Manufacturing method of hot-rolled steel sheet

摘要

The present invention provide a manufacturing method of a hot-rolled steel sheet capable of providing a target temperature for temperature of a rolled material in a final stand in a row of hot finishing mills, even when disposing a cooling device capable of cooling from inside the row of hot finishing mills. The method comprises: rapidly cooling the rolled material by spraying cooling water at inside of the final stand on a lower process side of the final stand in the row of hot finishing mills; obtaining an entry-side surface temperature of the rolled material on an entry side of the final stand; and calculating a target surface temperature on the entry side of the final stand, from a target surface temperature on the exit side of the final stand, based on generated heat and temperature reductions by contact of work rolls with the rolled material and by air cooling.

主权项

1. A manufacturing method of a hot-rolled steel sheet, wherein cooling water is sprayed at an inside of a housing of a final stand on a lower process side of the final stand, which is disposed on an end on the lower process side in a row of hot finishing mills, to rapidly cool a rolled material;
a surface temperature of the rolled material is measured on an entry side of the final stand, to obtain an entry-side surface temperature; and an entry-side target surface temperature, which is a target surface temperature of the rolled material at the measurement position of the entry-side surface temperature, is calculated from an exit-side target surface temperature, which is a target surface temperature of the rolled material on an exit side of the final stand, based on: a temperature increase by a heat generated by rolling processing in the final stand; a temperature reduction by contact of a work roll in the final stand with the rolled material; and a temperature reduction by air cooling in transportation from the measurement position of the entry-side surface temperature to the work roll of the final stand.