摘要
气氛含水量对取向硅钢高温退火的工艺质量具有显著影响,因此深入研究了环形炉高温退火中钢带层间含水量的变化规律。分析了钢带涂层中Mg(OH)_2分解速率与升温速率之间的关系,并通过试验证实了内罩内水蒸气分布的均匀性,建立了环形炉高温退火水扩散模型。结果表明,由于钢卷在退火过程中内部的升温速率不均,使得不同区域Mg(OH)_2的分解速率也不相同,钢卷的排水过程长达28 h。保护气氛的成分和钢带层间气隙的大小对排水速率影响显著,不同工况下,钢卷平均含水量可相差20%以上。此外,钢卷下端面与底板接触紧密,排水不畅,使用镂空底板可以大幅降低钢卷层间平均含水量。
Since the atmospheric moisture content has a significant influence on the quality control of the oriented silicon steel during the high temperature annealing process,the variation law of the moisture content in the gas entrapped in the gaps between the coil layers in the annular furnace was studied. Relationship between the heating rate and the deposition rate of Mg(OH)_2 in the coating of strip was analyzed,and the uniform distribution law of the vapour in the cover during the annealing process was proved by experiments. The model of the vapour diffusion in the annular furnace was built. The results showed that the deposition rate of Mg(OH)_2 differed at different parts of the coil because of the different heating rates,and it cost about 28 h to drain the water in the coil completely. The water content of the protective atmosphere and the width of gaps between coil layers have a significant impact on the drainage rate,and the difference of the average water content is more than 20% in some specific conditions. The vapour is entrapped at the bottom of coil due to the insufficient distance between coil and the plate. Furthermore,the application of the hollowed out plate can reduce the average water content between the coil layers significantly.
引文
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