Achievement of ultrafast cooling rate in a hot steel plate by air-atomized spray with different surfactant additives
Achievement of ultrafast cooling rate in a hot steel plate by air-atomized spray with different surfactant additives
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DOI：
10.1016/j.expthermflusci.2013.05.007
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发表时间：
2013-10
影响因子：
3.2
通讯作者：
S. Ravikumar;J. M. Jha;Ishita Sarkar;S. Mohapatra;Surjya K. Pal;S. Chakraborty
中科院分区：
文献类型：
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作者：
S. Ravikumar;J. M. Jha;Ishita Sarkar;S. Mohapatra;Surjya K. Pal;S. Chakraborty
通过高流量空气和水的条件实现了6 mm厚热不锈钢板（AISI 304）的超快冷却，这是热轧带钢轧机的输出台所需的，以开发先进的高强度钢。本研究主要研究在空气雾化水喷雾中添加不同类型、不同浓度水平的表面活性剂对提高超快冷却速率的影响。所用的阴离子、阳离子和非离子表面活性剂通过测量它们的表面张力、接触角和粘度来表征。表面活性剂强化传热实验已经进行了与全锥雾化器在一个固定的喷嘴表面的距离，使用恒定的空气和水的流速优化较早。在每种情况下，测试板的初始表面温度保持在900 °C。实验测量已被应用到商业逆热传导求解器（INTEMP）估计局部表面热通量以及表面温度的历史。所有表面活性剂的浓度已经基于最高冷却速率进行了优化。根据它们的铺展性、润湿特性和泡沫形成能力，发现阳离子和非离子表面活性剂比阴离子表面活性剂产生更好的冷却效果。这些增强的超快冷却速率可用于在钢铁工业中生产先进的高强度钢。
Ultrafast cooling of a 6 mm thick hot stainless steel plate (AISI 304) has been achieved by high flow conditions of air and water, which is needed at the runout table of a hot strip mill to develop advanced high strength steels. The present study primarily focuses on the effect of adding different types of surfactants at various concentration levels to air atomized water spray for enhancement of ultrafast cooling rate. The anionic, cationic and non-ionic surfactants used have been characterized by measuring their surface tension, contact angle and viscosity. The surfactant enhanced heat transfer experiments have been conducted with a full cone atomizer at a fixed nozzle to surface distance using constant air and water flow rates optimized earlier. The initial surface temperature of the test plate has been maintained at 900 °C in each case. The experimental measurements have been applied to a commercial inverse heat conduction solver (INTEMP) to estimate local surface heat flux as well as surface temperature histories. The concentration of all the surfactants has been optimized based on the highest cooling rate. Depending on their spreadability, wetting characteristics and ability to foam formation, the cationic and non-ionic surfactants are found to produce better cooling effects than the anionic surfactant. These enhanced ultrafast cooling rates can be useful to produce advanced high strength steels in the steel industries.