Surface corrosion-resistant modified steel plate for medium-thickness plate and manufacturing method of surface corrosion-resistant modified steel plate

Abstract

The invention discloses a surface corrosion-resistant modified steel plate of a medium-thickness plate and a manufacturing method of the surface corrosion-resistant modified steel plate. Alloy powder can be effectively and uniformly coated on the surface of a slab through a physical adsorption method on the surface of a continuous casting slab or the slab, and the surface corrosion-resistant modified steel plate is obtained through the process of heating the slab in a heating furnace. The alloy powder prefabricated on the surface of the plate blank can be fully melted and spread on the surface of the plate blank to form an alloy modified coating with a metallurgical bonding interface between the alloy modified coating and a plate blank base body, in the subsequent rolling process, the coating can uniformly extend along with deformation of the plate blank, and finally the alloy modified coating with excellent corrosion resistance on the surface of the steel plate is formed. The problem that a traditional carbon steel plate is not resistant to corrosion is remarkably solved, the anti-corrosion procedure in the steel structure machining and using process is reduced, and the environment-friendly and low-carbon steel structure machining process is achieved.

Description

Technical Field

[0001] This invention relates to the field of steel plate rust prevention technology, and in particular to a medium-thick plate with a surface corrosion-resistant modified steel plate and its manufacturing method. Background Technology

[0002] To delay the corrosion of carbon steel structures, common methods include painting, plastic coating, metal plating, and ceramic coating. However, these corrosion-resistant treatments require surface cleaning of the steel plates, including shot blasting, dust removal, degreasing, and phosphating. Rust can still occur during the intervals between each process. Therefore, to ensure effective coating, some users need to repeat these processes multiple times. Pre-coating the steel plate surface can effectively solve the corrosion problem during carbon steel structure processing, but it will affect the original cutting, bending, and welding properties of the steel plate. The corrosion-resistant coating process is usually carried out after the steel plate has been structurally spliced. The following problems still exist in the construction process: (1) For equipment or structures with small volume and relatively complex internal structure, the internal spraying process is relatively difficult and the effective coating area inside the structure is difficult to ensure; (2) For the corrosion-resistant treatment of the box structure with narrow internal space, workers need to carry out shot blasting and spraying work inside the box. In the hot summer, the construction conditions of the workers are very harsh, and the dust and emissions seriously threaten the health of the construction workers; (3) The coating layer is prone to aging during the construction and operation of the equipment. Bubbling, cracking, peeling and other damage not only fail to achieve effective corrosion protection at the damaged coating, but also easily aggravate corrosion, bringing risks to the operation of equipment; (4) Most spray coatings will cause VOC and other pollutant emissions to exceed the standard when spraying in an unclosed workshop or in the open air, causing great trouble to the enterprise's production; (5) If stainless steel (or stainless steel composite plate) with good corrosion resistance is used to replace ordinary carbon steel, although the above-mentioned problems in construction, efficiency and environmental protection can be solved, it will lead to high production costs for enterprises and compress the profit margin of enterprises.

[0003] Therefore, in order to address the above issues, it is necessary to develop a steel plate surface treatment technology in the field of carbon steel medium and heavy plates that can meet users' requirements for the corrosion resistance of structural steel plate surfaces without affecting users' subsequent processing and use. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a medium-thick plate with a surface corrosion-resistant modified steel plate and its manufacturing method. By performing a surface corrosion-resistant modification treatment on the medium-thick carbon steel plate before it leaves the factory, the problem of easy corrosion of existing carbon steel plate products during processing, use, and subsequent service is solved. At the same time, the advent of this product can reduce the number of processes and emissions in the downstream steel structure processing and manufacturing process, reduce production costs, improve production efficiency, and reduce VOC emissions.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A medium-thick plate with a corrosion-resistant modified surface and its manufacturing method are disclosed. The medium-thick plate with a corrosion-resistant modified surface is formed by coating the surface of the slab with corrosion-resistant nickel-based alloy powder with a diameter between 5-25 μm, and then spraying a layer of organosilicon high-temperature resistant resin.

[0006] Furthermore, the melting point of the nickel-based alloy powder is below 1250°C.

[0007] The present invention also discloses a method for manufacturing the corrosion-resistant modified steel plate on the surface of the medium-thick plate, the manufacturing method comprising the following steps: Step 1) Grind the surface of the slab to remove the oxide scale and expose the metal surface, and then rinse the ground surface clean. Step 2) Apply corrosion-resistant nickel-based alloy powder with a diameter between 5-25μm evenly to the surface of the slab after grinding by electrostatic, brushing or spraying. After the surface alloy coating dries and cures, spray a layer of high-temperature resistant silicone resin onto the surface. Step 3) The slab heating, descaling and rolling process is carried out according to the conventional heating process. During the heating process in the heating furnace, the alloy coating and the slab substrate form a metallurgical bond. After rolling, the slab is air-cooled to room temperature.

[0008] Furthermore, the nickel-based alloy is prepared into nickel-based alloy powder using a ball mill.

[0009] The beneficial effects of this invention are as follows: The medium-thick plate surface corrosion-resistant modified steel plate of this invention has excellent corrosion resistance. Unlike the previous anti-corrosion methods of carbon steel medium-thick plates, which used composite plate processing or downstream steel structure processing and manufacturing, this invention proposes a new long-lasting anti-corrosion coating method and anti-corrosion system. At the same time, it reduces the manufacturing cost of steel plates and improves the efficiency of downstream steel structure processing. Specifically, this is reflected in the following aspects: (1) Compared with traditional composite plates, the medium-thick plate surface corrosion-resistant modified steel plate of the present invention can ensure the corrosion resistance of the carbon steel medium-thick plate substrate with the minimum alloy coating thickness, while maximizing the efficiency of steel plate production in the manufacturing method. The traditional composite plate production process requires grinding the slab to be composited and welding the slab, which requires strict control of the production process. Moreover, in the subsequent rolling process of the composite steel plate, the thickness of the composite layer (corrosion-resistant layer) often cannot be maintained at the micron level, which will cause a certain degree of waste for the high-cost coating material, thereby increasing the overall cost of the composite steel plate. In contrast, the medium-thick plate surface corrosion-resistant modified steel plate of the present invention has a simple production process, and the corrosion-resistant coating on the surface of the steel plate can be adjusted according to the actual corrosion resistance requirements, reducing the waste of high-cost corrosion-resistant coating alloy materials and reducing the production cost of the steel plate.

[0010] (2) Compared with traditional laser cladding and thermal spraying alloy coating, the medium-thick plate surface corrosion-resistant modified steel plate of the present invention has the characteristics of high production efficiency and low construction cost.

[0011] (3) The corrosion-resistant alloy coating on the slab surface is achieved by melting and spreading on the slab surface during the slab heating process. This fully utilizes the heating process of the slab in the furnace, and the molten alloy layer forms a good metallurgical bond with the slab substrate. This prevents the steel plate from easily delaminating, cracking, or other failure modes during subsequent processing and use, significantly improving the corrosion resistance of the steel plate. At the same time, by utilizing the slab heating process to achieve alloy melting and coating, compared with melting and coating the finished steel plate surface, this invention significantly reduces energy consumption during the production process.

[0012] (4) The medium-thick plate surface corrosion-resistant modified steel plate of the present invention is subjected to long-term corrosion-resistant protection treatment on the surface of the steel plate before the medium-thick plate leaves the factory, eliminating the need for traditional shot blasting and rust removal and paint spraying processes at the downstream steel structure processing and manufacturing end, significantly improving the efficiency of steel structure processing and manufacturing, reducing the emission of volatile organic compounds in the anti-corrosion coating process of large steel structures, and realizing rust-free, high-efficiency, clean and green steel structure processing throughout the entire process.

[0013] (5) From the perspective of steel structure processing flow, traditional large steel structures require shot blasting for rust removal during processing, which places high quality requirements on the surface of the steel plate after shot blasting. However, there is a long process interval between shot blasting and primer spraying. This process interval makes the active surface after shot blasting prone to new corrosion, affecting the actual effect of anti-corrosion coating. Moreover, after the steel plate has been in service for a certain number of years, the surface coating will fail and needs to be recoated. The medium-thick plate surface corrosion-resistant modified steel plate of the present invention achieves the coverage of corrosion-resistant alloy coating on the carbon steel surface, giving the original carbon steel excellent long-term corrosion resistance. This allows the carbon steel plate to be truly paint-free during use, avoiding the repeated repair problems of traditional coating protection, reducing the emission of volatile organic compounds during the coating process, and improving the processing and manufacturing efficiency of the steel plate. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the embodiments. A medium-thick plate with corrosion-resistant modified surface steel plate is produced by coating the surface of the slab with corrosion-resistant nickel-based alloy powder with a diameter between 5-25 μm and a melting point below 1250℃, and then spraying a layer of organosilicon high-temperature resistant resin. The manufacturing method is described in the following three embodiments. Example 1

[0015] (1) Grind the surface of the continuously cast billet to remove the oxide scale and grind until the billet shows a metallic luster; (2) Clean the surface of the slab after grinding, remove the surface contamination caused by the emulsion during the grinding process, and clean the iron filings on the surface. (3) The ball-milled nickel-based alloy powder is uniformly sprayed onto the surface of the slab after grinding by electrostatic spraying, and then a layer of high-temperature resistant silicone resin is sprayed onto the surface. (4) After the silicone resin on the surface of the slab has cured, the slab is heated and rolled in the furnace according to the original steel plate production process, and the steel plate is air-cooled to room temperature. Example 2

[0016] (1) Grind the surface of the continuously cast billet to remove the oxide scale and grind until the billet shows a metallic luster; (2) Clean the surface of the slab after grinding, remove the surface damage caused by the emulsion during the grinding process, and clean the iron filings on the surface. (3) Add the ball-milled nickel-based alloy powder into an alcohol or ester solvent for mixing. Add appropriate amounts of silicone resin to make the surface alloy powder easy to form a film and cover the slab surface. Roll the powder onto the surface of the slab after grinding to make the alloy powder evenly cover the slab surface. Finally, spray a layer of high-temperature resistant silicone resin onto the steel plate surface. (4) After the silicone resin on the surface of the slab has cured, the slab is heated and rolled in the furnace according to the original steel plate production process, and the finished steel plate is air-cooled to room temperature. Example 3

[0017] (1) Grind the surface of the continuously cast billet to remove the oxide scale and grind until the billet shows a metallic luster; (2) Clean the surface of the slab after grinding, remove the surface dirt caused by the emulsion during the grinding process, and clean the iron filings on the surface. (3) Add 40% solid content of the ball-milled nickel-based alloy powder to an organic-inorganic hybrid alcohol or ester solvent for mixing. Add appropriate amount of silicone resin to make the surface alloy powder easy to form a film and cover the slab surface. Roller coating is used on the surface of the slab after grinding so that the alloy powder is evenly covered on the slab surface. Finally, a layer of high temperature resistant silicone resin is sprayed on the steel plate surface. (4) After the silicone resin on the surface of the slab has cured, the slab is heated and rolled in the furnace according to the original steel plate production process, and the finished steel plate is air-cooled to room temperature.

[0018] The above content is only used to illustrate the technical solution of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A medium-thick plate with a corrosion-resistant surface modified steel plate, characterized in that: The medium-thick plate with corrosion-resistant modified surface steel plate is formed by coating the surface of the slab with corrosion-resistant nickel-based alloy powder with a diameter between 5-25μm, and then spraying a layer of organosilicon high-temperature resistant resin.

2. The medium-thick plate surface corrosion-resistant modified steel plate according to claim 1, characterized in that: The melting point of the nickel-based alloy powder is below 1250°C.

3. The method for manufacturing the medium-thick plate surface corrosion-resistant modified steel plate according to claim 1 or 2, characterized in that: The manufacturing method includes the following steps: Step 1) Grind the surface of the slab to remove the oxide scale and expose the metal surface, and then rinse the ground surface clean. Step 2) Apply corrosion-resistant nickel-based alloy powder with a diameter between 5-25μm evenly to the surface of the slab after grinding by electrostatic, brushing or spraying. After the surface alloy coating dries and cures, spray a layer of high-temperature resistant silicone resin onto the surface. Step 3) The slab heating, descaling and rolling processes are carried out according to the conventional heating process, and after rolling, it is air-cooled to room temperature.

4. The method for manufacturing medium-thick plate surface corrosion-resistant modified steel plate according to claim 3, characterized in that: The nickel-based alloy was prepared into nickel-based alloy powder using a ball mill.