Annealing treating process for cold rolled steel coil

Abstract

The present invention relates to heat treatment of metallurgical product, and is especially one annealing treatment process for cold rolled steel coil in the cover furnace. Technologically, the present invention features the high maintaining temperature difference and temperature lowering and maintaining control. That is, the annealing treatment process has raised annealing temperature below the phase change line, increased temperature difference between inside and outside the steel roll, prolonged time with steel roll outer temperature lower than the steel roll core temperature, lowering the steel roll core temperature in the later temperature maintaining stage to lower the pressure stress inside the steel roll to avoid sticking fault. The present invention has raised annealing quality and output.

Description

technical field [0001] The invention belongs to the heat treatment process of metallurgical products, in particular to the annealing process of cold-rolled steel coil bell furnace. Background technique [0002] In the production process of cold-rolled sheets in metallurgical enterprises, post-rolling annealing is an indispensable production process, and the bonding after annealing is one of the main defects that affect the yield of products. According to the production statistics of a certain factory, the bonding rate generally accounts for 0.4%-2% of the total product. Calculated on the basis of an annual output of 1 million tons of steel, the average annual waste due to bonding is as high as 4,000 tons-20,000 tons. [0003] At present, the traditional treatment process of lowering the heat preservation temperature and cooling with a hood is usually used in domestic cold rolling mills. For example, deep drawing steel is annealed at 700°C, the holding time is as long as 30-...

AI Technical Summary

Problems solved by technology

Therefore, it will have a negative impact on steel with a recrystallization temperature greater than 660 ° C, and more seriously, reduce the production capacity of heat treatment, resulting in an imbalance in the production table cover ratio, which will directly affect the quality of the product and the output of the steel plant

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