A process for controlling the core waviness of thin gauge strip coils

Abstract

The application provides a process method for controlling the wave shape of a thin-gauge strip steel coil core, and the process method comprises the following steps: based on a raw material strip steel of endless rolling, the raw material strip steel is subjected to main processes such as uncoiling, welding, scale breaking, pickling, skin passing, tension leveling, oiling and coiling to form a pickling and skin passing coil, and corresponding adjustments are taken for each process; wherein the convexity of the raw material is pre-controlled; the elongation and rolling force are controlled in the scale breaking, skin passing and tension leveling processes; the material used for the coiling drum of the coiler is adjusted, and the coiling tension in the coiling process is adjusted. The process method for controlling the wave shape of the thin-gauge strip steel coil core realizes the improvement of the wave shape of the pickling and skin passing coil core of the hot-rolled thin-gauge mild steel, improves the physical quality of the product, and improves the market competitiveness of the product.

Description

Technical Field

[0001] This invention relates to the field of thin strip steel production technology in continuous pickling and leveling units, and particularly to a process method for controlling the waviness of thin strip steel cores. Background Technology

[0002] With the continuous advancement of steel rolling technology, the performance of hot-rolled thin plates is approaching that of cold-rolled plates, making "hot rolling instead of cold rolling" technically feasible. The development of the endless rolling production process has enabled the production of domestically produced hot-rolled ultra-thin strip steel products. However, considering the characteristics of hot rolling production processes and the softer and thinner nature of the products, thin-gauge hot-rolled strip steel that has not undergone annealing processes suffers from severe core waviness after cold rolling, pickling, and coiling, especially for products with a thickness of ≤1.2mm. This results in numerous customer complaints about quality, affecting user acceptance of the products. Furthermore, the amount of reversal and revision in internal cross-cutting plans due to core waviness continues to increase. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a process method for controlling the waviness of thin-gauge strip cores, which improves the waviness of hot-rolled thin-gauge mild steel cores after pickling and smoothing, thereby enhancing product quality and market competitiveness.

[0004] To achieve the above objectives, the present invention provides a process method for controlling the waviness of thin-gauge strip cores. The process method includes the following steps: based on endless rolled raw strip steel, the strip steel is processed through main processes such as uncoiling, welding, descaling, pickling, leveling, tension straightening, oiling, and coiling to produce a pickled and leveled coil, while making corresponding adjustments to each process.

[0005] Among these measures, the convexity of the raw materials is pre-controlled; the elongation and rolling force are controlled during the scaling, leveling, and tensioning processes; the material used in the coiler drum is adjusted during the coiling process, and the coiling tension is also adjusted during the coiling process.

[0006] In the process of pre-controlling the convexity of raw materials, the convexity of the raw materials is controlled to be within 20 micrometers.

[0007] In the descaling, leveling, and tension straightening processes, the descaling machine uses the elongation mode with an elongation of 0.5%, the leveling machine uses the rolling force mode with a rolling force of 2000-2500KN, and the tension straightening machine uses the elongation mode with an elongation of 0.2%.

[0008] During the winding process, the winding machine drum is made of polyurethane rubber sleeve with a hardness controlled at HK60-70.

[0009] Among them, the winding tension mode is designed in segments during the winding process, with a thickness of ≤1.2mm and a winding tension setting L2:18-24KN.

[0010] Among them, the variable tension winding mode is adjusted and designed during the winding process. 1 / 2 L2 winding tension is used for the first 0-100 meters of the belt, 2 / 3 L2 winding tension is used for the first 100-200 meters of the belt, and the remaining length is restored to the set tension L2.

[0011] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0012] This invention is based on endless rolling with a thickness of 0.8-1.5mm, a yield strength of 220-280MPa, a raw material crown of 25-30 micrometers, and the pickling and leveling unit using the original design process control. The winding tension is 20-28KN, the scale breaking machine elongation is 0.8%, the leveling elongation is 1.5%, and the tension leveling machine elongation is 0.4%. After being wound into a coil with an inner circle of about 45 meters by the pickling and leveling unit, an uncertain wavy shape appears.

[0013] The process method for controlling the wavy shape of thin-gauge strip steel cores provided by this invention effectively improves the wavy shape of thin-gauge strip steel cores by optimizing the distribution of coiling tension and elongation. The wavy length of the core is ≤5 meters, which meets the customer's requirements for the product. That is, by optimizing and adjusting the hot-rolled thin-gauge raw materials and pickling and leveling processes, the wavy shape of hot-rolled thin-gauge strip steel cores is effectively improved, thereby effectively enhancing market competitiveness. Detailed Implementation

[0014] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, the structures and features of one embodiment may be advantageously incorporated into other embodiments.

[0015] One embodiment of the present invention provides a process method for controlling the waviness of thin-gauge strip cores. The process method includes the following steps: based on the raw strip steel rolled without end, the strip steel is processed through main processes such as uncoiling, welding, descaling, pickling, leveling, tension straightening, oiling, and coiling to produce a pickled and leveled coil. At the same time, corresponding adjustments are made to each process to improve the quality of the pickled finished strip steel coil.

[0016] Among these measures, the convexity of the raw materials is pre-controlled; the elongation and rolling force are controlled during the scaling, leveling, and tensioning processes; the material used in the coiler drum is adjusted during the coiling process, and the coiling tension is also adjusted during the coiling process.

[0017] It should be noted that, regarding the incoming raw materials, the convexity of the raw materials does not change after passing through the various processes of the pickling and leveling line. Therefore, in this embodiment, the convexity of the raw materials is pre-controlled to within 20 micrometers. In this way, during the winding process, the accumulated convexity of the strip and the reduced stress on the inner ring can be effectively released.

[0018] During the scaling, leveling, and tension straightening processes, the mechanical properties of the pickled coils will undergo work hardening, with little change in tensile deformation but significant change in compressive deformation. Therefore, in this embodiment, while ensuring the thickness of the finished product and the yield strength required by the customer, the scaling machine uses the elongation mode with an elongation of 0.5%, the leveling machine uses the rolling force mode with a rolling force of 2000-2500KN, and the tension straightening machine uses the elongation mode with an elongation of 0.2%.

[0019] It should be noted that the first influencing factor is the hardness of the drum: the lower the hardness of the drum material, the better the stress release effect on the inner ring. Therefore, in this embodiment, the nylon diameter increasing plate used in the winding machine drum, with a hardness of HK95-105, is replaced with a polyurethane rubber sleeve with a hardness controlled at HK60-70; this ensures the stability of the wound roll shape and effectively improves the stress release of the inner ring of the finished roll.

[0020] It should be noted that another influencing factor during winding is the winding tension: the smaller the winding tension, the smaller the accumulated stress deformation in the inner ring; therefore, in this embodiment, the winding tension mode is designed in segments, with a thickness ≤ 1.2mm and a winding tension setting L2: 18-24KN, which not only meets the operating requirements of the winding machine but also reduces the impact of winding tension; at the same time, this embodiment designs a variable tension winding mode, using 1 / 2L2 winding tension for the first 0-100 meters of the belt, using 2 / 3L2 winding tension for the first 100-200 meters of the belt, and restoring the set tension L2 for the remaining length.

[0021] In summary, the process method for controlling the wavy shape of thin-gauge strip steel cores provided by this invention effectively improves the wavy shape of thin-gauge strip steel cores by optimizing the distribution of coiling tension and elongation. The wavy length of the core is ≤5 meters, which meets the customer's requirements for the product. That is, by optimizing and adjusting the hot-rolled thin-gauge raw materials and pickling and leveling processes, the wavy shape of hot-rolled thin-gauge strip steel cores is effectively improved, thereby effectively enhancing market competitiveness.

[0022] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A process for controlling the core waviness of thin gauge strip steel coils characterized by: The process method comprises the following steps: based on the raw material strip steel of the headless rolling, through the main processes of opening, welding, descaling, pickling, leveling, straightening, oiling, coiling and the like, the pickling and leveling coil is prepared, and corresponding adjustment is adopted for each process; The convexity of the raw material is pre-controlled, the elongation and rolling force are controlled in the descaling, leveling and straightening processes, the material used for the coiling drum of the coiling machine is adjusted, and the coiling tension in the coiling process is adjusted; The raw material convexity is controlled within 20 microns in the pre-control process; The elongation mode is used for the descaling machine, the elongation is set to 0.5%, the rolling force mode is used for the leveling machine, the rolling force is set to 2000-2500KN, and the elongation mode is used for the straightening machine, and the elongation is set to 0.2%; The coiling tension mode is designed in sections in the coiling process, the thickness is ≯1.2mm, and the coiling tension is set to L2:18-24KN; The variable tension coiling mode is adjusted and designed in the coiling process, 1 / 2L2 coiling tension is used for the strip head 0-100m, 2 / 3L2 coiling tension is used for the strip head 100-200m interval, and the remaining length is set to the tension L2.

2. The process for controlling the core wave of thin gauge strip steel as claimed in claim 1 wherein: The coiling drum of the coiling machine is a polyurethane material rubber sleeve, and the hardness is controlled to HK60-70.