Heat treatment method of ahss hot-rolled coil, cold rolling method and heat treatment device using the same

Abstract

A heat treatment method for AHSS hot-rolled coils is disclosed. The heat treatment method of the AHSS hot-rolled coil according to the embodiment of the present invention includes: a hot-rolled coil generation step, hot-rolling and cooling the rolled material, and then coiling to prepare the hot-rolled coil; the first cooling step , cooled to the temperature at which the phase transformation is completed, so as to generate a hard phase at the edge of the hot-rolled coil; in the step of weakening the edge of the hot-rolled coil, only the edge of the hot-rolled coil is heated and heated to the tempering temperature, The heat treatment is then maintained at the tempering temperature for a predetermined time so that the edge portion of the hot-rolled coil subjected to the first cooling step has a strength similar to that of the central portion of the hot-rolled coil; the second cooling step, The hot-rolled coil subjected to the step of weakening the edge strength of the hot-rolled coil is cooled.

Description

technical field [0001] The present invention relates to a heat treatment method for a hot-rolled coil and a heat treatment device for performing heat treatment by heating a wound coil. Background technique [0002] The hot rolling process implemented in the iron and steel preparation process is to reheat the slab prepared in the blast furnace to a temperature suitable for rolling in a heating furnace, and then pass it through a rough rolling mill (Roughing Mill) and a finishing mill (Finishing Mill). The series of rolling devices are used to roll hot-rolled steel plates in the form of strips, and after being cooled by cooling equipment, they are wound into coils by winders. Furthermore, the wound hot-rolled coils are stacked in a yard and air-cooled, and then transported to a cold-rolling factory or shipped as a product. [0003] In the air cooling process, the edge of the hot-rolled coil in contact with the atmosphere and the inside of the hot-rolled coil have material dev...

AI Technical Summary

Problems solved by technology

[0009] However, in this type of coil heating equipment, most of the hot air flows outside the sides and outer peripheral surfaces of the coil, so that the hot air flowing into the hollow portion of the coil is relatively scarce.

Additionally, the lower face of the coil is shielded by the coil saddle so hot air cannot reach it

Therefore, it is difficult to heat the coil uniformly as a whole, and there is a limitation in obtaining a uniform heat treatment effect as a whole

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