Novel efficient physical and chemical comprehensive steel surface treatment production line

Abstract

The invention provides a novel efficient physical and chemical comprehensive steel surface treatment production line. The novel efficient physical and chemical comprehensive steel surface treatment production line comprises an inlet section, a process section and an outlet section which are arranged in sequence. The inlet section comprises an uncoiler, a straightening machine, a crop shear and a corner shear which are arranged in sequence; the process section comprises an EPS descaling unit, a brush roll, a weak pickling tank, a wringing roll, a cleaning tank and a dryer which are arranged in sequence; and the outlet section comprises a tail shear, an edge shear, a tensioning roller, an oiling machine and a coiling machine which are arranged in sequence. Fe2O3 on the outermost layer of the surface of the steel strip is partially removed through a stretch bending and straightening machine, and part of Fe2O3, Fe3O4 on the middle layer and FeO on the innermost layer are removed through a water-sand mixing device. After the steel strip passes through the weak acid tank, the surface roughness of the steel strip is reduced, the steel strip is whitened, and the requirements of stainless steel and titanium plates are met. According to the production line, mechanical descaling and chemical steel plate beautifying can be effectively combined; the dephosphorization time is short, the environment-friendly effect is good, and the application range is wide. And equipment investment is saved, equipment accident points are reduced, and equipment maintenance cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of steel plate surface treatment, and in particular to a new type of highly efficient physical and chemical comprehensive steel surface treatment production line. Background Art

[0002] With the development of "replacing cold with heat", people's demand for steel plates is the material of hot-rolled steel plates, and the demand for surface quality similar to cold-rolled steel plates is increasing. The material (organization and performance) requirements are constantly improving, and the yield strength of steel plates is as high as 1200Mpa, and the tensile strength is 1500Mpa; and the required thickness of steel plates (6mm to 40mm) is also increasing. How to remove phosphorus from the surface of such high-strength and thick steel coils (plates) is also a research topic for industry insiders.

[0003] At present, there are two types of descaling methods for hot-rolled steel sheets (coils): chemical descaling and physical descaling. Chemical descaling is to soak the steel strip in organic acid (hydrochloric acid or sulfuric acid) for a certain period of time, so that the iron oxide scale reacts with the acid to remove the iron oxide scale; physical descaling is to remove the iron oxide scale by repeatedly bending the steel strip or hitting the steel plate surface with steel balls and water (mud), or using a brush roller to brush the iron oxide scale. However, there are the following problems with chemical descaling or physical descaling: Chemical descaling: Due to the thickness of the steel plate, it is difficult for the steel plate to form a natural curvature in a short distance in the acid tank. The length of the acid tank needs to be lengthened to achieve the arcing of the steel strip in the tank. In addition, due to the increase in the distance of the acid tank and the thickness of the steel plate, the holding force of the squeeze roller needs to be increased, resulting in abnormal expansion of the equipment of the entire line and unstable pickling quality, which is very likely to cause over-pickling or under-pickling. And this method has a large environmental pollution. Pure chemical dephosphorization (such as push-pull shallow tank turbulent pickling device) because the acid enters the acid tank through side spraying and bottom spraying, the turbulence under the steel strip is higher than the turbulence on the upper surface, resulting in different pickling quality on the upper and lower surfaces. It is easy to cause under-pickling on the upper surface or over-pickling on the lower surface (or increased iron loss). Because pickling is a chemical reaction between hydrochloric acid and steel strip to cause the oxide scale to peel off, it takes a certain time (22-40 seconds), so the length of the acid tank is relatively long (generally about 80 meters). This leads to a longer production line, more equipment failure points, and higher investment and maintenance costs. Moreover, with the advancement of steel technology, the variety of cold-rolled products has been increasing, and the strength range of cold-rolled products has expanded from ≤400MPa to 800MPa or even above 1000MPa. The pickling line cannot meet the market demand for multiple varieties.

[0004] Physical descaling: The repeated bending method is only suitable for mild steel. For high-strength steel or thick plates, it is impossible to achieve this due to low elongation or large bending radius. The method of hitting the surface of the steel plate with steel balls and water (mud) can remove the surface oxide scale, but the removal speed is slow and the production cost is high. In addition, the oxide scale on the side of the steel plate is difficult to remove (such as EPS, production line) and the surface roughness of the steel plate is large, which makes it difficult to meet the customer's requirements for the surface quality of the steel plate. Pure brush rollers can also remove the oxide scale (such as skinning), but due to the unevenness of the plate surface, the brushing amount of the roller surface is different. The steel plate produced by the brush roller process has color difference, and there is serious color difference in subsequent processing (such as galvanizing). The product quality is unstable and cannot meet user needs. The production cost is high. Summary of the invention

[0005] Based on the shortcomings of pure chemical and physical phosphorus removal methods, the purpose of this application is to design a phosphorus removal device that combines physical methods with weak chemical reactions, so that the surface quality requirements of steel plates can be met while environmental pollution can be minimized. The upper and lower surface quality of the steel strip can be consistent, the iron oxide scale can be quickly peeled off, the production line can be shortened, and the equipment failure rate can be low.

[0006] In order to achieve the above-mentioned purpose, the present application provides a novel and efficient physical and chemical integrated steel surface treatment production line, comprising an inlet section, a process section and an outlet section arranged in sequence; The inlet section includes an uncoiler, a straightener, a crop shear and a corner shear arranged in sequence; The process section includes an EPS descaling unit, a brush roller, a weak acid washing tank, a squeeze roller, a cleaning tank and a dryer arranged in sequence; The outlet section comprises a tail trimming shear, a side trimming shear, a tensioning roller, an oiling machine and a coiling machine which are arranged in sequence.

[0007] In one possible implementation, the new high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the EPS descaling unit includes 2-5 water-sand mixed phosphorus removal units.

[0008] In one possible embodiment, the new high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the process section is provided with an acid mist purification system, the acid mist purification system includes an acid mist washing tower, and the acid mist washing tower is connected to the water-sand mixed phosphorus removal units through an air duct.

[0009] In one possible implementation manner, the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the cleaning tank is a five-stage cascade countercurrent rinsing tank.

[0010] In one possible implementation manner, in the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the tensioning roller is a three-roller tension roller.

[0011] In one possible implementation manner, in the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the oiler is an electrostatic oiler.

[0012] In one possible implementation manner, in the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the straightening machine is a nine-roller straightening machine.

[0013] In one possible implementation manner, in the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, a thickness gauge is provided between the straightening machine and the cropping shears.

[0014] In one possible implementation manner, in the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, a stitching machine is provided on the rear side of the angle cutting shears.

[0015] In one possible implementation manner, in the novel high-efficiency physical and chemical integrated steel surface treatment production line provided by the present application, the brush roller is a silicon carbide brush roller.

[0016] Beneficial effects: The new high-efficiency physical and chemical integrated steel surface treatment production line of the present application uses a combination of physical and chemical methods to remove rust on the surface of the steel strip. The outermost layer of Fe2O3 on the surface of the steel strip is partially removed by the stretching and straightening machine, and the Fe3O4 in the middle layer of some Fe2O3 and the innermost layer of FeO are removed by the water-sand mixing device. After the steel strip passes through the weak acid tank, the surface roughness of the steel strip is reduced and the steel strip is whitened, meeting the needs of stainless steel and titanium plates. It can effectively combine mechanical descaling and chemical beautification of steel plates; the straightening machine is changed into a stretching and descaling machine to accelerate descaling; the strong acid tank is changed into a water-sand mixing dephosphorization device, which has a shorter dephosphorization time, better environmental protection effect, and a wider range of applications. At the same time, due to the shortening of the dephosphorization production line, it greatly saves equipment investment, reduces equipment accident points, and reduces equipment maintenance costs; especially for pickling manufacturers that could only produce ordinary carbon steel or thin specifications in the early stage, it provides a shortcut to expand the production of varieties and specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 It is a structural schematic diagram of a new type of highly efficient physical and chemical integrated steel surface treatment production line provided in an embodiment of the present application.

[0019] Description of Reference Numerals 10-entrance section; 11- Uncoiler; 12-Straightening machine; 13-Thickness gauge; 14-cropping shears; 15-steering pinch roller; 16-corner shears; 17-sewing machine; 18-pinch roller; 20-process section; 21-EPS descaling unit; 211-water-sand mixed phosphorus removal unit; 22-brush roller; 23-weak acid washing tank; 24- cleaning tank; 25-Drying machine; 26-pinch roller; 27- Looper; 30-exit section; 31- Tail cutting shears; 32-deviation correction pinch roller; 33- trimming shears; 34-pinch roller; 35- tension roller; 36-Electrostatic oiling machine; 37- Coiler. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0021] See also Figure 1 , the embodiment of the present application provides a novel high-efficiency physical and chemical integrated steel surface treatment production line, comprising an inlet section 10, a process section 20 and an outlet section 30 arranged in sequence; The main task of the entrance section 10 is to complete the uncoiling and threading of the steel coil, and to straighten and shear the irregular parts at the head and tail. The entrance section 10 mainly includes an uncoiler 11, a straightener 12 (preferably a nine-roller straightener 12), a head shear 14 and a corner shear 16 arranged in sequence.

[0022] Specifically, a thickness gauge 13 is provided between the straightening machine 12 and the crop shear 14. A steering pinch roller 15 is provided between the crop shear 14 and the corner shear 16, a stitching machine 17 is provided at the rear side of the corner shear 16, and a pinch roller 18 is provided at the rear side of the stitching machine 17.

[0023] The main task of the process section 20 is to use the EPS process and weak pickling to remove scale, and to clean and dry the steel coil. The process section 20 includes an EPS descaling unit 21, a brush roller 22 (preferably a silicon carbide brush roller 22), a weak pickling tank 23, a squeeze roller, a cleaning tank 24 (preferably a five-stage cascade countercurrent rinsing tank) and a dryer 25, which are arranged in sequence.

[0024] The EPS descaling unit 21 includes five water-sand mixed dephosphorization units 211, and the process section 20 is also provided with an acid mist purification system, which includes an acid mist washing tower connected to each water-sand mixed dephosphorization unit 211 through an air duct.

[0025] Specifically, a pinch roller 26 and a looper 27 are provided at the rear end of the dryer 25 .

[0026] The main tasks of the exit section 30 are to shear the strip width, correct the plate shape, apply oil and coil. The exit section 30 includes a tail shear 31, a trimming shear 33, a tension roller 35 (preferably a three-roll tension roller), an oiler (preferably an electrostatic oiler 36) and a coiler 37 which are arranged in sequence.

[0027] Specifically, a deviation-correcting pinch roller 32 is provided between the tail trimming shear 31 and the side trimming shear 33 , and pinch rollers 34 are provided between the side trimming shear 33 and the tensioning roller 35 and between the oiling machine and the coiling machine 37 .

[0028] When in use, the rust on the steel strip surface is removed by combining physical and chemical methods. The outermost layer of Fe2O3 on the steel strip surface is partially removed by the bending straightener, and the middle layer of Fe3O4 and the innermost layer of FeO are removed by the water-sand mixing device.

[0029] Compared with the prior art, the new high-efficiency physical and chemical integrated steel surface treatment production line of the embodiment of the present application reduces the pickling tank to one weak pickling tank, and adds an EPS descaling unit before the weak pickling tank. It can quickly peel off the iron oxide scale of the steel coil by combining mechanical methods and weak chemical reactions, and reduce harmful gas emissions.

[0030] The above production line has the following specific features: 1. Use water-sand mixture combined with weak acid phosphorus removal instead of strong acid washing phosphorus removal, which has very little harmful gas emissions and meets national environmental protection requirements.

[0031] 2. The nine-roller straightening machine adopts a large-pressure steel plate bending process to remove the outermost layer of Fe2O3 of the iron oxide scale and reduce the phosphorus removal load of sand and water.

[0032] 3. Through the silicon carbide brush roller on the steel plate surface, FeO is further eliminated and the roughness of the steel plate is reduced. The peaks of the steel plate after shot blasting are eliminated or reduced, the roughness is reduced, and the cold-rolled steel plate is near-rolled to meet the demand of "replacing cold with heat".

[0033] 4. Use weak acid cleaning to further reduce the roughness of steel and eliminate color difference of steel strip.

[0034] 5. Adopt five-stage countercurrent rinsing system: use hot desalted water for rinsing to obtain good rinsing effect, and ensure the surface cleaning quality of the strip by accurately controlling the conductivity in the last rinsing section.

[0035] 6. Smoke purification system: The acid-containing gas in the pickling process section is sent to the acid mist washing tower through the air duct for purification, then extracted by the fan and discharged into the atmosphere through the chimney.

[0036] 7. Use electrostatic oiler to precisely control the thickness and uniformity of the oil film.

[0037] 8. Use two-stage reverse rinsing to shorten the production line length, reduce investment and equipment failure rate.

[0038] In the description of the embodiments of the present application, it should be understood that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. The orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise precisely and specifically specified.

[0039] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein. For example, it is possible to implement in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A new type of efficient physical and chemical comprehensive steel surface treatment production line, characterized by: It includes an inlet section, a process section and an outlet section which are arranged in sequence; The inlet section includes an uncoiler, a straightener, a crop shear and a corner shear arranged in sequence; The process section includes an EPS descaling unit, a brush roller, a weak acid washing tank, a squeeze roller, a cleaning tank and a dryer arranged in sequence; The outlet section comprises a tail trimming shear, a side trimming shear, a tensioning roller, an oiling machine and a coiling machine which are arranged in sequence.

2. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: The EPS descaling unit includes 2-5 water-sand mixing phosphorus removal units.

3. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 2 is characterized in that: The process section is provided with an acid mist purification system, and the acid mist purification system comprises an acid mist washing tower, and the acid mist washing tower is connected to each water-sand mixed phosphorus removal unit through an air duct.

4. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: The cleaning tank is a five-stage cascade countercurrent rinsing tank.

5. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: The tension roller is a three-roller tension roller.

6. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: The oiler is an electrostatic oiler.

7. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: The straightening machine is a nine-roller straightening machine.

8. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: A thickness gauge is provided between the straightening machine and the cropping shears.

9. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: A sewing machine is provided at the rear side of the miter shears.

10. The new high-efficiency physical and chemical comprehensive steel surface treatment production line according to claim 1 is characterized in that: The brush roller is a silicon carbide brush roller.

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