Cooling device and control method for heat treatment of hot continuous rolling steel plate

Abstract

The invention discloses a cooling device for hot continuous rolling steel plate heat treatment. The cooling device comprises high pressure nozzles and low pressure water mist nozzles; the high pressure nozzles form a high pressure spray cooling system; the low pressure water mist nozzles form a low pressure water mist cooling system; the high pressure spray cooling system and the low pressure water mist cooling system are arranged sequentially so as to form the integral cooling device; and the integral cooling device carries out cooling operation on passing hot rolled steel plates at a plate passing speed of 1-75m / min. By setting a reasonable water quantity, a water ratio and a roller way speed, the steel plates are cooled to a required phase-transition temperature point in a heat treatment high pressure area, and subsequent water mist cooling provides good conditions for uniform cooling of a phase-transition process, so that structural stress can be reduced effectively, and the plate shapes after the steel plates are quenched are improved. Accurate control on the final cooling temperature can be realized by adopting the water mist cooling, and thus the cooled steel plates acquire needed phase transition structures.

Description

technical field [0001] The invention relates to a metallurgical technology, in particular to a cooling technology device and control method for off-line heat treatment of steel plates in a hot rolling production line in the field of iron and steel production. Background technique [0002] With the increasing demand for hot-rolled high-strength steel in the field of steel production in construction machinery, automobiles, containers and railways, the off-line heat treatment technology of steel plates is very important, and the cooling technology for the entire steel plate is off-line heat treatment. A core technology in process technology. [0003] The application of cooling technology in the prior art to steel plate heat treatment mainly has two aspects, one is quenching and cooling of steel plate after tempering, including soft quenching, that is, the final cooling temperature is not very high, and the other is accelerated cooling of steel plate after normalizing. [0004]...

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Problems solved by technology

[0013] In order to solve the existing water quenching cooling method in the prior art, the instantaneous cooling intensity is too large, which is easy to cause uneven cooling and plate shape problems, and due to the high water cooling intensity, the requirements of uniform cooling and precise temperature control required for flexible quenching cannot be achieved. Causes the problem of uneven performance of the steel plate after water cooling, and other cooling methods are difficult to achieve integrated cooling control with the quenching machine, a separate production line needs to be set up, the investment cost is high, the production rhythm is not compact enough, and it is not suitable for thinner The normalizing accelerated cooling of the hot continuous rolling steel plate, the cooling device is relatively simple, and the problem of precise temperature control cannot be carried out

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