ABSTRACT

The microstructure and mechanical properties of the hot rolled steel depend on the laminar jet cooling control on the runout table. An experimental and numerical study of the heat transfer during water jet impingement cooling of a hot steel plate (600 to 900°C) is presented. The effects of plate temperature upon the heat transfer were analyzed by the inverse heat conduction method that provided the heat fluxes on top surface from measured temperatures into the plate. Rewetting (liquid-solid contact) occurs on surface above 880°C. Higher initial temperatures enlarge the heat flux, but delay the onset of the rewetting and the advance of rewetting front radius (R_wet). Heat transfer coefficient (HTC) increases as surface temperature decreases. The size of the non-symmetric effective jet cooling zone depends on strip speed. Correlations to predict HTC and Rwet have been proposed. Results will contribute for enhancement of fast cooling system in hot strip mill.

摘要

热轧钢的显微组织和机械性能取决于跳动台上的层流喷射冷却控制。介绍了对热钢板（600 至 900°C）进行水射流冲击冷却过程中传热的实验和数值研究。板温度对传热的影响通过逆热传导方法进行分析，该方法提供了从测量温度到板的顶面热通量。再润湿（液固接触）发生在 880°C 以上的表面。较高的初始温度会增大热通量，但会延迟再润湿的开始和再润湿锋半径（R_湿）。传热系数 (HTC) 随着表面温度的降低而增加。非对称有效射流冷却区的大小取决于带钢速度。已经提出了预测 HTC 和 Rwet 的相关性。结果将有助于提高热轧机快速冷却系统。