually eroded,aggravating the erosion.
