Method of controlling cooling of hot-rolled steel sheet and system therefor
AssigneeKawasaki Steel Corporation
InventorsMasahiko Morita, Osamu Hashimoto
Life of this patent
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Abstract
In controlling the cooling of a hot-rolled steel sheet after hot rolling, a target value of a transformation rate required for obtaining mechanical properties ultimately expected from the hot-rolled steel plate is previously determined, a rate of gamma to alpha transformed fraction of the hot-rolled steel sheet in a section in which the cooling is controlled is detected by transformed fraction detectors, and an elapsed time from the start of cooling is measured to determine the transformation rate of the steel sheet in a cooling stage, the conditions of cooling being controlled so that the transformation rate can coincide with the target value.
Claims10
A method of controlling the cooling of a hot-rolled steel sheet after hot rolling, comprising:
- determining a target value of a transformation rate required for obtaining mechanical properties ultimately expected from said hot-rolled steel sheet;
- determining the fraction of gamma to alpha transformation of said hot-rolled steel sheet, in a section in which the cooling is controlled, by at least one transformed fraction detector;
- measuring an elapsed time from the start of cooling;
- calculating the transformation rate of said steel sheet in the cooling stage from the gamma to alpha transformed fraction and the elapsed time;
- and
- controlling the conditions of cooling so that the transformation rate in the cooling stage coincides with said target value.
A system for controlling the cooling of a hot-rolled steel sheet after hot rolling, comprising:
- means for setting a target value of a transformation rate required for obtaining predetermined mechanical properties ultimately expected from said hot-rolled steel sheet;
- at least one transformed fraction detector for determining the fraction of gamma to alpha transformation of said hot-rolled steel sheet in a section in which the cooling is controlled;
- means for measuring an elapsed time from the start of cooling;
- means for calculating the transformation rate of said steel sheet in the cooling stage from the rate of gamma to alpha transformed fraction and said elapsed time;
- and
- means for controlling the cooling conditions so that the transformation rate in the cooling stage coincides with said target value.
Dependencies are inferred from the claim text.