Understanding the wear characteristics of coatings on the hot faces of molds is important for extending the service life of molds and improving the quality of continuously cast slabs. First, on the basis of the temperature measured via thermocouples in copper mold plates during the continuous casting of 45# steel with a carbon content of 0.44 wt pct, an inverse calculation model was developed to predict the heat flux between the mold and slab. Second, thermo-mechanical models of the mold and slab were developed separately to analyze the temperature distribution and deformation of the copper mold plates and the slab under practical production conditions with the inversely calculated heat flux. Third, the deformed copper mold plates and solidified shell were extracted, and a contact and wear model was developed on the basis of the Archard model via the UMESHMOTION subroutine. The predicted temperatures of the copper mold plates were compared with those measured by the thermocouples. The predicted wear amount of the mold coating was compared with actual industrial data. The thermal and deformation behaviors of the mold and slab and the wear behavior of the coating were subsequently examined in detail. The results indicated that with increasing distance below the meniscus, the temperature of the hot faces of the mold decreased, but at 25 mm above the mold exit, the temperature increased again because of the absence of cooling water. The maximum deformation of the narrow hot surface and the wide hot surface is 0.21 mm and 0.18 mm, respectively. In the mold, the slab temperature continues to decrease as the slab goes down, and the corner of the solidified shell continues to shrink. At the mold exit, the temperature at the slab corner decreases to 827 °C, and the deformation reaches 3.7 mm. The wear of coating is relatively low in the upper part of the mold because of the very thin shell. Wear became severe in the lower part of the mold, especially in the off-corner region above the exit, under the combined effect of the larger expansion of the mold and the hydrostatic pressure of molten steel. A comparison of Ni–Co and Ni–Co–Al2O3 coatings reveals that the addition of Al2O3 significantly increases the service life of the coating. The maximum wear depths of Ni–Co–Al2O3 and Ni–Co coatings after 400 periods of oscillation are calculated to be 1.551 × 10−4 and 1.842 × 10−4 mm, respectively. With increasing taper amount, the narrow plate contacts the slab more completely, and wear increased.

Numerical Simulation of Contact and Wear Between Deformed Mold and Solidified Shell Based on Archard Model

期刊论文
发表日期：

2025年5月29日

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Hang Zhang,
Weiling Wang,
Chenxu Zhao,
Zhaozhen Cai,
Binzhou Li,
Miaoyong Zhu

摘要

Understanding the wear characteristics of coatings on the hot faces of molds is important for extending the service life of molds and improving the quality of continuously cast slabs. First, on the basis of the temperature measured via thermocouples in copper mold plates during the continuous casting of 45# steel with a carbon content of 0.44 wt pct, an inverse calculation model was developed to predict the heat flux between the mold and slab. Second, thermo-mechanical models of the mold and slab were developed separately to analyze the temperature distribution and deformation of the copper mold plates and the slab under practical production conditions with the inversely calculated heat flux. Third, the deformed copper mold plates and solidified shell were extracted, and a contact and wear model was developed on the basis of the Archard model via the UMESHMOTION subroutine. The predicted temperatures of the copper mold plates were compared with those measured by the thermocouples. The predicted wear amount of the mold coating was compared with actual industrial data. The thermal and deformation behaviors of the mold and slab and the wear behavior of the coating were subsequently examined in detail. The results indicated that with increasing distance below the meniscus, the temperature of the hot faces of the mold decreased, but at 25 mm above the mold exit, the temperature increased again because of the absence of cooling water. The maximum deformation of the narrow hot surface and the wide hot surface is 0.21 mm and 0.18 mm, respectively. In the mold, the slab temperature continues to decrease as the slab goes down, and the corner of the solidified shell continues to shrink. At the mold exit, the temperature at the slab corner decreases to 827 °C, and the deformation reaches 3.7 mm. The wear of coating is relatively low in the upper part of the mold because of the very thin shell. Wear became severe in the lower part of the mold, especially in the off-corner region above the exit, under the combined effect of the larger expansion of the mold and the hydrostatic pressure of molten steel. A comparison of Ni–Co and Ni–Co–Al₂O₃ coatings reveals that the addition of Al₂O₃ significantly increases the service life of the coating. The maximum wear depths of Ni–Co–Al₂O₃ and Ni–Co coatings after 400 periods of oscillation are calculated to be 1.551 × 10⁻⁴ and 1.842 × 10⁻⁴ mm, respectively. With increasing taper amount, the narrow plate contacts the slab more completely, and wear increased.