The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large de...The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.展开更多
Thin-slab continuous casting and rolling technology is a process integrating casting and plastic deformation. In this study,targeting actions such as slab deformation and liquid core flows during the process of liquid...Thin-slab continuous casting and rolling technology is a process integrating casting and plastic deformation. In this study,targeting actions such as slab deformation and liquid core flows during the process of liquid core reduction on thin-slab continuous casting, suggests the fluid-solid coupling method should be used to research the characteristic and patterns of slab deformation during the liquid core reduction process, as well as research liquid core backflows. A material model of the slab shell was obtained through the high-temperature compression test of the cast steel. The analysis of the fluid-solid coupling simulation for liquid core reduction shows that slab deformation concentrates on the narrow side due to the existence of the liquid core. Meanwhile,the stress and strain increases with the increase of the reduction rate and slab thickness. The changing trends of stress and strain are identical under various conditions. The results demonstrate that using greater reduction at the upper part of the slab, which has a higher temperature and thinner slab,is beneficial to the quality of the slab. Moreover,the liquid core is extruded as the reduction is implemented. The quantity of the extrusion increases with the increase of reduction rate and the thickness of thinner shell, which leads to fluctuation of the mould level, making the operation more difficult.展开更多
A two-dimensional model was applied to simulate the liquid core reduction (LCR) technology of bloom CC using ANSYS software. The deformation characteristics of bloom under different liquid fraction and reducing amount...A two-dimensional model was applied to simulate the liquid core reduction (LCR) technology of bloom CC using ANSYS software. The deformation characteristics of bloom under different liquid fraction and reducing amount are obtained. The results indicate that the main deformation condition of bloom shell is compressive strain, mainly undertaken by the liquid core, which increases with the enhancement of reducing amount. Solidified shell takes minor deformation. The longitudinal section of bloom appears sunken and the narrow side bulges, which grow serious when the liquid fraction increases.展开更多
基金supported by the National Natural Science Foundation of China(No.52474355)the Liaoning Province Science and Technology Plan Joint Program(Key Research and Development Program Project),China(Nos.2022JH25/10200003 and 2023JH2/101800058).
文摘The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.
文摘Thin-slab continuous casting and rolling technology is a process integrating casting and plastic deformation. In this study,targeting actions such as slab deformation and liquid core flows during the process of liquid core reduction on thin-slab continuous casting, suggests the fluid-solid coupling method should be used to research the characteristic and patterns of slab deformation during the liquid core reduction process, as well as research liquid core backflows. A material model of the slab shell was obtained through the high-temperature compression test of the cast steel. The analysis of the fluid-solid coupling simulation for liquid core reduction shows that slab deformation concentrates on the narrow side due to the existence of the liquid core. Meanwhile,the stress and strain increases with the increase of the reduction rate and slab thickness. The changing trends of stress and strain are identical under various conditions. The results demonstrate that using greater reduction at the upper part of the slab, which has a higher temperature and thinner slab,is beneficial to the quality of the slab. Moreover,the liquid core is extruded as the reduction is implemented. The quantity of the extrusion increases with the increase of reduction rate and the thickness of thinner shell, which leads to fluctuation of the mould level, making the operation more difficult.
文摘A two-dimensional model was applied to simulate the liquid core reduction (LCR) technology of bloom CC using ANSYS software. The deformation characteristics of bloom under different liquid fraction and reducing amount are obtained. The results indicate that the main deformation condition of bloom shell is compressive strain, mainly undertaken by the liquid core, which increases with the enhancement of reducing amount. Solidified shell takes minor deformation. The longitudinal section of bloom appears sunken and the narrow side bulges, which grow serious when the liquid fraction increases.
