Purging plugs installed in the bottom of steel ladles are widely used for the secondary refining of high quality steel grades.The dynamic service conditions and temperature gradients caused by the cold inert gas blown...Purging plugs installed in the bottom of steel ladles are widely used for the secondary refining of high quality steel grades.The dynamic service conditions and temperature gradients caused by the cold inert gas blown through the plug during stirring create a strong thermal shock impact on the materials.This can affect its service life and restrict the safety and efficiency of steel making if the plug fails during use.In this work,the influence of the particle size distribution (PSD) and amount of reactive alumina on the sintering behavior of ultra-low cement bonded corundum-spinel based castables was investigated on lab scale.The relationship between sintering reactivity of matrix and thermal shock resistance of castables was evaluated in detail.Results show that the sintering of castables can be intensified by using finer reactive alumina.However,excessive sintering of the castable through finer reactive alumina is negative for thermal shock resistance.The microstructure characterization reveals that castables with more intense sintering show denser matrix structure,which is less effective in hampering crack propagation and therefore results in decline of their thermal shock resistance.展开更多
For the proper use of micropowders in castables,slurries and fired samples were prepared with two kinds of corundumspinel micropowders(D and G).The effects of the solid content and disperser WSM-R1 on the rheological ...For the proper use of micropowders in castables,slurries and fired samples were prepared with two kinds of corundumspinel micropowders(D and G).The effects of the solid content and disperser WSM-R1 on the rheological properties of the slurries were studied.The sintering properties and the slag corrosion resistance of the fired samples were also researched.The results show that:the slurries all show pseudoplastic rheological characteristics.With the same solid content,the slurry with micropowder G has higher initial viscosity than that with micropowder D.Disperser WSM-R1 significantly reduces the initial viscosity of the two slurries and plays a more obvious dispersing effect on the slurry with micropowder G.The fired sample with micropowder G has higher bulk density,lower apparent porosity and better corrosion resistance than that with micropowder D.展开更多
Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel （ MgAl2O4 ） ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted u...Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel （ MgAl2O4 ） ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance.展开更多
The corundum - spinel castables were prepared by six kinds of tabular corundum, as aggregates, respective- ly, and their linear change rate on heating, apparent porosity, bulk density, cold modulus of rupture, coht cr...The corundum - spinel castables were prepared by six kinds of tabular corundum, as aggregates, respective- ly, and their linear change rate on heating, apparent porosity, bulk density, cold modulus of rupture, coht crushing strength, hot modulus of rupture and thermal shock resistance were compared and studied. The results show that： 1） the six tabular corundum materials have similar main chemical composition but their physical properties vary for the different technical procedures which result in different properties of castables ; 2 ） the optimal properties of corundum - spinel castables corre- spotut to different tabular corundum types, so the corundum type shall be selected according to the application of the castables.展开更多
为了满足生产低碳钢和超低碳钢的技术要求,以棕刚玉、板状刚玉、电熔镁铝尖晶石粉为原料,电熔镁砂粉和α-氧化铝微粉为添加剂,络合镁铝溶胶为结合剂,研制出了机压成型免烧刚玉-尖晶石无碳砖,并进行了实验。试验结果表明:当电熔镁砂粉和...为了满足生产低碳钢和超低碳钢的技术要求,以棕刚玉、板状刚玉、电熔镁铝尖晶石粉为原料,电熔镁砂粉和α-氧化铝微粉为添加剂,络合镁铝溶胶为结合剂,研制出了机压成型免烧刚玉-尖晶石无碳砖,并进行了实验。试验结果表明:当电熔镁砂粉和α-氧化铝微粉加入量分别为3%和8%时,试验砖的性能最佳。该砖在太钢90 t LF钢包熔池及包底部位使用,其寿命达到105炉。展开更多
基金the National Natural Science Foundation of China(51572244 and U1604252)for supporting this work
文摘Purging plugs installed in the bottom of steel ladles are widely used for the secondary refining of high quality steel grades.The dynamic service conditions and temperature gradients caused by the cold inert gas blown through the plug during stirring create a strong thermal shock impact on the materials.This can affect its service life and restrict the safety and efficiency of steel making if the plug fails during use.In this work,the influence of the particle size distribution (PSD) and amount of reactive alumina on the sintering behavior of ultra-low cement bonded corundum-spinel based castables was investigated on lab scale.The relationship between sintering reactivity of matrix and thermal shock resistance of castables was evaluated in detail.Results show that the sintering of castables can be intensified by using finer reactive alumina.However,excessive sintering of the castable through finer reactive alumina is negative for thermal shock resistance.The microstructure characterization reveals that castables with more intense sintering show denser matrix structure,which is less effective in hampering crack propagation and therefore results in decline of their thermal shock resistance.
基金fully funded by National Natural Science Foundation of China and Youth Fund Projects(51802235)
文摘For the proper use of micropowders in castables,slurries and fired samples were prepared with two kinds of corundumspinel micropowders(D and G).The effects of the solid content and disperser WSM-R1 on the rheological properties of the slurries were studied.The sintering properties and the slag corrosion resistance of the fired samples were also researched.The results show that:the slurries all show pseudoplastic rheological characteristics.With the same solid content,the slurry with micropowder G has higher initial viscosity than that with micropowder D.Disperser WSM-R1 significantly reduces the initial viscosity of the two slurries and plays a more obvious dispersing effect on the slurry with micropowder G.The fired sample with micropowder G has higher bulk density,lower apparent porosity and better corrosion resistance than that with micropowder D.
基金The National Natural Science Foundation of China(Grant No.51302201)
文摘Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel （ MgAl2O4 ） ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance.
文摘The corundum - spinel castables were prepared by six kinds of tabular corundum, as aggregates, respective- ly, and their linear change rate on heating, apparent porosity, bulk density, cold modulus of rupture, coht crushing strength, hot modulus of rupture and thermal shock resistance were compared and studied. The results show that： 1） the six tabular corundum materials have similar main chemical composition but their physical properties vary for the different technical procedures which result in different properties of castables ; 2 ） the optimal properties of corundum - spinel castables corre- spotut to different tabular corundum types, so the corundum type shall be selected according to the application of the castables.
文摘为了满足生产低碳钢和超低碳钢的技术要求,以棕刚玉、板状刚玉、电熔镁铝尖晶石粉为原料,电熔镁砂粉和α-氧化铝微粉为添加剂,络合镁铝溶胶为结合剂,研制出了机压成型免烧刚玉-尖晶石无碳砖,并进行了实验。试验结果表明:当电熔镁砂粉和α-氧化铝微粉加入量分别为3%和8%时,试验砖的性能最佳。该砖在太钢90 t LF钢包熔池及包底部位使用,其寿命达到105炉。
