Cooling method and on-line cooling system for controlled rolling with inter-pass cooling process

Abstract

The present invention relates to controlled cooling in manufacture of steel plate, and in particular, to an on-line cooling system for controlled rolling with an inter-pass cooling process, which comprises a rolling mill and on-line cooling equipment. The cooling equipment is accessorily arranged on the exit of the rolling mill, so that the rolling mill and the cooling equipment are combined. One rolling mill and one set of on-line cooling equipment are considered a cooling group, and several such groups are connected in series, so the steel plate can be cooled in any rolling pass. In this invention, both the cooling system and the water supply system are arranged on the main frame, and the rolling process and the cooling process are synchronized by using inter-pass cooling. Consequently, satisfied rolling effect in the condition of a temperature gradient along the thickness direction, grain refinement at the surface and drastic strength improvement without sacrificing toughness are achieved. Besides, better quality of the plate center region is obtained, double bulging is avoided and the yield of steel plate is improved due to the higher deformation permeability.