阅读说明：本技术 一种服饰用超薄冷轧钢带的生产方法 (Production method of ultrathin cold-rolled steel strip for clothing ) 是由 唐时葵 于 2021-07-23 设计创作，主要内容包括：本发明公开了一种服饰用超薄冷轧钢带的生产方法,包括以下步骤,挑选原料、软化退火、轧制、重卷、去应力退火、拉矫、分条、检验包装入库；本发明进行了一系列的创新设计,从原料选择上,以轧硬卷替代热轧钢带,减少了热轧酸洗及粗轧等工序,工艺流程大幅缩短；从轧制工艺上进行了创新,缩减了一个轧程,提高生产效率的同时,降低了轧制成本；从热处理工艺上进行了创新,增加了升温平台,提高了性能均匀性；采用双弯双矫拉伸矫直工艺替代平整工艺,提高了带型及屈服平台的消除能力。(The invention discloses a production method of an ultrathin cold-rolled steel strip for clothing, which comprises the following steps of selecting raw materials, softening annealing, rolling, rewinding, stress relief annealing, straightening and withdrawal, splitting, inspecting, packaging and warehousing; according to the invention, a series of innovative designs are carried out, and from the selection of raw materials, the hard-rolled coil is used for replacing a hot-rolled steel strip, so that the working procedures of hot-rolling pickling, rough rolling and the like are reduced, and the process flow is greatly shortened; innovations are made on the rolling process, one rolling process is reduced, the production efficiency is improved, and the rolling cost is reduced; innovations are made on the heat treatment process, a heating platform is added, and the performance uniformity is improved; the double-bending double-straightening stretching and straightening process is adopted to replace a flattening process, so that the elimination capability of the belt shape and the yield platform is improved.)

1. A production method of an ultrathin cold-rolled steel strip for clothes is characterized by comprising the following steps,

step one, selecting raw materials: selecting a steel belt with the specification of 0.7mm × 575-615 mm;

step two, softening and annealing: the softening annealing adopts a natural gas bright cover furnace, and specifically comprises the following steps;

charging: stacking the steel strips obtained in the first step on a furnace platform in a shape of Chinese character 'pin', and fastening an inner container;

and (3) heating: covering a heating cover, and heating to 670 ℃ at the heating rate of 80 ℃/h;

and (3) heat preservation: keeping the temperature at 670 ℃ for 17 hours;

air cooling: hanging away the heating cover, cooling to 580 ℃ along with the furnace, buckling the cooling cover, performing air cooling for 4 hours, when the temperature in the furnace is reduced to 320 ℃, hanging away the cooling cover, and cooling along with the furnace;

air cooling: when the temperature of the steel strip is reduced to 100 ℃, the inner container is lifted away for air cooling;

discharging: and taking out the furnace when the air is cooled to room temperature.

Step three, rolling: and (3) conveying the steel strip in the step two to an HC rolling mill for 4 passes of rolling, wherein the rolling reduction is 0.7mm, 0.50mm, 0.35mm, 0.25mm and 0.20mm in sequence, all flat rolls are adopted in the rolling process, and the plate shape is adjusted by drawing intermediate rolls.

Step four, rewinding: and D, conveying the steel strip obtained in the step three to a recoiling unit for decoiling.

Step five, stress relief annealing, wherein an electric heating hood type bright annealing furnace is adopted, and the method specifically comprises the following steps,

charging: stacking the single coil of the steel strip obtained in the step four on a furnace platform, fastening an inner container, and introducing high-hydrogen protective gas;

and (3) heating: covering a heating cover, heating to 480 ℃ at the heating rate of 120 ℃/h, and keeping the temperature for 2 h; then continuing heating up, and heating up to 650 ℃ according to the heating rate of 80 ℃/h;

and (3) heat preservation: keeping the temperature at 650 ℃ for 16 hours;

air cooling: hanging away the heating cover, cooling to 500 ℃ along with the furnace, covering the cooling cover for air cooling for 4h,

when the temperature in the furnace is reduced to 280 ℃, the cooling cover is lifted away and cooled along with the furnace;

air cooling: when the temperature of the steel coil is reduced to 80 ℃, the inner container is lifted away for air cooling;

discharging: and taking out the furnace when the air is cooled to room temperature.

Step six, withdrawal and straightening: and D, adopting double bending and double straightening, and conveying the steel belt obtained in the step five to a straightening and withdrawing unit for stretching and straightening.

Step seven, splitting: and conveying the steel belt obtained in the step six to a slitting machine set, and cutting edges or slitting into narrow strips.

Step eight, inspecting, packaging and warehousing: and (5) inspecting the steel strip obtained in the step seven, and packaging and warehousing after the steel strip is qualified.

2. The method for producing the ultrathin cold-rolled steel strip for clothes as claimed in claim 1, wherein after the inner container is fastened in the second step, high-hydrogen protective gas is introduced.

Technical Field

The invention relates to the technical field of cold-rolled steel strips, in particular to a production method of an ultrathin cold-rolled steel strip for clothes.

Background

The production process of the existing cold-rolled steel strip for clothes comprises the following steps:

the process route comprises the steps of raw materials (hot rolled steel strips with the thickness of 2.5-2.75 mm) → pickling → primary rolling (four-stand continuous rolling) → intermediate annealing → secondary rolling (four-stand continuous rolling) → split rolling → loose rolling → stress relief annealing → flattening → inspection and packaging and warehousing.

The rolling process is divided into two rolling processes, wherein the first rolling process is 2.5mm → 2.0mm → 1.5mm → 1.1mm → 0.9 mm; the second rolling pass is 0.9mm → 0.6mm → 0.45mm → 0.25mm → 0.2 mm.

The annealing process comprises two times of annealing, wherein the intermediate annealing process comprises charging, heating to 680 ℃ (the heating rate is 85 ℃/h, the heating time is 8h), keeping warm for 680 ℃ (the keeping warm time is 18h), air cooling to 350 ℃ (the air cooling time is 5h), cooling to 100 ℃ along with the furnace (the cooling time along with the furnace is 16h), and discharging; the stress relief annealing comprises the steps of charging → heating to 650 ℃ (heating rate 85 ℃/h, heating time 8h) → heat preservation 680 ℃ (heat preservation time 18h) → air cooling to 320 ℃ (air cooling time 5h) → furnace cooling to 100 ℃ (furnace cooling time 16h) → discharging

Disadvantages of the prior art

(1) The process route is long, and the production efficiency is low: 2 rolling passes and 8 passes are needed from the raw materials to the finished product, the number of the passes is large, and the processing cost is high.

(2) The steel strip quality is unstable, the waste flushing rate of products is high: when the product is applied to deep drawing, due to the anisotropy of the steel strip, the punched piece has skirt lace defects, thereby increasing the punching waste rate.

(3) There is a certain environmental impact: the hot rolled coil needs to be washed with acid to remove oxide skin, and the waste water can affect the environment.

Disclosure of Invention

The invention aims to provide a production method of an ultrathin cold-rolled steel strip for clothes, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a production method of an ultrathin cold-rolled steel strip for clothes comprises the following steps,

step one, selecting raw materials: selecting a steel belt with the specification of 0.7mm × 575-615 mm;

step two, softening and annealing: the softening annealing adopts a natural gas bright cover furnace, and specifically comprises the following steps;

charging: stacking the steel strips obtained in the first step on a furnace platform in a shape of Chinese character 'pin', and fastening an inner container;

and (3) heating: covering a heating cover, and heating to 670 ℃ at the heating rate of 80 ℃/h;

and (3) heat preservation: keeping the temperature at 670 ℃ for 17 hours;

air cooling: hanging away the heating cover, cooling to 580 ℃ along with the furnace, buckling the cooling cover, performing air cooling for 4 hours, when the temperature in the furnace is reduced to 320 ℃, hanging away the cooling cover, and cooling along with the furnace;

air cooling: when the temperature of the steel strip is reduced to 100 ℃, the inner container is lifted away for air cooling;

discharging: and taking out the furnace when the air is cooled to room temperature.

Step three, rolling: and (3) conveying the steel strip in the step two to an HC rolling mill for 4 passes of rolling, wherein the rolling reduction is 0.7mm, 0.50mm, 0.35mm, 0.25mm and 0.20mm in sequence, all flat rolls are adopted in the rolling process, and the plate shape is adjusted by drawing intermediate rolls.

Step four, rewinding: and D, conveying the steel strip obtained in the step three to a recoiling unit for decoiling.

Step five, stress relief annealing, wherein an electric heating hood type bright annealing furnace is adopted, and the method specifically comprises the following steps,

charging: stacking the single coil of the steel strip obtained in the step four on a furnace platform, fastening an inner container, and introducing high-hydrogen protective gas; and (3) heating: covering a heating cover, heating to 480 ℃ at the heating rate of 120 ℃/h, and keeping the temperature for 2 h; then continuing heating up, and heating up to 650 ℃ according to the heating rate of 80 ℃/h;

and (3) heat preservation: keeping the temperature at 650 ℃ for 16 hours;

air cooling: hanging away the heating cover, cooling to 500 ℃ along with the furnace, buckling the cooling cover for air cooling, wherein the air cooling time is 4h, hanging away the cooling cover when the temperature in the furnace is reduced to 280 ℃, and cooling along with the furnace;

air cooling: when the temperature of the steel coil is reduced to 80 ℃, the inner container is lifted away for air cooling;

discharging: and taking out the furnace when the air is cooled to room temperature.

Step six, withdrawal and straightening: and D, adopting double bending and double straightening, and conveying the steel belt obtained in the step five to a straightening and withdrawing unit for stretching and straightening.

Step seven, splitting: and conveying the steel belt obtained in the step six to a slitting machine set, and cutting edges or slitting into narrow strips.

Step eight, inspecting, packaging and warehousing: and (5) inspecting the steel strip obtained in the step seven, and packaging and warehousing after the steel strip is qualified.

Furthermore, after the inner container is buckled in the second step, high-hydrogen protective gas is introduced, and due to the fact that hydrogen is used as heat transfer medium protective gas and the characteristic that the heat conduction efficiency of hydrogen is high, the steel strip can be effectively and uniformly heated, in addition, the hydrogen not only has an anti-oxidation effect on the steel strip, but also has a reduction effect on rust on the steel strip, and therefore bright annealing of the steel strip is achieved.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, a series of innovative designs are carried out, and from the selection of raw materials, the hard-rolled coil is used for replacing a hot-rolled steel strip, so that the working procedures of hot-rolling pickling, rough rolling and the like are reduced, and the process flow is greatly shortened; innovations are made on the rolling process, one rolling process is reduced, the production efficiency is improved, and the rolling cost is reduced; innovations are made on the heat treatment process, a heating platform is added, and the performance uniformity is improved; the double-bending double-straightening stretching and straightening process is adopted to replace a flattening process, so that the elimination capability of the belt shape and the yield platform is improved.

(1) In the aspect of raw material selection, the hard-rolled coil replaces a hot-rolled steel strip, the original procedures of hot-rolled pickling, rough rolling and the like are reduced, the process flow is greatly shortened, and meanwhile, the environmental influence caused by pickling is reduced.

(2) In the aspect of rolling process, the two rolling passes are reduced to one rolling pass, namely 4 rolling passes are reduced, so that the production efficiency is improved, and meanwhile, the rolling cost is reduced.

(3) In the aspect of the annealing process, a heat preservation platform is added in the temperature rise stage, and the uniformity of the furnace temperature in the annealing process is improved through the control of the temperature rise rate, namely the uniformity of the performance of the steel strip is improved, the heat preservation time is shortened, the annealing period is shortened on the whole, and the energy is saved.

(4) The double-bending double-correction stretch bending correction technology replaces a flattening process, quality defects such as wave edges, wave shapes, buckling, sickle bends and the like are eliminated, a good plate shape is obtained, meanwhile, the anisotropy of the steel strip is reduced, and the deep punching performance of the product is improved.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The following examples will explain the present invention in detail, however, the present invention is not limited thereto. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the embodiment of the invention: provides a production method of an ultrathin cold-rolled steel strip for clothes, which comprises the following steps,

step one, raw material selection: selecting a hard rolling coil with the specification of 0.7mm × 575-615 mm;

step two, softening and annealing adopt a natural gas bright cover furnace, and charging: stacking the steel strips obtained in the first step on a furnace platform in a shape of Chinese character 'pin', and fastening an inner container; and (3) heating: covering a heating cover, and heating to 680 ℃ at the heating rate of 85 ℃/h; and (3) heat preservation: keeping the temperature at 680 ℃ for 18 hours; air cooling: hanging away the heating cover, cooling to 580 ℃ along with the furnace, buckling the cooling cover for air cooling, wherein the air cooling time is 4h, hanging away the cooling cover when the temperature in the furnace is reduced to 320 ℃, and cooling along with the furnace; air cooling: when the temperature of the coil is reduced to 100 ℃, the inner container is lifted away for air cooling; discharging: and taking out the furnace when the air is cooled to room temperature.

Step three, rolling: and (3) conveying the steel strip obtained in the second step to an HC rolling mill for 4 passes of rolling, wherein the rolling reduction is distributed to be 0.7mm → 0.50mm → 0.35mm → 0.25mm → 0.20mm, all flat rolls are adopted in the rolling process, and the plate shape is adjusted by drawing of intermediate rolls.

Step four, rewinding: and (5) conveying the steel strip obtained in the step three to a recoiling unit for uncoiling so as to remove the coil tension generated in the rolling process.

Step five, stress relief annealing: an electric heating hood type bright annealing furnace is adopted. Charging: stacking the single coil of the steel strip obtained in the step four on a furnace platform, fastening an inner container, and introducing high-hydrogen protective gas; and (3) heating: covering a heating cover, heating to 480 ℃ at a heating rate of 120 ℃/h, and keeping the temperature for 2h to form a heating platform so as to improve the temperature uniformity in the furnace; then continuing heating up, and heating up to 650 ℃ at the heating rate of 85 ℃/h; and (3) heat preservation: keeping the temperature at 650 ℃ for 16 hours; air cooling: hanging away the heating cover, cooling to 500 ℃ along with the furnace, buckling the cooling cover for air cooling, wherein the air cooling time is 4h, hanging away the cooling cover when the temperature in the furnace is reduced to 280 ℃, and cooling along with the furnace; air cooling: when the temperature of the coil is reduced to 80 ℃, the inner container is lifted away for air cooling; discharging: and taking out the furnace when the air is cooled to room temperature.

Step six, withdrawal and straightening: and D, adopting double bending and double straightening, and conveying the steel belt obtained in the step five to a straightening and withdrawing unit for stretching and straightening.

Step seven, splitting: and conveying the steel belt obtained in the step six to a slitting machine set, and cutting edges or slitting into narrow strips.

Step eight, inspecting, packaging and warehousing: and (5) inspecting the steel strip obtained in the step seven, and packaging and warehousing after the steel strip is qualified.

According to the above embodiment, further, after the inner container is fastened in the second step, a high hydrogen protective gas is introduced.

It needs to be supplemented that most products produced by other processes are not straightened and have self stress, after coiling, the products are elastically deformed, after coiling and releasing, the steel strip can recover due to the self stress, and the cold-rolled steel strip produced by the production method has the advantages that the yield strength is reduced through straightening and pulling, the plastic deformation is realized, the plastic deformation can not cause the deformation of the products due to the disappearance of external force, and the punching rate is reduced to about three thousandths from about ten thousandths of the prior art.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.