Production technology for preventing 'core collapse' defect of ultrathin steel coil

Abstract

The invention discloses a production technology for preventing 'core collapse' defect of ultrathin steel coil. The production technology comprises: uncoiling a raw material steel coil by an uncoiling machine, clamping the head portion of the band steel by a clamping jaw of a recoiling machine, and coiling 1.5 circles of the band steel, then rolling the band steel for 5 to 7 times, rolling the band steel of 2.5 to 3.0 mm thick into a thin band steel whose thickness is less than 0.3 mm, and then coiling the finished steel coil by the recoiling machine, putting the finished steel coil into a warehouse after coil discharging, weighing, and bundling. A high tension start technology is used for coiling the finished coils, the core portion start tension is increased to 1.6 to 2 times of the set coiling tension stress, then the core portion start tension is gradually reduced and returned to the set tension stress of 70 N / mm2 when the outer diameter of the steel coil is 800 mm; the clamping jaw is reversed after the coiling block is shrank for 2 degrees during the coil discharging. The production technology for preventing 'core collapse' defect of ultrathin steel coil employing a hard core tension cold rolling method without increasing the number of coiling circles is able to saved the cost of manufacturing sleeves and the cost of transportation, thereby effectively removing the 'core collapse' defect of ultrathin steel coil, and increasing the production rhythm and efficiency.

Description

Technical field [0001] The invention relates to a plate and strip steel production process in the metallurgical industry, and is particularly suitable for the production process of cold rolled extremely thin steel coils. Background technique [0002] At present, many steel companies, especially small and medium-sized private steel companies, are producing cold-rolled strip steel, of which very thin chilled steel plates with a thickness of less than 0.3mm account for a large proportion. In the production of the above-mentioned thin gauge products, a reversible cold rolling mill equipped with a large-tension coiler is generally used. Due to the technological characteristics of the reversible cold rolling mill, the core of the off-line steel coil is actually wound from several turns of harder strip steel that has not been rolled to the target thickness. For extremely thin chilled steel coils with a thickness of less than 0.3mm, the usual method is to use sleeve rolling, and at the ...

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Problems solved by technology

[0003] Whether it is sleeve rolling or hard core tension coiling with increased number of coils, the production cost of cold-rolled steel enterprises will increase. The former increases sleeve manufacturing and logistics costs, and the latter resists " The effect of "collapsed core" defect is not ideal (see figure 1 ), and directly reduces the finished product rate, which may be fatal to steel companies currently in the fierce competition in the steel market

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