The investigations of quenching process for improving the flatness of the hot rolled steel plate
The improvement of quenching process on the hot rolled steel plate strongly depends on the degree of plate flatness, resulting from the distortion of the units. The heat transfer characteristics along the steel plate, which rely on the distributions of impinging water jets, are the primary factors that affect the degree of distortion. In this paper, finite element analysis (FEA) was applied to the cooling process of the steel plate manufactured in one of the steel company in Taiwan. A two-dimensional computational model was developed to simulate the distortion of the plate, including crossbows, longbows, center buckles and edge waves. The distributions of the water jet units at the bottom and top of the steel plate are studied to predict the heat transfer coefficients as well as the distortion along the surface and width of the steel plate. The internal stress including thermal and structural stresses contributed from the evolutions of internal structure is additionally investigated to fully understand the phase transformation across the steel plate during the quenching process. This study provides an optimal solution for improving the quality of the steel plate product in the hot rolled steel plate milling process.