In order to solve the problem of the high surface longitudinal crack ratio of heavy peritectic steel slabs produced by the No. 3 continuous caster at Baosteel,the physical properties of the original mold flux and the ...In order to solve the problem of the high surface longitudinal crack ratio of heavy peritectic steel slabs produced by the No. 3 continuous caster at Baosteel,the physical properties of the original mold flux and the optimized mold flux were compared in a comprehensive way by using analytical measures, such as a slag film heat-flow simulator, a thermowire molten flux crystallization tester and an X-ray diffractometer in the laboratory. The results reveal that one of the major reasons for the cracks is the poor heat transfer ability of the original mold flux. However, the optimized mold flux with a high basicity features a high crystallizing rate,low crystallization temperature and low heat-flow density. Therefore, the optimized mold flux is more suitable for casting peritectic steel by the heavy slab continuous caster. The test results show that the slabs produced by using the optimized mold flux had no surface longitudinal crack in four test casts, while the surface longitudinal crack ratio of the slabs produced by using the original mold flux was 5%. The optimized mold flux can effectively prevent slab surface longitudinal cracks from occurring.展开更多
Continuous casting has evolved as the most important production process in the steel industry.Today it counts for about 95% of the world’s steel production.Parallel to its rising significance,the process technologies...Continuous casting has evolved as the most important production process in the steel industry.Today it counts for about 95% of the world’s steel production.Parallel to its rising significance,the process technologies have been enhanced in yield,productivity and-in particular quality of semi-finished products has been improved close to the realm of possibility.Further optimizing the product quality beyond the present status has to put the whole manufacturing route from hot metal and/or steel melting through refining to continuous casting under integrated control.Prerequisite for the production of HSLA steel grades of the highest standard are clean steel,internal soundness and defect-free slab surfaces.In this context a brief look is cast on the recent trend of process technology in casting "thick slabs" for extra-heavy plate production.展开更多
Study on cleanliness of high quality steels in 100t basic oxygen furnace was carried out by "Hot Metal Desulphurization-Basic Oxygen Furnace-Ladle Furnace Refining-RH Refining-Continuous Casting" process. Hi...Study on cleanliness of high quality steels in 100t basic oxygen furnace was carried out by "Hot Metal Desulphurization-Basic Oxygen Furnace-Ladle Furnace Refining-RH Refining-Continuous Casting" process. High-quality low-carbon ultra thick slabs were produced with 0.04%≤wC≤0.08%, wS≤0.002%, wP≤0.008%, wN≤0.004%, wH≤ 0.0002%, wT[O] ≤0.0015%. A series of key technologies for content control of carbon, phosphorus, sulfur, nitrogen, hydrogen and inclusions were determined, which has laid a foundation for the development of the high-degree steel.展开更多
文摘In order to solve the problem of the high surface longitudinal crack ratio of heavy peritectic steel slabs produced by the No. 3 continuous caster at Baosteel,the physical properties of the original mold flux and the optimized mold flux were compared in a comprehensive way by using analytical measures, such as a slag film heat-flow simulator, a thermowire molten flux crystallization tester and an X-ray diffractometer in the laboratory. The results reveal that one of the major reasons for the cracks is the poor heat transfer ability of the original mold flux. However, the optimized mold flux with a high basicity features a high crystallizing rate,low crystallization temperature and low heat-flow density. Therefore, the optimized mold flux is more suitable for casting peritectic steel by the heavy slab continuous caster. The test results show that the slabs produced by using the optimized mold flux had no surface longitudinal crack in four test casts, while the surface longitudinal crack ratio of the slabs produced by using the original mold flux was 5%. The optimized mold flux can effectively prevent slab surface longitudinal cracks from occurring.
文摘Continuous casting has evolved as the most important production process in the steel industry.Today it counts for about 95% of the world’s steel production.Parallel to its rising significance,the process technologies have been enhanced in yield,productivity and-in particular quality of semi-finished products has been improved close to the realm of possibility.Further optimizing the product quality beyond the present status has to put the whole manufacturing route from hot metal and/or steel melting through refining to continuous casting under integrated control.Prerequisite for the production of HSLA steel grades of the highest standard are clean steel,internal soundness and defect-free slab surfaces.In this context a brief look is cast on the recent trend of process technology in casting "thick slabs" for extra-heavy plate production.
文摘Study on cleanliness of high quality steels in 100t basic oxygen furnace was carried out by "Hot Metal Desulphurization-Basic Oxygen Furnace-Ladle Furnace Refining-RH Refining-Continuous Casting" process. High-quality low-carbon ultra thick slabs were produced with 0.04%≤wC≤0.08%, wS≤0.002%, wP≤0.008%, wN≤0.004%, wH≤ 0.0002%, wT[O] ≤0.0015%. A series of key technologies for content control of carbon, phosphorus, sulfur, nitrogen, hydrogen and inclusions were determined, which has laid a foundation for the development of the high-degree steel.
