Method for controlling bonding of cold-rolled ultra-thin strip steel
By adopting the process route of pickling-five continuous rolling combined unit and twenty-roll single-frame reversible rolling mill in the cold-rolling CQ grade extremely thin strip steel, combined with low temperature long annealing and hydrogen purge system, the problem of easy bonding of extremely thin strip steel in production is solved, and efficient and stable production is achieved.
Patent Information
- Application Number
- CN202510215099.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-05-30
AI Technical Summary
CQ-grade extremely thin strip steel is prone to bonding problems during production, which affects the product added value, hit rate and material yield, resulting in large losses.
The pickling-five continuous rolling combined unit was used for one cold rolling, followed by a 20-roll single-frame reversible rolling mill unit for secondary cold rolling until the target thickness, and a low-temperature long-term process and hydrogen purge system were used during the annealing process, and finally re-rolling and packaging were carried out.
It effectively controls the bonding problem of cold-rolled CQ grade extremely thin strip steel, improves production efficiency, meets the needs of efficient mass production, and stabilizes the production of products such as steel for battery shells and tinplate.
Smart Images
Figure CN120055026A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of steel rolling, in particular to the production of cold-rolled CQ grade ultra-thin steel coils, and in particular to a method for controlling the adhesion of cold-rolled ultra-thin strip steel. Background Art
[0002] At present, due to production factors such as curling tension, plate surface roughness, and annealing process, CQ-grade ultra-thin strip steel (thickness h≤0.25mm) frequently has bonding quality problems during production, which seriously affects product added value, hit rate, and yield rate, causing great losses.
[0003] In summary, the prior art has the following problems: CQ-grade ultra-thin strip steel is prone to adhesion during production. Summary of the invention
[0004] The invention provides a method for controlling the adhesion of cold-rolled ultra-thin strip steel, so as to solve the problem that ultra-thin strip steel of CQ grade is prone to adhesion during production.
[0005] To this end, the present invention provides a method for controlling the adhesion of cold-rolled ultra-thin steel strip, the method for controlling the adhesion of cold-rolled ultra-thin steel strip comprising the following steps:
[0006] The process route is: pickling-five-row rolling mill → primary cold rolling to intermediate cold hard coil → secondary cold rolling to target thickness with 20-high single-stand reversible rolling mill → bell-type annealing furnace → leveling → re-coiling → packaging;
[0007] The rewinding tension requirements of the twenty-high single-stand reversible rolling mill unit are as follows: when unloading the rewinding tension, the coiling tension is controlled according to the total tension of 1.0-1.3t;
[0008] The rewinding tension requirements of the twenty-high single-stand reversible rolling mill unit are as follows: when unloading the rewinding tension, the coiling tension is controlled according to the total tension of 1.0-1.3t.
[0009] Since the implementation of this method, the bonding problem of cold-rolled CQ grade ultra-thin strip steel has been effectively controlled (see Table 1 for comparative data), and CQ grade cold-rolled ultra-thin strip steel can meet the requirements of efficient mass production (currently, steel for battery shells, tinplate, etc. have been stably produced in large quantities).
[0010] Table 1 Comparison of bonding conditions before and after improvement
[0011] contrast Production Adhesion amount Adhesion rate % Before implementation 2620 218.44 8.34 After implementation 3025 21.18 0.7 BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is an annealing process curve diagram of an embodiment of the present invention; wherein the ordinate is temperature, in units of ° C, and the abscissa is time, in units of hours. DETAILED DESCRIPTION
[0013] To have a clearer understanding of the technical features, objectives, and effects of the present invention, the present invention is now described.
[0014] The present invention adjusts the process route from the following conventional process route 1 to process route 2:
[0015] Process route 1: Pickling - five - stand tandem cold rolling mill unit → Direct rolling of cold - rolled coil with the target thickness → Bell - type annealing furnace unit → Skin pass rolling → Rewinding → Packaging.
[0016] Process route 2: Pickling - five - stand tandem cold rolling mill unit → First cold rolling to intermediate cold - rolled coil → Twenty - high single - stand reversing mill unit (second cold rolling to the target thickness) → Bell - type annealing furnace unit → Skin pass rolling → Rewinding → Packaging.
[0017] (2) Requirements for the rewinding coiling tension of the twenty - high single - stand reversing mill unit: When discharging the rewinding tension, the coiling tension is controlled at a total tension of 1.0 - 1.3 t, preferably controlled at 1.2 t.
[0018] (3) Requirements for the surface roughness of the twenty - high single - stand reversing mill unit: High - roughness rolls are used for grinding, the surface roughness of the roll is required to be 0.7 - 1.0 μm, and the surface roughness of the sheet is 0.8 ≤ Ra ≤ 1.2 μm;
[0019] (4) For the steel coils produced by the twenty - high single - stand reversing mill unit, the bell - type annealing process adopts low temperature and long time as shown in Table 3.1 below, and the hydrogen purging system is shown in Table 3.2. The annealing process curve is as Figure 1 shown.
[0020] Table 3.1 Annealing process for CQ - grade extra - thin strip steel
[0021]
[0022]
[0023] Table 3.2 Hydrogen purging system
[0024] stage Purge time h <![CDATA[Purge flow rate m 3 / h]]> 350℃ start 20 20(±5) Specific embodiments
[0026] A specific application example of this case is taken as the production of extra - thin strip steel of grade DC01, with the composition shown in Table 3.3 and the specification of 0.25 mm * 1000 mm.
[0027] Table 3.3 DC01 chemical composition execution standard
[0028] Element C Si Mn P S As Alt content% ≤0.034 ≤0.03 ≤0.25 ≤0.022 ≤0.015 ≤0.06 0.02-0.05
[0029] According to the above process route 2, the specific implementation process is as follows:
[0030] 1. The thickness before cold rolling is 2.75 mm. First, it passes through the pickling-five continuous rolling combined unit and is cold rolled once to an intermediate cold hard coil with a thickness of 0.7 mm.
[0031] 2. It passes through the 20-high single stand reversible rolling mill unit and is cold rolled twice. The 0.7 mm is rolled to the target thickness of 0.25 mm in three passes. The working rolls of the 20-high rolling mill are ground high-roughness rolls with a roll surface roughness requirement of 0.7 - 1.0 μm, and the sheet surface roughness can reach 0.8 ≤ Ra ≤ 1.2 μm. The total coiling tension during 20-high recoiling is controlled according to 1.2 t.
[0032] 3. It enters the bell-type annealing furnace for production. The annealing process adopts the low-temperature long-time process, that is, the annealing holding temperature is 640 °C + the holding time is 14 h, as shown in Table 3.1.
[0033] 4. It enters the skin pass mill. The skin pass is automatically closed-loop controlled with an elongation of 0.7%. It enters the recoiling, trimming, slitting, and oiling process; the packaging process adopts fine packaging.
[0034] Implementation results: 1. When producing according to this full-process technology, all mechanical properties are qualified, as shown in Table 3.4, and all meet the customer requirements; 2. There is no sticking phenomenon on the strip surface. At present, ultra-thin strip steel has been mass-produced and is stably produced.
[0035] Table 3.4 Mechanical property values
[0036] Mechanical properties Yield strength MPa Tensile strength MPa Elongation % value 207 331 34.5
[0037] The above is only the schematic specific implementation manner of the present invention and is not intended to limit the scope of the present invention. The various components of the present invention can be combined with each other under the condition of non-conflict. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.
Claims
1. A method for controlling the adhesion of cold-rolled ultra-thin strip steel, characterized in that: The method for controlling the bonding of cold-rolled ultra-thin strip steel comprises the following steps: The process route adopts: pickling-five-row continuous rolling combined unit, primary cold rolling to intermediate cold hard coil, secondary cold rolling to target thickness with 20-high single-stand reversible rolling mill unit, bell-type annealing furnace unit, flattening, re-coiling, and packaging; The rewinding tension requirements of the twenty-high single-stand reversible rolling mill unit are as follows: when unloading the rewinding tension, the coiling tension is controlled according to the total tension of 1.0-1.3t; The rewinding tension requirements of the twenty-high single-stand reversible rolling mill unit are as follows: when unloading the rewinding tension, the coiling tension is controlled according to the total tension of 1.0-1.3t.
2. The method for controlling adhesion of cold-rolled ultra-thin steel strip according to claim 1, characterized in that: Hood annealing is adopted, and the hood annealing process is as follows: the first stage heating temperature is 450°C, the time is 2 hours; the low temperature platform temperature is 450°C, the time is 2 hours; the second stage heating temperature is 640°C, the time is 9 hours; the insulation temperature is 640°C, the time is 14 hours; the hood cooling temperature is 550°C, the time is 8 hours.
3. The method for bonding cold-rolled ultra-thin steel strip according to claim 1, characterized in that: Hydrogen purging is used. The hydrogen purging system is as follows: purging starts at 350℃, purging time is 20 hours, and purging flow rate is 20±5m 3 / h.
4. The method for controlling adhesion of cold-rolled ultra-thin steel strip according to claim 1, characterized in that: Finished product specifications 0.25mm*1000mm, the specific steps are: (1) After pickling and five-row rolling combined unit, the intermediate cold-hardened coil is cold-rolled once to a thickness of 0.7 mm; (2) Through the twenty-roller single-stand reversible rolling mill unit, the 0.7mm is rolled to the target thickness of 0.25mm in three passes by using secondary cold rolling; the working rolls of the twenty-roller mill use ground high-roughness rolls, the roll surface roughness requirement is 0.7-1.0μm, and the plate surface roughness can reach 0.8≤Ra≤1.2μm. The total coiling tension is controlled according to 1.2t during the twenty-roller rewinding; (3) Enter the bell-type annealing furnace for production. The annealing process adopts a low-temperature and long-time process, that is, the annealing holding temperature is 640℃ + the holding time is 14h; (4) Entering the leveling unit, the leveling adopts 0.7% elongation automatic closed-loop control.