The refractory composition of submerged entry nozzles(SEN)critically governs interfacial reactions,which in turn determines the onset of clogging.The interfacial reactions between two Al_(2)O_(3)-C refractories with 8...The refractory composition of submerged entry nozzles(SEN)critically governs interfacial reactions,which in turn determines the onset of clogging.The interfacial reactions between two Al_(2)O_(3)-C refractories with 8.7 and 1.7 Al_(2)O_(3)/SiO_(2)ratios and Al-killed steel were studied through laboratory experiments.The flow of molten steel relative to the inner wall of the SEN was simulated by rotating a refractory rod in high-temperature molten steel.For the Al_(2)O_(3)-C refractory with an 8.7 Al_(2)O_(3)/SiO_(2)ratio,an Al_(2)O_(3)reaction layer was formed at the steel/refractory interface as the reaction progressed,which initially grew to 780μm before thinning to 470μm.Concurrently,the refractory surface became entirely coated with both clustered and plate-shaped Al_(2)O_(3)inclusions following 120 min of reaction.For the Al_(2)O_(3)-C refractory with a 1.7 Al_(2)O_(3)/SiO_(2)ratio,a continuous Si-Al-Fe-O liquid reaction layer was generated at the steel/refractory interface,which significantly impeded the physicochemical interactions between the molten steel and refractory.The composition of the reaction layer evolved sequentially from the Si-Al-Fe-O liquid phase to the Si-Al-O solid phases with the increasing reaction time.After 120 min,the refractory surface became fully coated with clustered Al_(2)O_(3)inclusions.Compared to the Al_(2)O_(3)-C refractory with a 1.7 Al_(2)O_(3)/SiO_(2)ratio,the Al_(2)O_(3)-C refractory with an 8.7 Al_(2)O_(3)/SiO_(2)ratio was more likely to capture Al_(2)O_(3)inclusions in the steel during its contact with Al-killed steel.The current experiment results indicate that in Al-killed steel continuous casting operations,Al_(2)O_(3)-C-based SEN with an 8.7 Al_(2)O_(3)/SiO_(2)ratio should have a higher clogging potential than Al_(2)O_(3)-C-based SEN with a 1.7 Al_(2)O_(3)/SiO_(2)ratio under equivalent casting conditions.展开更多
基金support from the National Key R&D Program(Grant No.2023YFB3709901)the National Natural Science Foundation of China(Grant Nos.U22A20171,52474366 and 52404335)the High Steel Center(HSC)at North China University of Technology.
文摘The refractory composition of submerged entry nozzles(SEN)critically governs interfacial reactions,which in turn determines the onset of clogging.The interfacial reactions between two Al_(2)O_(3)-C refractories with 8.7 and 1.7 Al_(2)O_(3)/SiO_(2)ratios and Al-killed steel were studied through laboratory experiments.The flow of molten steel relative to the inner wall of the SEN was simulated by rotating a refractory rod in high-temperature molten steel.For the Al_(2)O_(3)-C refractory with an 8.7 Al_(2)O_(3)/SiO_(2)ratio,an Al_(2)O_(3)reaction layer was formed at the steel/refractory interface as the reaction progressed,which initially grew to 780μm before thinning to 470μm.Concurrently,the refractory surface became entirely coated with both clustered and plate-shaped Al_(2)O_(3)inclusions following 120 min of reaction.For the Al_(2)O_(3)-C refractory with a 1.7 Al_(2)O_(3)/SiO_(2)ratio,a continuous Si-Al-Fe-O liquid reaction layer was generated at the steel/refractory interface,which significantly impeded the physicochemical interactions between the molten steel and refractory.The composition of the reaction layer evolved sequentially from the Si-Al-Fe-O liquid phase to the Si-Al-O solid phases with the increasing reaction time.After 120 min,the refractory surface became fully coated with clustered Al_(2)O_(3)inclusions.Compared to the Al_(2)O_(3)-C refractory with a 1.7 Al_(2)O_(3)/SiO_(2)ratio,the Al_(2)O_(3)-C refractory with an 8.7 Al_(2)O_(3)/SiO_(2)ratio was more likely to capture Al_(2)O_(3)inclusions in the steel during its contact with Al-killed steel.The current experiment results indicate that in Al-killed steel continuous casting operations,Al_(2)O_(3)-C-based SEN with an 8.7 Al_(2)O_(3)/SiO_(2)ratio should have a higher clogging potential than Al_(2)O_(3)-C-based SEN with a 1.7 Al_(2)O_(3)/SiO_(2)ratio under equivalent casting conditions.
基金supported by the National Natural Science Foundation of China(No.52165050)the Natural Science Foundation of Jiangxi Province,China(No.20181BAB206027).
