Duplex Cold Rolling Line

Abstract

A composite cold rolling line includes a feed unit, a first rolling unit at downstream of the feeding unit, an annealing and descaling unit at downstream of the first rolling unit, and a pickling unitat downstream of the annealing and descaling unit, a second rolling unit at downstream of the pickling unit, and a back-feed unit at downstream of the second rolling unit. The first cold rolling millcan perform preliminary rolling before the annealing and pickling process. The product can reduce the thickness of the rolling required for the second rolling, produce a large amount of Cold-rolled thin hard-coated steel coils with continuous high productivity. Due to the initial rolling, the black-skin coils can reduce 30 to 70% of the amount of rust, reduce the number and length of rust removalequipment. In addition to equipment cost reduction, sand blast, usage of acid liquid and discharge of acid are reduced, and the environmental protection effects of energy saving and waste reduction are realized.

Description

technical field [0001] The present invention relates to a composite cold rolling line, in particular to a composite cold rolling system for continuously and massively producing cold-rolled thin and hard steel coils with a minimum thickness of 0.25 mm from the input black steel coils. Wire. Background technique [0002] refer to figure 1 , the traditional cold-rolling process of stainless steel is to use the black steel coil F1 as the material, and use the hot-rolled annealing and pickling line A to make NO.1 steel coil F2 after annealing, sandblasting and pickling processes, and then NO. 1. Steel coil F2 is reciprocated and multi-pass rolled by the 20-roller cold rolling mill of cold rolling line B until the NO.1 steel coil F2 is rolled to the target thickness, which is cold-rolled thin and hard plate steel coil F3 . Cold-rolled thin and hard plate coil F3 can produce 2D steel coil F4, 2B steel coil F5, F6 after other processes such as cold-rolled annealing and pickling l...

AI Technical Summary

Problems solved by technology

[0003] The aforementioned cold rolling process is sent to the hot-rolled annealing and pickling line A in the black steel coil F1. After the annealing process, the oxide scale on the surface will be thickened, and the subsequent mechanical rust removal process such as sandblasting and pickling must be strengthened. Wait for the chemical rust removal process to remove the scale on the surface of the steel coil, so it is necessary to increase the sandblasting machine and increase the sandblasting speed, increase the length of the pickling tank and increase the acid concentration, resulting in equipment costs, sandblasting and acid consumption and subsequent increase in waste disposal costs

And because there is no significant difference in thickness between the incoming black skin coil F1 and the outgoing NO. help

[0004] The NO.1 steel coil F2 enters the subsequent cold rolling line B process, which uses a single-seat 20-roller cold rolling mill for reciprocating rolling, and the number of rolling passes required will result in a higher output per unit time. However, this kind of reciprocating cold rolling mill cannot provide a large amount of cold rolling due to the large reduction rate required for the production of thin steel plates, the high probability of strip breakage, the large number of rolling passes, and the long rolling time required. Thin hard plate steel coil F3

In addition, this kind of reciprocating rolling mill needs to establish tension by coiling. Therefore, the head and tail sections of the steel coil will each have a length of about 6-8m for coiling, and the off-gauge that has not been rolled must be cut off, and the material loss of the cut section will cause Even if this problem is welded before the coil preparation line of the previous process, there will still be a 3m long off-gauge, and the on-line cost of the derived coil preparation line and the cost of the guide tape will increase.

[0005] In addition, because the traditional cold-rolled annealing and pickling line C and the cold rolling mill are independent production lines, the black skin incoming steel coil F1 is uncoiled, rolled, hot-rolled, annealed, and pickled, and the coiling is NO .1 Steel coil F2, while NO.1 steel coil F2 needs to be uncoiled on-line in cold rolling production and rolled after completion of rolling delay to obtain cold-rolled thin and hard plate steel coil F3, so much waste of hot-rolled annealing line collection Coil and cold rolling mill on-line uncoiling time, resulting in reduced production efficiency

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