Efficient descaling method and system suitable for stainless steel by using high-European-life abrasives

Abstract

The invention relates to an efficient descaling method and system suitable for stainless steel by using a high-European-life abrasive. The descaling method comprises the steps that stainless steel is straightened; carrying out primary descaling on the straightened stainless steel by using a roller brush; carrying out secondary descaling on the stainless steel by using abrasive water jet; cleaning the stainless steel by using low-pressure water jet; the stainless steel is dried through an air knife; wherein martensitic stainless steel particles are used as abrasives for the abrasive water jet. The descaling system comprises a straightening device, a roller brush, an abrasive water spray head, a low-pressure water spray head and a drying device. According to the descaling method and system, a high-speed roller brush and abrasive water jet process route is adopted, the high-speed roller brush process removes most of oxidation layers easy to remove, the abrasive water jet process removes residual oxidation layers and dechroming layers, and the descaling efficiency is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of stainless steel surface treatment, and relates to a cold stainless steel acid-free descaling method, and in particular to an efficient descaling method and system for stainless steel using a high Owen life abrasive. Background Art

[0002] During the steel production process, due to the presence of iron oxide scale on the surface of the steel, various product defects such as pits, pitting, and iron oxide indentation are generated on the steel surface. Therefore, it is necessary to remove the iron oxide scale completely, and this process is called descaling. During the hot rolling and heat treatment process, a complex oxide layer structure (iron oxide, chromium oxide, chromium-nickel spinel) and a dechromized layer are formed on the surface of stainless steel at the same time. This complex surface structure brings challenges to the descaling of stainless steel.

[0003] In the existing descaling technology, high-pressure water and / or descaling machines are mainly used. In the technology using high-pressure water, abrasives are usually added to improve the descaling effect and efficiency of the water jet. For example, Chen Keqing et al. published a paper entitled "Research on Descaling Process of Stainless Steel Strip with Abrasive Water Jet", which disclosed a scheme for descaling stainless steel using abrasive water jets, and studied the influence of descaling process parameters on the descaling effect, and obtained the optimal descaling parameter combination of stainless steel strip abrasive water jets, including working pressure, water flow, strip moving speed, target distance and abrasive concentration. However, the abrasive used in this scheme has a low lifespan, high descaling cost, abrasive particles are easily embedded in the matrix, the surface quality is poor, and the dechroming layer is not considered. Liu Jiawei published a paper titled "Study on Descaling and Surface Integrity of 2205 Duplex Stainless Steel by Abrasive Water Jet", in which he systematically studied the erosion wear mechanism and the influence of process parameters on descaling effect and work hardening in abrasive water jets with two abrasives, martensitic stainless steel shot and garnet sand. The focus was on the influence of abrasive particle size and working pressure on the descaling quality and work hardening of 2205 duplex stainless steel. However, the scheme disclosed in the paper only uses abrasive water jet for descaling, and the descaling efficiency is low. Cao Haoxiang et al. published a patent for "High-efficiency Abrasive Jet Method and Device" (CN96118395), which is applied to the descaling of rods and wires. It mainly describes abrasive water jets and introduces a nozzle structure in detail. However, since the scheme is aimed at descaling rods and wires, it lacks consideration of the dechroming layer and does not have specific abrasive water jet descaling process parameters. Zeng Yonglong and others published a patent for "A medium- and high-pressure abrasive descaling device and process for the surface of continuous casting and rolling steel billets" (CN202210168457). A certain proportion of abrasive grains are mixed into the medium- and high-pressure water of 8-12MPa, and the jet mass flow rate is increased while ensuring that the water jet produces a thermal explosion effect when encountering the red steel billet, thereby exerting the crushing and abrasive effect of the abrasive grains, increasing the descaling impact force and high-frequency erosion and grinding capabilities. However, this scheme is to treat the hot surface, and the abrasive particles are selected from quartz sand with a mesh size of 80 to 120, which can easily cause adverse effects on the surface of the steel. There are also some technologies that use high-pressure water and descaling machines in combination. For example, Fang Xin and others published "an acid-free descaling system and descaling method for obtaining excellent surface morphology" (CN202210168457), which is applied to the surface treatment technology of metal plates, wherein a grinding device, a drying device and an oiling device are arranged between the jet generating device and the second pinching and steering roller, and the grinding device includes an extrusion grinding plate and a second cleaning device. However, this scheme lacks consideration for the dechroming layer because it is aimed at descaling metal plates. Bai Zhenhua et al. published a patent for "EPS parameter design method suitable for green and efficient pickling-free technology" (CN202310617210), and the green and efficient pickling-free technology (GEPF) disclosed in the patent first removes the Fe2O3 layer and Fe3O4 layer of the outer layer of FeO oxide scale through a smooth surface cleaning technology SCS (mechanical roller brush), and then removes the FeO oxide scale through the surface ecological pickling technology EPS (wet shot blasting), and finally polishes the surface of the strip through the secondary smooth surface cleaning technology SCS to ensure the surface roughness of the strip. However, this scheme is not a process developed for stainless steel descaling, and does not consider the dechroming layer. Summary of the invention

[0004] In view of the above problems of the prior art, an object of the present invention is to provide a novel cold stainless steel acid-free descaling method, which can simultaneously remove the stainless steel oxide layer and the dechromium layer, significantly improve the descaling efficiency and significantly reduce the descaling cost.

[0005] In order to achieve the above-mentioned object, the present invention provides an efficient descaling method for stainless steel using a high Owen life abrasive, comprising the following steps: straightening the stainless steel; descaling the straightened stainless steel once by means of a roller brush; descaling the stainless steel that has been descaled once for a second time by means of an abrasive water jet; cleaning the stainless steel that has been descaled twice by means of a low-pressure water jet; and drying the cleaned stainless steel by means of an air knife; wherein the abrasive water jet uses martensitic stainless steel particles as abrasive.

[0006] From the above, the efficient descaling method of the present invention uses a roller brush to remove more than 90% of the easily removable oxides on the surface of stainless steel, so that the abrasive water jet can better act on the dechroming layer treatment later, reducing the subsequent abrasive water jet descaling pressure and improving the overall descaling efficiency. The efficient descaling method of the present invention also uses martensitic stainless steel particles as abrasives. Compared with brittle abrasives such as garnet sand and steel sand, martensite has high impact toughness. Martensitic stainless steel particles have good corrosion resistance and are not easy to rust in a humid environment for a long time. They have higher hardness in stainless steel products. Therefore, they are used in stainless steel descaling with higher wear resistance and good descaling efficiency. Combined with a roller brush, the martensitic stainless steel particles in the present invention show an extremely high Owen life, and their Owen life exceeds 3,000 times, which greatly reduces the overall cost of the descaling method of the present invention.

[0007] In a possible implementation of the method of the present invention, the moving speed of the stainless steel material is 4-10 m / min.

[0008] In a possible implementation of the method of the present invention, the linear speed of the roller brush is 60-80 m / s, and the roller brush applies a positive pressure of 2-4 kg to the stainless steel strip.

[0009] In a possible implementation of the method of the present invention, the pressure of the abrasive water jet is 60-100 MPa, the target distance is 70-110 mm, and the spray angle is 70°-85°.

[0010] In a possible implementation of the method of the present invention, the martensitic stainless steel particles are wire-cut particles with a particle size of 0.4-1.0 mm.

[0011] In a possible implementation of the method of the present invention, the low-pressure water jet is fan-shaped and has a pressure of 1.5-3 MPa.

[0012] Based on the above, further optimizing the efficient descaling method of the present invention will help to further improve the descaling efficiency of stainless steel, further reduce the descaling cost, and improve the descaling effect, so that Sa3 level can be achieved.

[0013] The present invention also provides an efficient descaling system for stainless steel using a high Owen life abrasive, comprising: a straightening device, which is configured to straighten the stainless steel; at least one pair of roller brushes arranged oppositely, which are configured to perform a primary descaling on the straightened stainless steel on both sides of the stainless steel; at least one pair of abrasive water jets arranged oppositely, which are configured to spray abrasive water jets on both sides of the stainless steel to perform a secondary descaling on the stainless steel that has undergone the primary descaling; at least one pair of low-pressure water jets arranged oppositely, which are configured to spray low-pressure water jets on both sides of the stainless steel to clean the stainless steel that has undergone the secondary descaling; and a drying device, which is configured to generate wind knives on both sides of the stainless steel to dry the cleaned stainless steel; wherein the abrasive water jet uses martensitic stainless steel particles as abrasives.

[0014] The efficient descaling system of the present invention uses a roller brush to remove more than 90% of the easily removable oxides on the surface of stainless steel, so that the abrasive water jet can subsequently act better on the dechroming layer treatment, reducing the subsequent abrasive water jet descaling pressure and improving the overall descaling efficiency. The efficient descaling system of the present invention also uses martensitic stainless steel particles as abrasives. Compared with brittle abrasives such as garnet sand and steel sand, martensite has high impact toughness. Martensitic stainless steel particles have good corrosion resistance and are not easy to rust in a humid environment for a long time. They have a higher hardness among stainless steel products. Therefore, they have higher wear resistance and good descaling efficiency when used in stainless steel descaling. Combined with a roller brush, the martensitic stainless steel particles in the present invention show an extremely high Owen life, and their Owen life exceeds 3,000 times, which greatly reduces the overall cost of the descaling system of the present invention.

[0015] In a possible implementation of the system of the present invention, it also includes a first pinch roller located upstream of the straightening device, an unwinding device located upstream of the first pinch roller, a second pinch roller located downstream of the drying device, and a winding device located downstream of the second pinch roller.

[0016] In a possible implementation of the system of the present invention, the moving speed of the stainless steel material is 4-10 m / min.

[0017] In a possible implementation of the system of the present invention, the linear speed of the roller brush is 60-80 m / s, and the roller brush applies a positive pressure of 2-4 kg to the stainless steel strip.

[0018] In a possible implementation of the system of the present invention, the pressure of the abrasive water jet is 60-100 MPa, the target distance is 70-110 mm, and the jet angle is 70°-85°.

[0019] In a possible implementation of the system of the present invention, the martensitic stainless steel particles are wire-cut particles with a particle size of 0.4-1.0 mm.

[0020] In a possible implementation of the system of the present invention, the low-pressure water nozzle is a fan-shaped nozzle with a pressure of 1.5-3 MPa.

[0021] The above contents of the present invention will be more clearly understood in the following description of multiple embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings of the present invention will be provided below. These drawings are only for embodying the present invention in a more intuitive form. They are exemplary and are not intended to limit the scope of the present invention.

[0023] Figure 1 A schematic flow chart of an embodiment of a highly efficient descaling method according to the present invention is shown.

[0024] Figure 2 A structural schematic diagram of an embodiment of a high-efficiency descaling system according to the present invention is shown.

[0025] Figure 3 This is the surface structure diagram of 2205 duplex stainless steel before descaling.

[0026] Figure 4 This is the surface oxidation morphology of 2205 duplex stainless steel before descaling.

[0027] Figure 5 This is a surface comparison of 2205 duplex stainless steel after descaling.

[0028] Figure 6 This is the morphology of the descaling area of ​​2205 duplex stainless steel after descaling.

[0029] Figure 7 This is the energy spectrum of the surface of 2205 duplex stainless steel after descaling. DETAILED DESCRIPTION

[0030] To make the present invention easier to understand, the present invention is further described below in conjunction with specific examples. The experimental methods described in the present invention are conventional methods unless otherwise specified; the materials described are commercially available unless otherwise specified. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present invention. If there is any inconsistency, the meaning described in this specification or the meaning derived from the contents recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0031] In order to accurately describe the technical contents of the present invention and to accurately understand the present invention, the following explanations or definitions are given for the words and terms used in this specification before describing the specific implementation methods.

[0032] The words "one embodiment" or "an embodiment" as used in this specification means that a particular feature, step, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, the particular features, steps, or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure.

[0033] The term "abrasive water jet" used in the specification and claims refers to a method of processing materials by using high-speed water flow to drive abrasive particles to spray at high speed. According to the mixing method of abrasive particles and water, it is divided into: front mixing type, rear mixing type and external mixing type. The rear mixing type abrasive water jet (hereinafter referred to as abrasive water jet) is a high-speed water flow and abrasive particles are mixed in a mixing chamber, and sprayed through an abrasive nozzle to form an abrasive water jet.

[0034] The term "Owen life" used in the specification and claims is a parameter that can directly reflect the wear resistance of abrasive particles. A high Owen life means high wear resistance and high quality. It is generally believed that abrasives with an Owen life of more than 2600 are high Owen life abrasives. The martensitic stainless steel particles involved in the present invention have an Owen life of about 3000, which belongs to high Owen life abrasives. The 100% replacement test process of Owen life is as follows: ① Put 100g of abrasive sample into the Owen life tester; ② Circulate until the sample consumption reaches about 20%, and stop the Owen life tester; ③ Take out the sample, sieve the sample with a mesh screen, remove the undersize, weigh the mass of the oversize, and record the loss and cumulative loss; ④ Add the original abrasive sample to make the mass of the oversize reach 100g again, and then circulate: ⑤ Repeat ① to ④ until the cumulative loss is ≥100g; ⑥ The calculation formula of Owen life by 100% replacement method is: Owen life = total number of cycles (number of tests each time / final loss) × (cumulative loss% - 100).

[0035] During the hot rolling and heat treatment process, a complex oxide layer structure (iron oxide, chromium oxide, chromium-nickel spinel) + dechroming layer is formed on the surface of stainless steel. Chemical pickling and descaling of stainless steel is difficult (pickling solution HF+HNO3), which causes serious environmental pollution, a harsh working environment, and high equipment maintenance costs. Conventional abrasive water jet acid-free descaling generally uses pomegranate sand, steel sand and other low-Owen life abrasives (Owen life 2-3 times), with high comprehensive descaling costs and poor surface quality. Abrasive water jets use steel particles as abrasives. Since the hardness of steel particles is lower than that of garnet sand, the descaling efficiency is low. Carbon steel abrasives are easily oxidized and rusted when in contact with water. The existing abrasive water jet descaling process only removes the surface oxide layer and does not consider the treatment of the stainless steel dechroming layer.

[0036] The present invention focuses on the efficient and low-cost removal of the oxide layer and the dechromized layer on the surface of stainless steel. The present invention designs a process route of high-speed roller brush + abrasive water jet. The high-speed roller brush process removes most of the oxide layers that are easy to remove, and the abrasive water jet process removes the residual oxide layer and the dechromized layer, which significantly improves the descaling efficiency. The present invention uses martensitic stainless steel particles with a high Owen life as abrasive (with a roller brush, the Owen life exceeds 3000 times), which meets the requirements for stainless steel descaling and significantly reduces the comprehensive cost of descaling.

[0037] See also Figure 1 The efficient descaling method of the present invention comprises the following steps: S101: unwinding and straightening the stainless steel material, S102: descaling the straightened stainless steel material once with the aid of a high-speed roller brush, S103: descaling the stainless steel material that has undergone the primary descaling with the aid of a high-pressure water jet, S104: cleaning the surface of the stainless steel material that has undergone the secondary descaling with the aid of a low-pressure water jet, S105: drying the cleaned stainless steel material with the aid of a high-speed air knife, and S106: rewinding the dried stainless steel material. It is understood that in the efficient descaling method of the present invention, when the initial form of the stainless steel material is a non-coiled material, the unwinding in step S101 and the rewinding in step S106 can be omitted or replaced.

[0038] See also Figure 2The high-efficiency descaling system of the present invention comprises an unwinding device for unwinding a stainless steel coil, a pinch roller 1 for conveying the unwinding stainless steel coil, a straightening device configured to straighten the stainless steel, a pair of relatively arranged high-speed roller brushes configured to perform a primary descaling on the straightened stainless steel on both sides of the stainless steel, two pairs of relatively arranged abrasive water nozzles configured to spray abrasive water jets on both sides of the stainless steel to perform a secondary descaling on the stainless steel that has undergone the primary descaling, a pair of relatively arranged low-pressure water nozzles configured to spray low-pressure water jets on both sides of the stainless steel to clean the stainless steel that has undergone the secondary descaling, a drying device configured to generate wind knives on both sides of the stainless steel to dry the cleaned stainless steel, a pinch roller 2 for conveying the dried stainless steel coil, and a winding device for winding the stainless steel coil. It is understandable that in the efficient descaling system of the present invention, when the initial form of the stainless steel material is a non-coiled material, the unwinding device, the pinch roller 1, the pinch roller 2 and the winding device can be omitted or replaced. In addition, the number of roller brushes, abrasive water nozzles and low-pressure water nozzles are exemplary and can be adjusted according to actual needs. It is worth noting that in the efficient descaling system of the present invention, the spray angle of the abrasive water nozzle is greater than the spray angle of the low-pressure water nozzle.

[0039] <Example 1>

[0040] The pinch roller 1 controls the stainless steel strip to move at a speed of 5m / min. The high-speed roller brush has a linear speed of 70m / s and a pressure of 3kg. 410 martensitic stainless steel wire cutting particles are used, with a particle size of 0.6mm, a working pressure of 85MPa, an inner diameter of a high-pressure water nozzle of 3.6mm, a target distance of 85mm, a jet angle of 80°, and abrasive mass concentration of 22%. The surface after descaling reaches Sa3 level. The specific steps are as follows:

[0041] Step 1: Uncoil the coil using an uncoiler.

[0042] Step 2: The pinch roller 1 conveys the stainless steel strip into the straightening machine at a feeding speed of 10m / min.

[0043] Step 3: After the straightening machine straightens the plate and strip, it is sent to the high-speed roller brush descaling station.

[0044] Step 4: The roller brushes are symmetrically arranged on the upper and lower surfaces of the plate strip. Use a φ150mm metal roller brush with a rotation speed of 9000n / min and a hydraulically controlled pressure of 3kg between the roller brush and the plate strip.

[0045] Step 5: Two rows of abrasive water jet nozzles A and B are set on the upper and lower surfaces of the plate strip, respectively. The spacing between rows A and B is 400mm, the spacing between adjacent nozzles A1 and A2 in row A is 25mm, and the spacing between adjacent nozzles B1 and B2 in row B is 25mm. Nozzle B1 is arranged on the center line of nozzles A1 and A2. The vertical height of the abrasive water jet nozzle outlet is 85mm from the plate surface, and the nozzle outlet direction is 80° to the vertical direction of the plate surface. The working pressure of the abrasive water jet is 85MPa, the inner diameter of the high-pressure water nozzle is 3.6mm, and the flow rate of 0.6mm martensitic stainless steel particles is 75kg / min.

[0046] A single row of low-pressure cleaning fan-shaped nozzles (row C) is set on the upper and lower surfaces of the plate strip. The spacing between row C and row B is 400mm, the spacing between row C and row A is 800mm, and the spacing between adjacent nozzles C1 and C2 in row C is 100mm. The outlet of the low-pressure cleaning fan-shaped nozzle is 110mm vertically above the plate surface, and the nozzle outlet direction is 40° to the vertical direction of the plate surface. The working pressure of low-pressure cleaning is 2MPa.

[0047] Step 6: Set up wind knives on the upper and lower sides of the strip to quickly dry the surface.

[0048] Step 7: The pinch roller 2 conveys the strip into the winder.

[0049] Step 8: The winder is used for winding.

[0050] <Example 2>

[0051] The pinch roller 1 controls the stainless steel strip moving speed of 6m / min. The high-speed roller brush line speed is 70m / s and the pressure is 3kg. 410 martensitic stainless steel wire cutting particles are used, the particle size is 0.7mm, the working pressure is 85MPa, the inner diameter of the high-pressure water nozzle is 3.8mm, the target distance is 92mm, the injection angle is 85°, and the abrasive mass concentration is 33%. The surface after descaling reaches Sa3 level. The specific steps are as follows:

[0052] Step 1: Uncoil the coil using an uncoiler.

[0053] Step 2: The pinch roller 1 conveys the stainless steel strip into the straightening machine at a feeding speed of 10m / min.

[0054] Step 3: After the straightening machine straightens the plate and strip, it is sent to the high-speed roller brush descaling station.

[0055] Step 4: The roller brushes are symmetrically arranged on the upper and lower surfaces of the plate strip. Use a φ150mm metal roller brush with a rotation speed of 9000n / min and a hydraulically controlled pressure of 3kg between the roller brush and the plate strip.

[0056] Step 5: Two rows of abrasive water jet nozzles A and B are set on the upper and lower surfaces of the plate strip, respectively. The spacing between rows A and B is 400mm, the spacing between adjacent nozzles A1 and A2 in row A is 28mm, and the spacing between adjacent nozzles B1 and B2 in row B is 28mm. Nozzle B1 is arranged on the center line of nozzles A1 and A2. The vertical height of the abrasive water jet nozzle outlet is 80mm from the plate surface, and the nozzle outlet direction is 85° to the vertical direction of the plate surface. The working pressure of the abrasive water jet is 85MPa, the inner diameter of the high-pressure water nozzle is 3.8mm, and the flow rate of 0.7mm martensitic stainless steel particles is 92kg / min.

[0057] A single row of low-pressure cleaning fan-shaped nozzles (row C) is set on the upper and lower surfaces of the plate strip. The spacing between row C and row B is 400mm, the spacing between row C and row A is 800mm, and the spacing between adjacent nozzles C1 and C2 in row C is 100mm. The outlet of the low-pressure cleaning fan-shaped nozzle is 110mm vertically above the plate surface, and the nozzle outlet direction is 40° to the vertical direction of the plate surface. The working pressure of low-pressure cleaning is 2MPa.

[0058] Step 6: Set up wind knives on the upper and lower sides of the strip to quickly dry the surface.

[0059] Step 7: The pinch roller 2 conveys the strip into the winder.

[0060] Step 8: The winder is used for winding.

[0061] <Example 3>

[0062] The pinch roller 1 controls the stainless steel strip moving speed of 9m / min. The high-speed roller brush line speed is 79m / s, and the pressure is 3.5kg. 410 martensitic stainless steel wire cutting particles are used, with a particle size of 0.9mm, a working pressure of 100MPa, an inner diameter of the high-pressure water nozzle of 4.5mm, a target distance of 110mm, a jet angle of 75°, and abrasive mass concentration of 35%. The surface after descaling reaches Sa3 level. The specific steps are as follows:

[0063] Step 1: Uncoil the coil using an uncoiler.

[0064] Step 2: The pinch roller 1 conveys the stainless steel strip into the straightening machine at a feeding speed of 20m / min.

[0065] Step 3: After the straightening machine straightens the plate and strip, it is sent to the high-speed roller brush descaling station.

[0066] Step 4: The roller brushes are symmetrically arranged on the upper and lower surfaces of the plate strip. Use a φ200mm metal roller brush with a rotation speed of 7500n / min and a hydraulically controlled pressure of 3.5kg between the roller brush and the plate strip.

[0067] Step 5: Two rows of abrasive water jet nozzles A and B are set on the upper and lower surfaces of the plate strip, respectively. The spacing between rows A and B is 400mm, the spacing between adjacent nozzles A1 and A2 in row A is 40mm, and the spacing between adjacent nozzles B1 and B2 in row B is 40mm. Nozzle B1 is arranged on the center line of nozzles A1 and A2. The vertical height of the abrasive water jet nozzle outlet is 110mm from the plate surface, and the nozzle outlet direction is 75° to the vertical direction of the plate surface. The working pressure of the abrasive water jet is 100MPa, the inner diameter of the high-pressure water nozzle is 4.5mm, and the flow rate of 0.9mm martensitic stainless steel particles is 150kg / min.

[0068] A single row of low-pressure cleaning fan-shaped nozzles (row C) is set on the upper and lower sides of the plate strip. The distance between row C and row B is 400mm, the distance between row C and row A is 800mm, and the distance between adjacent nozzles C1 and C2 in row C is 100mm. The outlet of the low-pressure cleaning fan-shaped nozzle is 110mm vertically above the plate surface, and the nozzle outlet direction is 40° to the vertical direction of the plate surface. The working pressure of low-pressure cleaning is 3MPa.

[0069] Step 6: Set wind knives on the upper and lower sides of the plate to quickly dry the surface.

[0070] Step 7: The pinch roller 2 conveys the strip into the winder.

[0071] Step 8: The winder is used for winding.

[0072] <Experimental Example 1>

[0073] The surface structure of 2205 duplex stainless steel before descaling is as follows Figure 3 As shown in Figure 4, the surface oxidation morphology of 2205 duplex stainless steel before descaling is shown in Figure 4. Figure 3 The middle position ① is the oxide layer, Position ② is the dechromed layer, position ③ is the substrate, and the components at each position are shown in Table 1.

[0074] Table 1 Composition of 2205 duplex stainless steel at different positions before descaling (wt, %) Location Cr Ni O C Mo Fe Oxide layer 20.8 - 28.3 2 - Bal. Chrome stripping layer 18.2 7.5 - 1.0 2.6 Bal. Matrix 21.7 7.8 - 1.5 2.0 Bal.

[0075] Surface comparison of 2205 duplex stainless steel after descaling Figure 5 As mentioned above, the morphology of the descaling area of ​​2205 duplex stainless steel after descaling is as follows: Figure 6 As shown, the surface of the descaled area reaches Sa3 level, and obvious metal flow occurs on the surface. Figure 7 The energy spectrum results of the surface of 2205 duplex stainless steel after descaling show that the dechromized layer has been removed.

[0076] The above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present invention, all of which belong to the scope of protection of the present invention.

Claims

1. An efficient descaling method for stainless steel using high Owen life abrasives, characterized in that: The following steps are involved: Straightening of stainless steel; Descaling the straightened stainless steel material by means of a roller brush; Performing secondary descaling on the stainless steel material that has been descaled once by means of an abrasive water jet; Cleaning the stainless steel material after secondary descaling by means of a low-pressure water jet; as well as Drying the cleaned stainless steel material by means of an air knife; Wherein, the abrasive water jet uses martensitic stainless steel particles as abrasive.

2. The efficient descaling method according to claim 1, characterized in that: The moving speed of the stainless steel material is 4-10 m / min.

3. The efficient descaling method according to claim 1, characterized in that: The linear speed of the roller brush is 60-80 m / s, and the roller brush applies a positive pressure of 2-4 kg to the stainless steel strip.

4. The efficient descaling method according to claim 1, characterized in that: The pressure of the abrasive water jet is 60-100 MPa, the target distance is 70-110 mm, and the jet angle is 70°-85°.

5. The efficient descaling method according to claim 1, characterized in that: The martensitic stainless steel particles are wire-cut particles with a particle size of 0.4-1.0 mm.

6. The efficient descaling method according to claim 1, characterized in that: The low-pressure water jet is fan-shaped and has a pressure of 1.5-3 MPa.

7. Use high Owen life abrasives for efficient descaling system of stainless steel, characterized by: include: A straightening device configured to straighten stainless steel; at least one pair of roller brushes arranged opposite to each other, configured to perform a descaling operation on the straightened stainless steel material on both sides of the stainless steel material; At least one pair of abrasive water jets disposed opposite to each other, configured to spray abrasive water jets on both sides of the stainless steel material to perform secondary descaling on the stainless steel material that has been descaled once; At least one pair of low-pressure water spray nozzles arranged opposite to each other, which are configured to spray low-pressure water jets on both sides of the stainless steel material to clean the stainless steel material after secondary descaling; as well as A drying device, which is configured to generate air knives on both sides of the stainless steel material to dry the cleaned stainless steel material; Wherein, the abrasive water jet uses martensitic stainless steel particles as abrasive.

8. The efficient descaling system according to claim 7, characterized in that: It also includes a first pinch roller located upstream of the straightening device, an unwinding device located upstream of the first pinch roller, a second pinch roller located downstream of the drying device, and a winding device located downstream of the second pinch roller.

9. The efficient descaling system according to claim 7, characterized in that: The linear speed of the roller brush is 60-80 m / s, and the roller brush applies a positive pressure of 2-4 kg to the stainless steel strip.

10. The efficient descaling system according to claim 7, characterized in that: The pressure of the abrasive water jet is 60-100 MPa, the target distance is 70-110 mm, and the jet angle is 70°-85°.

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