CN-122007175-A - Feedforward control method for off-tracking of strip steel in furnace of Sendzimir method hot galvanizing unit

Abstract

The invention relates to the technical field of cold rolling, in particular to a feedforward control method for off-tracking of strip steel in a furnace of a Sendzimir method hot galvanizing unit. Setting a plate shape I value and a wave height allowable value based on the grade and the width of the steel, setting a furnace region tension coefficient and an actual tension based on the grade and the thickness of the steel, setting a furnace roller convexity value based on the grade and the thickness of the steel, and presetting the parameters in a control system and executing the parameters before the strip steel enters the furnace. According to the invention, a plate-shape-tension-roller convex cooperative parameter pedigree covering CQ, DQ, DDQ full-scale and 0.3-2.5 mm full-thickness is established for the first time, so that active defense of deviation source reduction, stable matching of the sticking rollers and automatic deviation correction grading construction is realized. The invention realizes zero deflection of the band steel in the furnace without newly increasing equipment investment, eliminates hidden danger of band breakage, obviously improves quality, efficiency and intrinsic safety, and has extremely high industrial popularization value.

Inventors

• WANG PENG
• LIU XIAOHUI
• WANG ZHIMIN
• ZHU WEIYAO
• CHEN ANQING
• WANG LIGUO
• HU ZHIPING
• Cai shunda
• XIE BOYU

Assignees

• 鞍钢股份有限公司

Dates

Publication Date

20260512

Application Date

20260306

Claims (5)

1. 1. A feedforward control method for off-tracking of strip steel in a furnace of a Sendzimir method hot galvanizing unit is characterized by comprising the following steps: Step 1, obtaining steel grade and specification information of cold-rolled strip steel before the strip steel enters a furnace area of a Sendzimir method hot galvanizing unit; Step 2, setting a cold rolling incoming strip shape control target of the strip steel based on the grade and the width specification of the steel grade, wherein the strip shape control target comprises an I value allowable value and a single-side wave height allowable value; Step 3, setting a furnace zone tension coefficient based on the grade and thickness specification of the steel, and determining an actual tension value of the strip steel running in a furnace zone according to the furnace zone tension coefficient, wherein the furnace zone tension coefficient is the ratio of the tension value of a unit sectional area of the strip steel running in the furnace zone to the material yield strength of the strip steel; step 4, setting a furnace roller convexity value based on the grade and thickness specification of the steel grade; And 5, presetting the process parameters set in the steps 2 to 4 in a unit control system, enabling the strip steel to have process conditions matched with the current product specification before entering a furnace area, and executing the process parameters in a continuous production process so as to realize feedforward control of the deviation of the strip steel in the furnace.
2. 2. The feed-forward control method for off-tracking of strip steel in a furnace of a sendzimir method hot galvanizing unit according to claim 1, wherein in step 2: The steel grade level comprises a CQ level, a DQ level and a DDQ level; The width specification is divided into three sections of 900-1100 mm, 1100-1200 mm and 1200-1550 mm; CQ-grade strip steel: when the width is 900 to 1100mm, the I value is less than or equal to 12, and the wave height of one side is less than or equal to 6mm; when the width is 1100 to 1200mm, the I value is less than or equal to 9, and the wave height of one side is less than or equal to 5mm; an I value of 9 or less the wave height of one side is less than or equal to 5mm; DQ-stage strip steel: when the width is 900 to 1100mm, the I value is less than or equal to 8, and the wave height of one side is less than or equal to 4mm; when the width is 1100 to 1200mm, the I value is less than or equal to 7, and the wave height of one side is less than or equal to 3mm; an I value of 7 or less the wave height of one side is less than or equal to 3mm; DDQ grade strip steel: when the width is 900 to 1100mm, the I value is less than or equal to 7, and the wave height of one side is less than or equal to 2mm; when the width is 1100 to 1200mm, the I value is less than or equal to 6, and the wave height of one side is less than or equal to 2mm; an I value of less than or equal to 6 the wave height of one side is less than or equal to 2mm.
3. 3. The feed-forward control method for off-tracking of strip steel in a furnace of a sendzimir method hot galvanizing unit according to claim 1, wherein in step 3: The steel grade level comprises a CQ level, a DQ level and a DDQ level; the thickness specification is divided into three sections of 0.3-0.5 mm, 0.5-1.6 mm and 1.6-2.5 mm; CQ-grade strip steel with the thickness of 0.3-0.5 mm, the furnace area tension coefficient of 0.38-0.48, the thickness of 0.5-1.6 mm, the furnace area tension coefficient of 0.45-0.50 and the thickness of 1.6-2.5 mm, the furnace area tension coefficient of 0.50-0.52; DQ-level strip steel with the thickness of 0.3-0.5 mm, the furnace area tension coefficient of 0.47-0.52, the furnace area tension coefficient of 0.35-0.40 when the thickness is 0.5-1.6 mm, and the furnace area tension coefficient of 0.40-0.42 when the thickness is 1.6-2.5 mm; the DDQ grade strip steel has a furnace region tension coefficient of 0.52-0.63 when the thickness is 0.3-0.5 mm, a furnace region tension coefficient of 0.25-0.30 when the thickness is 0.5-1.6 mm, and a furnace region tension coefficient of 0.32-0.36 when the thickness is 1.6-2.5 mm.
4. 4. The feed-forward control method for off-tracking of strip steel in a furnace of a sendzimir method hot dip galvanizing unit according to claim 1, wherein in step 4: The steel grade level comprises a CQ level, a DQ level and a DDQ level; the thickness specification is divided into three sections of 0.3-0.5 mm, 0.5-1.6 mm and 1.6-2.5 mm; CQ-grade strip steel, wherein the furnace roller convexity value is 400-450 μm when the thickness is 0.3-0.5 mm, 450-500 μm when the thickness is 0.5-1.6 mm, and 500-600 μm when the thickness is 1.6-2.5 mm; DQ-level strip steel, wherein the furnace roller convexity value is 350-400 μm when the thickness is 0.3-0.5 mm, 400-450 μm when the thickness is 0.5-1.6 mm, and 450-500 μm when the thickness is 1.6-2.5 mm; The DDQ grade strip steel has a furnace roller convexity value of 300-350 μm when the thickness is 0.3-0.5 mm, a furnace roller convexity value of 350-400 μm when the thickness is 0.5-1.6 mm, and a furnace roller convexity value of 400-450 μm when the thickness is 1.6-2.5 mm.
5. 5. A feed-forward control method for off-tracking of strip steel in a furnace of a Sendzimir method hot dip galvanizing unit according to claim 2 or 3, characterized in that, When the strip steel is CQ grade, the width is 1000-1150 mm, the thickness is 0.3-0.5 mm, the I value is less than or equal to 9, the wave height is less than or equal to 5mm, the tension coefficient is 0.38-0.48, and the furnace roller convexity is 400-450 mu m; When the strip steel is DQ-level, 1050-1160 mm in width and 0.45-0.8 mm in thickness, setting an I value less than or equal to 7, a wave height less than or equal to 3mm, a tension coefficient of 0.35-0.47 and a furnace roller convexity of 350-422 mu m; When the strip steel is of DDQ grade, the width is 1080-112mm, the thickness is 0.48-1.2 mm, the I value is less than or equal to 6, the wave height is less than or equal to 2mm, the tension coefficient is 0.25-0.52, and the furnace roller convexity is 329-466 mu m.

Description

Feedforward control method for off-tracking of strip steel in furnace of Sendzimir method hot galvanizing unit Technical Field The invention relates to the technical field of cold rolling, in particular to a feedforward control method for off-tracking of strip steel in a furnace of a Sendzimir method hot galvanizing unit. Background The continuous hot dip galvanizing unit of the Sendzimir method is one of the main stream production modes of the wide high-quality hot dip galvanized steel sheet at present. The process is characterized in that cold-rolled strip steel firstly enters an open fire heating section (oxidation furnace) before a reducing atmosphere annealing furnace and is directly heated by gas flame. This process aims, on the one hand, at burning off the residual rolling oil on the strip surface and, on the other hand, at controlled oxidation of the strip surface to form a thin and dense iron oxide film, which is subsequently reduced to pure iron in the reduction zone, so that good coating adhesion is obtained. The method has the advantages that the temperature of the strip steel entering the zinc pot is higher than that of the zinc liquid, the heat load of the zinc pot can be obviously reduced, the service life of the pot body is prolonged, meanwhile, the zinc ash and zinc slag generation amount is greatly reduced, the zinc consumption is reduced, the aluminum content in the zinc liquid is easier to stably control, and the quality uniformity of a coating is improved. However, in actual production, a hot dip galvanizing unit based on the Sendzimir method has long faced a common technical problem, namely off tracking of the strip steel in the furnace. The strip steel is often deviated from the central line of the unit when running in a furnace zone and transversely moves towards an operation side or a transmission side under the influence of the difference of the width and thickness of the product and the yield strength and the fluctuation of the incoming plate shape. When the deviation is slight, the strip steel is not uniformly contacted with the furnace roller, so that quality defects such as poor plating thickness, surface scratch and the like are formed, and when the deviation is serious, secondary accidents such as strip steel scratching the furnace wall, folding, strip breakage and the like are directly caused. Particularly, the treatment process of the belt breakage accident in the furnace relates to high-risk operation links such as stopping and recovering energy media in the furnace area, cooling and heating the furnace body, entering limited space personnel, and the like, has huge potential safety hazards, and single accident often causes shutdown loss of a plurality of hours to more than ten hours, so that the control of the unit operation rate and the production cost is seriously restricted. Aiming at the problem of deviation of the band steel in the furnace, related technology is explored in the industry. For example, chinese patent application publication No. CN112446130a discloses a "strip steel deviation simulation system and control method for continuous hot dip galvanizing unit annealing furnace". According to the method, the process parameters of each process section and the strip steel incoming data are acquired, sampling points are set, the deviation factors and the deviation amounts of the sampling points are calculated, the deviation correction amounts of the sampling points exceeding a critical value are calculated, and the deviation correction amounts of the process sections are summarized to pre-regulate the deviation correcting roller cylinder. The scheme focuses on deviation prediction and dynamic deviation correction based on real-time sampling data, belongs to the field of feedback control or feedforward preconditioning, realizes that the accuracy of a deviation correcting roller executing mechanism and a simulation model is depended, corrects the deviation trend, and actively avoids the deviation from a process source. For another example, the Chinese patent with the publication number of CN108802749B provides a method for measuring the deflection of the strip steel in the hot galvanizing air knife section of the continuous strip steel. According to the scheme, the laser ranging sensor and the linear sliding table module are arranged on the air knife section, and the deviation amount is calculated by detecting the transverse and normal positions of strip steel, so that the position of the air knife is adjusted and the roller is corrected. The invention focuses on the deviation detection and the instant deviation correction of the air knife section, and the technical contribution is that the precision of the measuring means is improved, the personalized design and the feedforward setting of the technological parameters of the furnace area are not involved, and the systematic solution is not provided for the special furnace condition of the open fire heating section of