CN-122012909-A - Method for reducing crease defect of precise strip steel brightening unit

CN122012909ACN 122012909 ACN122012909 ACN 122012909ACN-122012909-A

Abstract

The invention discloses a method for reducing crease defects of a precise strip steel brightening unit, which aims at extremely thin precise strip steel with the thickness less than or equal to 0.05mm, reduces the crease defects of the precise strip steel brightening unit through the cooperative optimization of an uncoiling degreasing section, a furnace section, an outlet loop section and a coiling section, and specifically comprises the steps of adjusting the pressure of a squeezing roller and a sealing roller to be less than 1bar, optimizing the rotating speed of a dryer fan, the position of a cooling flashboard and tension parameters of each section, adding a flattening roller and adopting a manual coiling mode. The invention solves the problem of crease defect caused by uneven stress, air flow disturbance, improper support and the like in the annealing process of the ultrathin strip steel fundamentally, obviously reduces the occurrence rate of crease defect, improves the product quality and the production efficiency, has low implementation cost and strong universality, and is suitable for upgrading and reforming the existing brightening unit.

Inventors

ZHANG GANG
DENG XIAONIAN
QI LONG
SHI XIAOCHEN

Assignees

山西太钢不锈钢精密带钢有限公司

Dates

Publication Date: 20260512
Application Date: 20260113

Claims (6)

1. The method is characterized in that the bright unit is a EBNER vertical bright annealing line, and aims at the ultra-thin precision strip steel with the thickness less than or equal to 0.05mm, and the method reduces the crease defect of the precision strip steel bright unit through the cooperative optimization of an uncoiling degreasing section, a furnace section, an outlet loop section and a coiling section, and specifically comprises the following steps: The process of the uncoiling degreasing section is optimized, namely cleaning the steel strip to remove oil stains and impurities remained on the surface of the steel strip, controlling the pressure of all squeezing rollers to be below 1bar, setting the rotating speed of a dryer fan to 600 revolutions per minute, and controlling the tension in the section to be 25N/mm 2 ; optimizing furnace section process, namely controlling the pressure of an inlet sealing roller and an outlet sealing roller to be less than 1bar, adjusting the position of a graphite roller to be 85%, adjusting the positions of No. 1, no. 3, no. 4 and No. 6 cooling flashboard of a convection cooling section to be 50%, adjusting the positions of No.2 and No. 5 cooling flashboard to be 45%, and controlling the tension in the furnace to be 4N/mm 2 ; The process of optimizing the outlet loop section comprises the steps of controlling the tension in the section to be 15N/mm 2 , respectively adding a flattening roller at the outlet of the outlet loop and in front of a No.4 tension roller, increasing the contact surface of a steel belt and a free roller, and improving the tension of the steel belt; And (3) optimizing the coiling section process, namely controlling the coiling tension to be 25N/mm 2 by adopting a manual coiling mode.
2. The method for reducing crease defects in a precision strip mill set of claim 1, wherein the cleaning process employs spraying alkali and water to clean the strip in optimizing the uncoiling degreasing section process.
3. The method for reducing crease defects in a precision strip steel brightening unit according to claim 1, wherein the water content of the strip steel surface is less than or equal to 0.5% in the process of optimizing the uncoiling degreasing section.
4. The method for reducing crease defects in a precision strip steel brightening unit according to claim 1, wherein in the process of optimizing the furnace section, the initial position of the graphite roller is 75%, the distribution of the support points after adjustment is optimized, and the suspension length of the strip steel in the cooling section is reduced.
5. The method for reducing crease defects in a precision strip light unit according to claim 1, wherein in the process of optimizing a furnace section, six cooling shutters are arranged in the convection cooling section, and the positions of the cooling shutters 1#, 3#, 4#, 6# are 40% and the positions of the cooling shutters 2#, 5# are 35% in an initial state.
6. The method for reducing crease defects in a precision strip mill set of claim 1, wherein in optimizing the reel section process, a manual reel mode is used to replace the automatic auxiliary function of the belt reel booster to eliminate the bite gap at the initial stage of reel-up.

Description

Method for reducing crease defect of precise strip steel brightening unit Technical Field The invention belongs to the technical field of heat treatment of precise strip steel, and particularly relates to a method for reducing crease defects of a precise strip steel brightening unit. Background The precise strip steel brightening unit is core equipment for realizing precise strip steel intermediate annealing and finished product annealing, and has the core functions of converting the internal structure of the rolled precise strip steel into fine equiaxial grains through a controllable atmosphere annealing process, eliminating deformation hardening generated in the rolling process, recovering the plasticity and deformation capability of the strip steel, ensuring the surface of the strip steel to keep a brightening state, and meeting the requirements of subsequent precise processing on the surface quality. In the actual production process, aiming at the extremely thin precision strip steel with the thickness less than or equal to 0.05mm, the strip drawing phenomenon is easy to occur in the annealing process of the brightening unit due to the low self rigidity, weak deformation resistance and other problems of uneven acting force of equipment, poor matching of technological parameters and the like, so that crease defects are formed. The defect can lead the strip steel to be reworked, thereby not only reducing the production efficiency and increasing the production cost, but also affecting the stability of the production rhythm, and simultaneously, the requirements of the ultra-thin precision strip steel on the equipment operation precision and the process parameter control precision are far higher than those of the conventional strip steel, and the production difficulty is further increased. In the prior art, the optimization of a precise strip steel brightening unit focuses on the performance improvement of the strip steel with the conventional specification, and a systematic solution for the crease defect of the strip steel with the extremely thin specification is lacking. For example, in the prior art, it is common to increase the wringing roller pressure, increase the dryer fan speed to ensure the dewatering effect, or increase the sealing roller pressure to ensure the purity of the furnace atmosphere, but these conventional operations for extremely thin strip steel can rather exacerbate stress unevenness and jitter, resulting in frequent crease defects. Disclosure of Invention In order to at least partially solve the technical problems existing in the prior art, the invention provides a method for reducing the crease defect of a precise strip steel brightening unit, wherein the brightening unit is a EBNER vertical brightening annealing line, the method aims at reducing the crease defect of the precise strip steel brightening unit by the cooperative optimization of an uncoiling degreasing section, a furnace section, an outlet loop section and a coiling section aiming at the extremely thin precise strip steel with the thickness less than or equal to 0.05mm, and the method specifically comprises the following steps: The process of the uncoiling degreasing section is optimized, namely cleaning the steel strip to remove oil stains and impurities remained on the surface of the steel strip, controlling the pressure of all squeezing rollers to be below 1bar, setting the rotating speed of a dryer fan to 600 revolutions per minute, and controlling the tension in the section to be 25N/mm 2; optimizing furnace section process, namely controlling the pressure of an inlet sealing roller and an outlet sealing roller to be less than 1bar, adjusting the position of a graphite roller to be 85%, adjusting the positions of No. 1, no. 3, no. 4 and No. 6 cooling flashboard of a convection cooling section to be 50%, adjusting the positions of No.2 and No. 5 cooling flashboard to be 45%, and controlling the tension in the furnace to be 4N/mm 2; The process of optimizing the outlet loop section comprises the steps of controlling the tension in the section to be 15N/mm 2, respectively adding a flattening roller at the outlet of the outlet loop and in front of a No.4 tension roller, increasing the contact surface of a steel belt and a free roller, and improving the tension of the steel belt; And (3) optimizing the coiling section process, namely controlling the coiling tension to be 25N/mm 2 by adopting a manual coiling mode. Furthermore, in the method for reducing the crease defect of the precise strip steel brightening unit, in the process of optimizing the uncoiling degreasing section, the cleaning treatment adopts the injection of alkali liquor and water to clean the strip steel. Further, in the method for reducing the crease defect of the precise strip steel brightening unit, the water content of the strip steel surface is less than or equal to 0.5% in the process of optimizing the uncoiling degreasing section. In the method f