Annealing and bluing process of common cold-rolled coil

Abstract

The invention discloses an annealing and bluing process of a common cold-rolled coil. The annealing and bluing process comprises the following steps that (1) the common cold-rolled coil heated to be at the process temperature of 650-710 DEG C is subjected to heat preservation for 6-9 hours under the protection of nitrogen for annealing; (2) a common cold-rolled coil strip cover is cooled to 400 DEG C along with air cooling of a furnace under the protection of nitrogen; (3) air cooling is stopped, the common cold-rolled coil is naturally and slowly cooled to 360 DEG C in the cover, the time is60-120 Min, and the effect of homogenizing the temperature of the whole cold-rolled coil is achieved; (4) the common cold-rolled coil is discharged from the furnace at the high temperature of 360 DEGC and placed on a final cooling table, a cooling fan is kept to carry out 8000 Pa forced air cooling till the temperature of the steel coil is reduced to 160 DEG C, and the oxidation bluing treatmenttemperature of the steel coil is 160-360 DEG C; and (5) forced air cooling, and is stopped and the steel coil is naturally cooled to be at a room temperature. By adopting the method to treat the common cold-rolled coil, good annealing quality can be ensured, and meanwhile a uniform bluing effect can be obtained.

Description

technical field [0001] The invention relates to an annealing and bluing process of common cold-rolled coils. Background technique [0002] The current production process of ordinary cold-rolled coils is that the cold coils are bright annealed in a full-hydrogen bell-type furnace first, and then oiled on the surface and delivered to the user. The product achieves the goal of smooth surface and no rust. Since the cold-rolled coil is bright annealed in a full-hydrogen bell furnace, the surface of the steel coil is pure iron and is easily oxidized in a pure reducing atmosphere. Therefore, the current process is to coat a layer of anti-rust oil on the surface after annealing to prevent the steel coil from rusting; and for For users, the anti-rust oil on the surface must be cleaned after the final processing of cold-rolled coils, so the discharge of cleaning sewage has become a pain point for downstream users. There are two main ways to protect the surface of steel coils, one is ...

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Problems solved by technology

The disadvantage of this process is that the process is complicated, and it also