The thermal expansion of HSS material is large, and the uneven roll temperature distribution is easy to produce uneven thermal expansion and abnormal oxide film fall off, which affect the thermal crown and roll gap precision.The key factor affecting the oxidation film and thermal crown of high speed steel roll is the roll surface temperature.
Therefore, the good cooling system will shorten the cooling time of roll surface from the high temperature which are important to control the oxide film thickness of the roll surface, reduce the thermal crack. During the hot rolling process, the instantaneous contact temperature of the roll is 600℃~750℃, and the temperature of the roll body exceeds 50℃. After the roll surface comes out of the contact arc, the temperature must be reduced from 700℃ to below 300℃ as soon as possible to prevent further oxidation.After the roller passes through the instantaneous high temperature contact zone, the rapid operation in the 100% water-cooled environment is conducive to the formation of Fe3O4 oxide film with the best protection performance.The cooling effect of the roll can be enhanced by increasing the cooling water at the outlet side, reducing the cooling water at the inlet side and reducing the height of the water cutting plate.
By optimizing the distribution of roll cooling water and increasing the cooling water in the middle of the roll, the temperature of the roll surface can be significantly reduced and the temperature distribution uniformity can be improved
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