Selenium-containing heat-crack-resistant steel and processing method thereof

Abstract

The invention discloses a selenium-containing heat-crack-resistant steel and a processing method thereof, and relates to the technical field of steel. 0.3 wt%-0.5 wt% of selenium is added into the steel, so that the mechanical property of the steel can be improved, the structure is more compact, and the steel has good crack resistance. Zinc is plated on the surface of the steel, and a zinc-plated layer delays corrosion of a base material by isolating oxygen and moisture, so that cracking of a steel matrix caused by corrosion is reduced. The invention also prepares an anticorrosive coating, cerium-containing nano-particles coated with polyethylene glycol are added, glucose is loaded on the cerium-containing nano-particles, and then thiolated polyethylene glycol is coated on the cerium-containing nano-particles. And copper can generate a layer of oxidation film in a glucose contact environment, so that the corrosion inhibition effect is achieved, and the corrosion resistance of the steel is further improved.

Description

Technical Field

[0001] This invention relates to the field of steel technology, specifically to a selenium-containing heat-crack-resistant steel and its processing method. Background Technology

[0002] Steel, as an important industrial material, is widely used in petrochemicals, transportation, construction, and other fields. However, steel is susceptible to corrosion during use, leading to problems such as cracking, reduced strength, and decreased durability. Therefore, developing steel with excellent corrosion resistance and its processing methods has become an important research direction.

[0003] In the steel metallurgical industry, adding metallic elements to steel can produce steel with good crack resistance; for example, sulfur can be added. Adding chromium, nickel, and molybdenum can improve its corrosion resistance. Furthermore, optimizing the internal microstructure of steel through controlled rolling and cooling processes can refine the grains, forming a uniform acicular ferrite and bainite structure, which also effectively improves its corrosion resistance. However, existing technologies still have some shortcomings. For example, the corrosion resistance of some steels in high humidity and strong acid / alkali environments still needs further improvement.

[0004] To address the aforementioned problems and improve the thermal crack resistance and corrosion resistance of steel, this invention provides a selenium-containing thermal crack resistant steel and its processing method. Summary of the Invention

[0005] The purpose of this invention is to provide a selenium-containing heat-crack-resistant steel and its processing method to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for processing selenium-containing, heat-crack-resistant steel includes the following steps:

[0008] Step 1: Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 770-800℃ to obtain steel containing selenium.

[0009] Step 2: Take chromium powder and chromium oxide, mix them evenly, and place them together with the selenium-containing steel in a sealed device, vacuum seal it, heat treat it at 750℃, clean it, and obtain pretreated steel; immerse the pretreated steel in a flux, take it out and dry it to obtain a fluxed steel plate; take the fluxed steel plate, immerse it in the plating solution under nitrogen and hydrogen protection, take it out and cool it to obtain galvanized steel;

[0010] Step 3: Apply anti-corrosion coating evenly to the surface of galvanized steel and cure it to obtain selenium-containing heat-crack resistant steel.

[0011] More preferably, the selenium-containing steel comprises the following components, by weight percentage: 25wt%-29wt% Cr, 6wt%-12wt% Ni, 1wt%-3wt% Mo, 0.7wt%-1.0wt% Si, 0.6wt%-1.2wt% Mn, 0.3wt%-0.5wt% Se, 0.2wt%-0.4wt% N, 0.05wt%-0.1wt% C, 0.01wt%-0.03wt% P, 0.01wt%-0.03wt% S, with the balance being Fe and unavoidable impurities.

[0012] In a more optimized manner, the preparation method of the anti-corrosion coating is as follows: take cerium-containing nanoparticles coated with polyethylene glycol and methyl ethyl ketone, stir evenly, add epoxy curing agent, mix evenly, add branched epoxy resin, acetone and pyrrole, mix evenly to obtain anti-corrosion coating.

[0013] In a more optimized manner, the preparation method of the branched epoxy resin is as follows: hydroquinone, tetrabutylammonium bromide, and 1,1,1,trimethylolpropane triglycidyl ether are heated and reacted for 22-26 hours, then cooled, precipitated, and filtered to obtain the branched epoxy resin.

[0014] In a more optimized manner, the preparation method of the cerium-containing nanoparticles coated with polyethylene glycol is as follows: take mercapto-modified polyethylene glycol and deionized water, stir evenly, add cerium-containing nanoparticles loaded with glucose, stir for 2-3 hours, centrifuge, wash, and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0015] A more optimized method for preparing the glucose-loaded cerium-containing nanoparticles is as follows: take glucose and deionized water, stir evenly, add cerium-containing nanoparticles, stir for 5-6 hours, centrifuge, wash, and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0016] A more optimized method for preparing the cerium-containing nanoparticles is as follows: terephthalic acid, dopamine, and N,N-dimethylformamide are ultrasonically dispersed for 10-20 minutes to obtain a terephthalic acid solution; cerium ammonium nitrate and deionized water are taken, stirred evenly, the terephthalic acid solution is added, stirred evenly, heated to 100℃, heated for 20-25 minutes, centrifuged, washed, and dried to obtain cerium-containing nanoparticles.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. Adding 0.3wt% to 0.5wt% selenium to steel can improve its mechanical properties, make its structure more compact, and give it good crack resistance.

[0019] 2. The present invention galvanizes the surface of steel. The galvanized layer delays the corrosion of the substrate by isolating oxygen and moisture, and reduces cracking of the steel substrate caused by corrosion.

[0020] 3. This invention prepares an anti-corrosion coating by adding cerium-containing nanoparticles coated with polyethylene glycol. Glucose is then loaded onto the cerium-containing nanoparticles, and subsequently coated with thiolated polyethylene glycol. Glucose possesses excellent corrosion inhibition properties and contains numerous polar functional groups such as -OH, which have numerous adsorption sites. The coated thiolated polyethylene glycol absorbs water, swells, and ruptures, releasing glucose. Copper forms an oxide film in the glucose contact environment, thus playing a role in corrosion inhibition.

[0021] 4. This invention uses mercapto-modified polyethylene glycol to coat cerium-containing nanoparticles loaded with glucose. The mercapto groups can combine with metal ions on the surface of galvanized steel, enhancing the corrosion resistance of the anti-corrosion coating and thus improving the corrosion resistance of the steel.

[0022] 5. In the preparation of cerium-containing nanoparticles, dopamine is added to give the surface amino groups, and then a branched epoxy resin is prepared. The cerium-containing nanoparticles coated with polyethylene glycol have good compatibility in the branched epoxy resin, which enhances the corrosion resistance of steel. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The sources and types of substances involved in this invention are not particularly limited, and exemplary ones include: mercapto-modified polyethylene glycol: type: HH0180H7RKMV, which can be purchased from Tengyi Chemical; epoxy curing agent: type: SM2041, which can be purchased from Guodu Chemical; epoxy resin: type: E44, which can be purchased from Hebei Hongda Environmental Protection Technology Co., Ltd.

[0025] Example 1: A processing method for selenium-containing heat-crack-resistant steel, comprising the following steps:

[0026] Step 1: Preparation of selenium-containing steel:

[0027] Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 780℃ to obtain steel containing selenium.

[0028] The selenium-containing steel comprises the following components, by weight percentage: 27 wt% Cr, 8 wt% Ni, 2 wt% Mo, 0.8 wt% Si, 0.9 wt% Mn, 0.4 wt% Se, 0.3 wt% N, 0.07 wt% C, 0.02 wt% P, 0.02 wt% S, with the balance being Fe and unavoidable impurities;

[0029] Step Two: Preparation of Galvanized Steel

[0030] Chromium powder and chromium oxide are mixed evenly and placed together with selenium-containing steel in a sealed device, vacuum sealed, and heat-treated at 750℃ for 280 minutes. After cleaning, pre-treated steel is obtained; the mass ratio of chromium powder to chromium oxide is 0.6:1.

[0031] The pretreated steel was placed in a flux at 73°C for 4 minutes, then removed and dried to obtain a coated steel plate. The coated steel plate was then placed in a plating solution at 458°C for 4 seconds under nitrogen and hydrogen protection, and then cooled to 27°C to obtain galvanized steel.

[0032] The flux uses deionized water as a solvent and includes: 152 g / L ammonium chloride and 152 g / L zinc chloride; the nitrogen content in the protective atmosphere is 5% by volume; the plating solution includes the following components, by weight fraction: 0.2 wt% aluminum, 0.09 wt% lead, and the balance is zinc;

[0033] Step 3: Preparation of cerium-containing nanoparticles coated with polyethylene glycol:

[0034] S1: Preparation of cerium-containing nanoparticles:

[0035] Take 0.4g of terephthalic acid, 3g of dopamine, and 15mL of N,N-dimethylformamide, and ultrasonically disperse for 15min to obtain a terephthalic acid solution; take 2g of cerium ammonium nitrate and 20mL of deionized water, stir evenly, add the terephthalic acid solution, stir evenly, heat to 100℃, heat for 22min, centrifuge, wash, and dry to obtain cerium-containing nanoparticles;

[0036] S2: Take 2g of glucose and 100mL of deionized water, stir well, add 0.5g of cerium-containing nanoparticles, stir for 5.5h, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0037] S3: Take 1.2g of mercapto-modified polyethylene glycol and 100mL of deionized water, stir evenly, add 0.7g of glucose-loaded cerium-containing nanoparticles, stir for 2.5h, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0038] Step 4: Preparation of anti-corrosion coating:

[0039] S1: Preparation of branched epoxy resin:

[0040] Take 55g hydroquinone, 8g tetrabutylammonium bromide, and 213g 1,1,1,trimethylolpropane triglycidyl ether, heat the reaction for 23h, cool, precipitate, and filter to obtain branched epoxy resin.

[0041] S2: Take 8g of cerium-containing nanoparticles coated with polyethylene glycol and 10mL of butanone, stir evenly, add 35g of epoxy curing agent, mix evenly, add 75g of branched epoxy resin, 22g of acetone and 12g of pyrrole, mix evenly to obtain anti-corrosion coating.

[0042] Step 5: Preparation of selenium-containing hot-cracking resistant steel:

[0043] A 100μm thick anti-corrosion coating is uniformly applied to the surface of galvanized steel and cured to obtain selenium-containing heat-crack resistant steel.

[0044] Example 2: A processing method for selenium-containing heat-crack-resistant steel, comprising the following steps:

[0045] Step 1: Preparation of selenium-containing steel:

[0046] Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 770℃ to obtain steel containing selenium.

[0047] The selenium-containing steel comprises the following components, by weight percentage: 25 wt% Cr, 6 wt% Ni, 1 wt% Mo, 0.7 wt% Si, 0.6 wt% Mn, 0.3 wt% Se, 0.2 wt% N, 0.05 wt% C, 0.01 wt% P, 0.01 wt% S, with the balance being Fe and unavoidable impurities;

[0048] Step Two: Preparation of Galvanized Steel

[0049] Chromium powder and chromium oxide are mixed evenly and placed together with selenium-containing steel in a sealed device, vacuum sealed, and heat-treated at 750℃ for 250 minutes. After cleaning, pre-treated steel is obtained; the mass ratio of chromium powder to chromium oxide is 0.6:1.

[0050] The pretreated steel is placed in a flux at 70°C for 3 minutes, then removed and dried to obtain a coated steel plate. The coated steel plate is then placed in a plating solution at 455°C for 3 seconds under nitrogen and hydrogen protection, and then cooled to 25°C to obtain galvanized steel.

[0051] The flux uses deionized water as a solvent and includes: 152 g / L ammonium chloride and 152 g / L zinc chloride; the nitrogen content in the protective atmosphere is 5% by volume; the plating solution includes the following components, by weight fraction: 0.2 wt% aluminum, 0.09 wt% lead, and the balance is zinc;

[0052] Step 3: Preparation of cerium-containing nanoparticles coated with polyethylene glycol:

[0053] S1: Preparation of cerium-containing nanoparticles:

[0054] Take 0.4g of terephthalic acid, 3g of dopamine, and 15mL of N,N-dimethylformamide, and ultrasonically disperse for 10min to obtain a terephthalic acid solution; take 2g of cerium ammonium nitrate and 20mL of deionized water, stir evenly, add the terephthalic acid solution, stir evenly, heat to 100℃, heat for 20min, centrifuge, wash, and dry to obtain cerium-containing nanoparticles;

[0055] S2: Take 2g of glucose and 100mL of deionized water, stir well, add 0.5g of cerium-containing nanoparticles, stir for 5h, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0056] S3: Take 1.2g of mercapto-modified polyethylene glycol and 100mL of deionized water, stir evenly, add 0.7g of glucose-loaded cerium-containing nanoparticles, stir for 2h, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0057] Step 4: Preparation of anti-corrosion coating:

[0058] S1: Preparation of branched epoxy resin:

[0059] Take 55g hydroquinone, 8g tetrabutylammonium bromide, and 213g 1,1,1,trimethylolpropane triglycidyl ether, heat and react for 22h, cool, precipitate, and filter to obtain branched epoxy resin.

[0060] S2: Take 8g of cerium-containing nanoparticles coated with polyethylene glycol and 10mL of butanone, stir evenly, add 35g of epoxy curing agent, mix evenly, add 75g of branched epoxy resin, 22g of acetone and 12g of pyrrole, mix evenly to obtain anti-corrosion coating.

[0061] Step 5: Preparation of selenium-containing hot-cracking resistant steel:

[0062] A 100μm thick anti-corrosion coating is uniformly applied to the surface of galvanized steel and cured to obtain selenium-containing heat-crack resistant steel.

[0063] Example 3: A processing method for selenium-containing heat-crack-resistant steel, comprising the following steps:

[0064] Step 1: Preparation of selenium-containing steel:

[0065] Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 800℃ to obtain steel containing selenium.

[0066] The selenium-containing steel comprises the following components, by weight percentage: 29 wt% Cr, 12 wt% Ni, 3 wt% Mo, 1.0 wt% Si, 1.2 wt% Mn, 0.5 wt% Se, 0.4 wt% N, 0.1 wt% C, 0.03 wt% P, 0.03 wt% S, with the balance being Fe and unavoidable impurities;

[0067] Step Two: Preparation of Galvanized Steel

[0068] Chromium powder and chromium oxide are mixed evenly and placed together with selenium-containing steel in a sealed device, vacuum sealed, and heat-treated at 750℃ for 300 minutes. After cleaning, pre-treated steel is obtained; the mass ratio of chromium powder to chromium oxide is 0.6:1.

[0069] The pretreated steel is placed in a flux at 75°C for 5 minutes, then removed and dried to obtain a coated steel plate. The coated steel plate is then placed in a plating solution at 460°C for 5 seconds under nitrogen and hydrogen protection, and then cooled to 30°C to obtain galvanized steel.

[0070] The flux uses deionized water as a solvent and includes: 152 g / L ammonium chloride and 152 g / L zinc chloride; the nitrogen content in the protective atmosphere is 5% by volume; the plating solution includes the following components, by weight fraction: 0.2 wt% aluminum, 0.09 wt% lead, and the balance is zinc;

[0071] Step 3: Preparation of cerium-containing nanoparticles coated with polyethylene glycol:

[0072] S1: Preparation of cerium-containing nanoparticles:

[0073] Take 0.4g of terephthalic acid, 3g of dopamine, and 15mL of N,N-dimethylformamide, and ultrasonically disperse for 20min to obtain a terephthalic acid solution; take 2g of cerium ammonium nitrate and 20mL of deionized water, stir evenly, add the terephthalic acid solution, stir evenly, heat to 100℃, heat for 25min, centrifuge, wash, and dry to obtain cerium-containing nanoparticles;

[0074] S2: Take 2g of glucose and 100mL of deionized water, stir well, add 0.5g of cerium-containing nanoparticles, stir for 6h, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0075] S3: Take 1.2g of mercapto-modified polyethylene glycol and 100mL of deionized water, stir evenly, add 0.7g of glucose-loaded cerium-containing nanoparticles, stir for 3h, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0076] Step 4: Preparation of anti-corrosion coating:

[0077] S1: Preparation of branched epoxy resin:

[0078] Take 55g hydroquinone, 8g tetrabutylammonium bromide, and 213g 1,1,1,trimethylolpropane triglycidyl ether, heat and react for 26h, cool, precipitate, and filter to obtain branched epoxy resin.

[0079] S2: Take 8g of cerium-containing nanoparticles coated with polyethylene glycol and 10mL of butanone, stir evenly, add 35g of epoxy curing agent, mix evenly, add 75g of branched epoxy resin, 22g of acetone and 12g of pyrrole, mix evenly to obtain anti-corrosion coating.

[0080] Step 5: Preparation of selenium-containing hot-cracking resistant steel:

[0081] A 100μm thick anti-corrosion coating is uniformly applied to the surface of galvanized steel and cured to obtain selenium-containing heat-crack resistant steel.

[0082] Comparative Example 1: Dopamine was not added to the cerium-containing nanoparticles; all other aspects were the same as in Example 1.

[0083] Step 1: Preparation of selenium-containing steel:

[0084] Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 780℃ to obtain steel containing selenium.

[0085] The selenium-containing steel comprises the following components, by weight percentage: 27 wt% Cr, 8 wt% Ni, 2 wt% Mo, 0.8 wt% Si, 0.9 wt% Mn, 0.4 wt% Se, 0.3 wt% N, 0.07 wt% C, 0.02 wt% P, 0.02 wt% S, with the balance being Fe and unavoidable impurities;

[0086] Step Two: Preparation of Galvanized Steel

[0087] Chromium powder and chromium oxide are mixed evenly and placed together with selenium-containing steel in a sealed device, vacuum sealed, and heat-treated at 750℃ for 280 minutes. After cleaning, pre-treated steel is obtained; the mass ratio of chromium powder to chromium oxide is 0.6:1.

[0088] The pretreated steel was placed in a flux at 73°C for 4 minutes, then removed and dried to obtain a coated steel plate. The coated steel plate was then placed in a plating solution at 458°C for 4 seconds under nitrogen and hydrogen protection, and then cooled to 27°C to obtain galvanized steel.

[0089] The flux uses deionized water as a solvent and includes: 152 g / L ammonium chloride and 152 g / L zinc chloride; the nitrogen content in the protective atmosphere is 5% by volume; the plating solution includes the following components, by weight fraction: 0.2 wt% aluminum, 0.09 wt% lead, and the balance is zinc;

[0090] Step 3: Preparation of cerium-containing nanoparticles coated with polyethylene glycol:

[0091] S1: Preparation of cerium-containing nanoparticles:

[0092] Take 0.4g of terephthalic acid and 15mL of N,N-dimethylformamide, and ultrasonically disperse for 15min to obtain a terephthalic acid solution; take 2g of cerium ammonium nitrate and 20mL of deionized water, stir evenly, add the terephthalic acid solution, stir evenly, heat to 100℃, heat for 22min, centrifuge, wash, and dry to obtain cerium-containing nanoparticles;

[0093] S2: Take 2g of glucose and 100mL of deionized water, stir well, add 0.5g of cerium-containing nanoparticles, stir for 5.5h, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0094] S3: Take 1.2g of mercapto-modified polyethylene glycol and 100mL of deionized water, stir evenly, add 0.7g of glucose-loaded cerium-containing nanoparticles, stir for 2.5h, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0095] Step 4: Preparation of anti-corrosion coating:

[0096] S1: Preparation of branched epoxy resin:

[0097] Take 55g hydroquinone, 8g tetrabutylammonium bromide, and 213g 1,1,1,trimethylolpropane triglycidyl ether, heat the reaction for 23h, cool, precipitate, and filter to obtain branched epoxy resin.

[0098] S2: Take 8g of cerium-containing nanoparticles coated with polyethylene glycol and 10mL of butanone, stir evenly, add 35g of epoxy curing agent, mix evenly, add 75g of branched epoxy resin, 22g of acetone and 12g of pyrrole, mix evenly to obtain anti-corrosion coating.

[0099] Step 5: Preparation of selenium-containing hot-cracking resistant steel:

[0100] A 100μm thick anti-corrosion coating is uniformly applied to the surface of galvanized steel and cured to obtain selenium-containing heat-crack resistant steel.

[0101] Comparative Example 2: Polyethylene glycol was used instead of thiolated polyethylene glycol, and the rest was the same as in Example 1:

[0102] Step 1: Preparation of selenium-containing steel:

[0103] Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 780℃ to obtain steel containing selenium.

[0104] The selenium-containing steel comprises the following components, by weight percentage: 27 wt% Cr, 8 wt% Ni, 2 wt% Mo, 0.8 wt% Si, 0.9 wt% Mn, 0.4 wt% Se, 0.3 wt% N, 0.07 wt% C, 0.02 wt% P, 0.02 wt% S, with the balance being Fe and unavoidable impurities;

[0105] Step Two: Preparation of Galvanized Steel

[0106] Chromium powder and chromium oxide are mixed evenly and placed together with selenium-containing steel in a sealed device, vacuum sealed, and heat-treated at 750℃ for 280 minutes. After cleaning, pre-treated steel is obtained; the mass ratio of chromium powder to chromium oxide is 0.6:1.

[0107] The pretreated steel was placed in a flux at 73°C for 4 minutes, then removed and dried to obtain a coated steel plate. The coated steel plate was then placed in a plating solution at 458°C for 4 seconds under nitrogen and hydrogen protection, and then cooled to 27°C to obtain galvanized steel.

[0108] The flux uses deionized water as a solvent and includes: 152 g / L ammonium chloride and 152 g / L zinc chloride; the nitrogen content in the protective atmosphere is 5% by volume; the plating solution includes the following components, by weight fraction: 0.2 wt% aluminum, 0.09 wt% lead, and the balance is zinc;

[0109] Step 3: Preparation of cerium-containing nanoparticles coated with polyethylene glycol:

[0110] S1: Preparation of cerium-containing nanoparticles:

[0111] Take 0.4g of terephthalic acid, 3g of dopamine, and 15mL of N,N-dimethylformamide, and ultrasonically disperse for 15min to obtain a terephthalic acid solution; take 2g of cerium ammonium nitrate and 20mL of deionized water, stir evenly, add the terephthalic acid solution, stir evenly, heat to 100℃, heat for 22min, centrifuge, wash, and dry to obtain cerium-containing nanoparticles;

[0112] S2: Take 2g of glucose and 100mL of deionized water, stir well, add 0.5g of cerium-containing nanoparticles, stir for 5.5h, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0113] S3: Take 1.2g polyethylene glycol and 100mL deionized water, stir evenly, add 0.7g glucose-loaded cerium-containing nanoparticles, stir for 2.5h, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0114] Step 4: Preparation of anti-corrosion coating:

[0115] S1: Preparation of branched epoxy resin:

[0116] Take 55g hydroquinone, 8g tetrabutylammonium bromide, and 213g 1,1,1,trimethylolpropane triglycidyl ether, heat the reaction for 23h, cool, precipitate, and filter to obtain branched epoxy resin.

[0117] S2: Take 8g of cerium-containing nanoparticles coated with polyethylene glycol and 10mL of butanone, stir evenly, add 35g of epoxy curing agent, mix evenly, add 75g of branched epoxy resin, 22g of acetone and 12g of pyrrole, mix evenly to obtain anti-corrosion coating.

[0118] Step 5: Preparation of selenium-containing hot-cracking resistant steel:

[0119] A 100μm thick anti-corrosion coating is uniformly applied to the surface of galvanized steel and cured to obtain selenium-containing heat-crack resistant steel.

[0120] Comparative Example 3: Epoxy resin was used instead of branched epoxy resin, and the rest was the same as in Example 1:

[0121] Step 1: Preparation of selenium-containing steel:

[0122] Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 780℃ to obtain steel containing selenium.

[0123] The selenium-containing steel comprises the following components, by weight percentage: 27 wt% Cr, 8 wt% Ni, 2 wt% Mo, 0.8 wt% Si, 0.9 wt% Mn, 0.4 wt% Se, 0.3 wt% N, 0.07 wt% C, 0.02 wt% P, 0.02 wt% S, with the balance being Fe and unavoidable impurities;

[0124] Step Two: Preparation of Galvanized Steel

[0125] Chromium powder and chromium oxide are mixed evenly and placed together with selenium-containing steel in a sealed device, vacuum sealed, and heat-treated at 750℃ for 280 minutes. After cleaning, pre-treated steel is obtained; the mass ratio of chromium powder to chromium oxide is 0.6:1.

[0126] The pretreated steel was placed in a flux at 73°C for 4 minutes, then removed and dried to obtain a coated steel plate. The coated steel plate was then placed in a plating solution at 458°C for 4 seconds under nitrogen and hydrogen protection, and then cooled to 27°C to obtain galvanized steel.

[0127] The flux uses deionized water as a solvent and includes: 152 g / L ammonium chloride and 152 g / L zinc chloride; the nitrogen content in the protective atmosphere is 5% by volume; the plating solution includes the following components, by weight fraction: 0.2 wt% aluminum, 0.09 wt% lead, and the balance is zinc;

[0128] Step 3: Preparation of cerium-containing nanoparticles coated with polyethylene glycol:

[0129] S1: Preparation of cerium-containing nanoparticles:

[0130] Take 0.4g of terephthalic acid, 3g of dopamine, and 15mL of N,N-dimethylformamide, and ultrasonically disperse for 15min to obtain a terephthalic acid solution; take 2g of cerium ammonium nitrate and 20mL of deionized water, stir evenly, add the terephthalic acid solution, stir evenly, heat to 100℃, heat for 22min, centrifuge, wash, and dry to obtain cerium-containing nanoparticles;

[0131] S2: Take 2g of glucose and 100mL of deionized water, stir well, add 0.5g of cerium-containing nanoparticles, stir for 5.5h, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

[0132] S3: Take 1.2g of mercapto-modified polyethylene glycol and 100mL of deionized water, stir evenly, add 0.7g of glucose-loaded cerium-containing nanoparticles, stir for 2.5h, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

[0133] Step 4: Preparation of anti-corrosion coating:

[0134] Take 8g of cerium-containing nanoparticles coated with polyethylene glycol and 10mL of butanone, stir evenly, add 35g of epoxy curing agent, mix evenly, add 75g of epoxy resin, 22g of acetone and 12g of pyrrole, mix evenly to obtain the anti-corrosion coating.

[0135] Step 5: Preparation of selenium-containing hot-cracking resistant steel:

[0136] A 100μm thick anti-corrosion coating is uniformly applied to the surface of galvanized steel and cured to obtain selenium-containing heat-crack resistant steel.

[0137] experiment:

[0138] The selenium-containing hot-crack resistant steels prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. The tensile strength of the hot-crack resistant steels was tested using an electro-hydraulic servo dynamic fatigue testing machine. Following the ASTM-D1654 scratch test standard, uniform "X" shaped marks were made on the surface of the selenium-containing hot-crack resistant steels prepared in the examples and comparative examples. The scratched samples were then immersed in a 3.5 wt% sodium chloride solution for several hours, and then removed to observe the corrosion morphology at the scratches. The data obtained are shown in Table 1 below.

[0139] Table 1

[0140]

[0141] Conclusion: The data comparison in the table shows that in Comparative Example 1, without the addition of dopamine to the cerium-containing nanoparticles, the corrosion resistance deteriorated. After immersion in sodium chloride solution for 1500 hours, corrosion appeared at the scratches, and the coating peeled off. In Comparative Example 2, using polyethylene glycol instead of thiol-modified polyethylene glycol resulted in poor glucose release, and the thiol groups could not effectively bind with metal ions on the galvanized steel surface, leading to a decrease in the steel's corrosion resistance. In Comparative Example 3, using epoxy resin instead of branched epoxy resin reduced the number of active sites. After 1440 hours, the compatibility of the cerium-containing nanoparticles coated with polyethylene glycol in the branched epoxy resin deteriorated, resulting in corrosion at the scratches and coating peeling off. The selenium-containing, hot-crack-resistant steel prepared in Examples 1-3 of this invention exhibits good tensile strength, reaching 1545 MPa. In Examples 1-3 of this invention, galvanizing the steel surface, the zinc plating layer, by isolating oxygen and moisture, delays substrate corrosion and reduces cracking of the steel matrix caused by corrosion. Thiol-modified polyethylene glycol was used to coat cerium-containing nanoparticles loaded with glucose. The thiol groups can combine with metal ions on the surface of galvanized steel, enhancing the corrosion resistance of the anti-corrosion coating and thus improving the corrosion resistance of the steel. In Examples 1-3 of this invention, dopamine was added to the surface of the cerium-containing nanoparticles to give them amino groups. Then, a branched epoxy resin was prepared. The cerium-containing nanoparticles coated with polyethylene glycol showed good compatibility in the branched epoxy resin, enhancing the corrosion resistance of the steel. Therefore, after the steel was immersed in sodium chloride solution for 15-12 hours, there was no corrosion at the scratches, the coating remained intact, and the corrosion resistance was good.

[0142] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for processing selenium-containing, heat-crack-resistant steel, characterized in that: Includes the following steps: Step 1: Take Fe, Cr, Ni, Mo, Si, Mn, Se, N, C, P, and S, and melt, roll, cast, and demold at 770-800℃ to obtain steel containing selenium. Step 2: Take chromium powder and chromium oxide, mix them evenly, and place them together with the steel containing selenium in a sealed device, vacuum seal it, heat treat it at 750℃, clean it, and obtain the pretreated steel. The pretreated steel is immersed in a flux, removed and dried to obtain a fluxed steel sheet; the fluxed steel sheet is then immersed in a plating solution under nitrogen and hydrogen protection, removed and cooled to obtain galvanized steel. Step 3: Apply anti-corrosion coating evenly to the surface of galvanized steel and cure it to obtain selenium-containing heat-crack resistant steel.

2. The processing method of a selenium-containing, heat-crack-resistant steel according to claim 1, characterized in that: The selenium-containing steel comprises the following components, by weight percentage: 25wt%-29wt% Cr, 6wt%-12wt% Ni, 1wt%-3wt% Mo, 0.7wt%-1.0wt% Si, 0.6wt%-1.2wt% Mn, 0.3wt%-0.5wt% Se, 0.2wt%-0.4wt% N, 0.05wt%-0.1wt% C, 0.01wt%-0.03wt% P, 0.01wt%-0.03wt% S, with the balance being Fe and unavoidable impurities.

3. The processing method of a selenium-containing, heat-crack-resistant steel according to claim 1, characterized in that: The method for preparing the anti-corrosion coating is as follows: take cerium-containing nanoparticles coated with polyethylene glycol and methyl ethyl ketone, stir evenly, add epoxy curing agent, mix evenly, add branched epoxy resin, acetone and pyrrole, mix evenly to obtain the anti-corrosion coating.

4. The processing method of a selenium-containing, heat-crack-resistant steel according to claim 3, characterized in that: The preparation method of the branched epoxy resin is as follows: take hydroquinone, tetrabutylammonium bromide, and 1,1,1,trimethylolpropane triglycidyl ether, heat and react for 22-26 hours, cool, precipitate, and filter to obtain the branched epoxy resin.

5. The processing method of a selenium-containing heat-crack-resistant steel according to claim 3, characterized in that: The method for preparing the cerium-containing nanoparticles coated with polyethylene glycol is as follows: take mercapto-modified polyethylene glycol and deionized water, stir evenly, add cerium-containing nanoparticles loaded with glucose, stir for 2-3 hours, centrifuge, wash and dry to obtain cerium-containing nanoparticles coated with polyethylene glycol.

6. The processing method of a selenium-containing, heat-crack-resistant steel according to claim 5, characterized in that: The method for preparing glucose-loaded cerium-containing nanoparticles is as follows: take glucose and deionized water, stir evenly, add cerium-containing nanoparticles, stir for 5-6 hours, centrifuge, wash and dry to obtain glucose-loaded cerium-containing nanoparticles.

7. The processing method of a selenium-containing, heat-crack-resistant steel according to claim 6, characterized in that: The method for preparing the cerium-containing nanoparticles is as follows: terephthalic acid, dopamine, and N,N-dimethylformamide are ultrasonically dispersed for 10-20 min to obtain a terephthalic acid solution; cerium ammonium nitrate and deionized water are taken, stirred evenly, the terephthalic acid solution is added, stirred evenly, heated to 100℃, heated for 20-25 min, centrifuged, washed, and dried to obtain cerium-containing nanoparticles.

8. The selenium-containing heat-crack-resistant steel obtained by the processing method of the selenium-containing heat-crack-resistant steel according to claims 1-7.

Images