High-strength rare earth weathering steel and preparation process thereof

Abstract

The invention discloses high-strength rare earth weathering resistant steel and a preparation process thereof, and relates to the technical field of weathering resistant steel. The rare earth elements lanthanum and cerium are added into the weathering resistant steel as raw materials, grain refinement of a weathering resistant steel matrix can be effectively promoted, the microstructure and performance of the weathering resistant steel are improved, and the weathering resistance and strength of the steel are improved. The polysilsesquioxane sol A and the polysilsesquioxane sol B are prepared, and rare earth salt lanthanum chloride is added, so that the compactness of the coating is enhanced, and the corrosion resistance and weather resistance of the rare earth weathering resistant steel are improved. The polysilsesquioxane sol A and the polysilsesquioxane sol B are compounded, so that a corrosion-resistant coating on the surface of the weathering steel is more compact, and the corrosion resistance of the weathering steel is improved.

Description

Technical Field

[0001] The invention relates to the technical field of weathering steel, in particular to a high-strength rare earth weathering steel and a preparation process thereof. Background Art

[0002] With the development of the manufacturing industry, the corrosion resistance, weather resistance and mechanical properties of steel are becoming increasingly important. Rare earth elements are added to steel as raw materials, which can effectively promote the grain refinement of the steel matrix and improve the microstructure and performance of the steel, especially in terms of corrosion resistance, high temperature resistance and increased strength. Weathering steel is widely used in structures such as bridges, buildings, and ships, but its corrosion resistance still has room for further improvement in environments containing corrosive substances. With the advancement of science and technology and the needs of industrial applications, the development of a high-strength rare earth weathering steel that can not only meet the use requirements in complex environments, but also effectively extend the service life of steel has become an important research direction in the steel industry.

[0003] In order to solve the above problems and improve the corrosion resistance of steel, the present invention provides a high-strength rare earth weathering steel and a preparation process thereof. Summary of the invention

[0004] The object of the present invention is to provide a high-strength rare earth weathering steel and a preparation process thereof, so as to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A preparation process of high-strength rare earth weathering steel comprises the following steps:

[0007] Step 1: Take silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum, and cerium, smelt and cast to obtain steel ingots, heat to 1200-1220℃ and keep warm for 3-4h, roll, cool and wash to obtain rare earth weathering steel;

[0008] Step 2: Take nickel-plated carbon nanotubes, glycidyloxypropyltrimethoxysilane, and ethanol, heat to 70-75° C., react for 50-70 minutes, then dropwise add a mixture of ethyl orthosilicate, lanthanum chloride, methyltriethoxysilane, ethanol, and deionized water, react at 70-75° C. for 50-70 minutes to obtain polysilsesquioxane sol A;

[0009] Take carbon nanotubes, glycidyloxypropyltrimethoxysilane and ethanol, raise the temperature to 70-75°C, react for 50-70 minutes, then drop a mixture of ethyl orthosilicate, lanthanum chloride, methyltriethoxysilane, ethanol and deionized water, react at 70-75°C for 50-70 minutes to obtain polysilsesquioxane sol B;

[0010] Step 3: spray polysilsesquioxane sol B on the surface of rare earth weathering steel, dry it, and then spray polysilsesquioxane sol A on the surface of polysilsesquioxane sol B, dry it, and obtain high-strength rare earth weathering steel.

[0011] More optimally, when the polysilsesquioxane sol A is dried, it is in a horizontal magnetic field with a magnetic field strength of 0.5T-0.6T.

[0012] More optimally, the rare earth weathering steel consists of the following components: in mass fraction, 0.20wt%-0.25wt% silicon, 0.05wt%-0.06wt% carbon, 0.55wt%-1.0wt% manganese, 0.55wt%-0.60wt% chromium, 0.45wt%-0.55wt% copper, 0.25wt%-0.35wt% nickel, 0.0011wt%-0.0012wt% calcium, 0.013wt%-0.016wt% titanium, 0.001wt%-0.012wt% phosphorus, 0.001wt%-0.002wt% sulfur, 0.0004wt%-0.006wt% lanthanum, and 0.0003wt%-0.005wt% cerium.

[0013] More optimally, the method for preparing the nickel-plated carbon nanotubes is: adding the treated carbon nanotubes into a nickel plating solution, reacting at 35-40° C. for 30-40 minutes, taking out, washing, and drying to obtain the nickel-plated carbon nanotubes.

[0014] More optimally, the nickel plating solution includes the following ingredients: nickel chloride hexahydrate, nickel sulfate hexahydrate, ammonium chloride, sodium citrate, sodium hypophosphite, lead nitrate, phytic acid, and deionized water as solvent.

[0015] More optimally, the preparation method of the treated carbon nanotubes is: take carbon nanotubes and concentrated nitric acid solution, oscillate at 75-80°C for 7-9h, add deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take the acidified carbon nanotubes, add deionized water, ultrasonically disperse, add dihydrate stannous chloride sensitizer and hydrochloric acid, and oscillate for 15-20min; filter, wash, dry, add 100mL deionized water, ultrasonically disperse, add palladium dichloride and hydrochloric acid, oscillate for 15-20min, filter, wash, and dry to obtain treated carbon nanotubes.

[0016] More optimally, the magnetic field strength is 0.5T.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention adds rare earth elements lanthanum and cerium as raw materials to weathering steel, which can effectively promote the grain refinement of the weathering steel matrix, improve the microstructure and performance of the weathering steel, and enhance the weather resistance and strength of the steel.

[0019] 2. The present invention prepares polysilsesquioxane sol A and polysilsesquioxane sol B, and by adding rare earth salt lanthanum chloride, the density of the coating is enhanced, thereby improving the corrosion resistance and weather resistance of rare earth weathering steel. The compounding of polysilsesquioxane sol A and polysilsesquioxane sol B makes the corrosion-resistant coating on the surface of the weathering steel more dense, thereby improving the corrosion resistance of the weathering steel.

[0020] 3. Nickel-plated carbon nanotubes are added to polysilsesquioxane sol A, and a layer of nickel is plated on the carbon nanotubes using a nickel plating solution. Nickel is a metal with ferromagnetism. A layer of nickel is plated on the carbon nanotubes, so that a dense oxide protective layer is formed on the surface of the carbon nanotubes, which hinders the invasion of corrosive media and improves the corrosion resistance of the coating. The present invention also adds phytic acid to the nickel plating solution, and the addition of phytic acid further enhances the corrosion resistance of the carbon nanotubes. Plating a layer of nickel on the carbon nanotubes also makes the carbon nanotubes magnetic, and under the action of a magnetic field, they can be better dispersed, thereby improving the corrosion resistance of rare earth weathering steel. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The sources of the substances involved in the present invention are not particularly limited, and illustratively include: carbon nanotubes: diameter: 10-100 nm, length: 1-50 μm, which can be purchased from Shenzhen Nanoport Co., Ltd.

[0023] Embodiment 1: A process for preparing high-strength rare earth weathering steel, comprising the following steps:

[0024] Step 1: Preparation of rare earth weathering steel:

[0025] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1210°C and kept warm for 3.5 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0026] The rare earth weathering steel is composed of the following components: by mass fraction, 0.22wt% silicon, 0.055wt% carbon, 0.8wt% manganese, 0.58wt% chromium, 0.50wt% copper, 0.30wt% nickel, 0.0011wt% calcium, 0.015wt% titanium, 0.0011wt% phosphorus, 0.0015wt% sulfur, 0.0005wt% lanthanum, and 0.0004wt% cerium;

[0027] Step 2: Preparation of nickel-plated carbon nanotubes:

[0028] Take 5g of carbon nanotubes and 150mL of concentrated nitric acid solution, shake at 77°C for 8h, add 150mL of deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take 0.1g of acidified carbon nanotubes, add 100mL of deionized water, ultrasonically disperse, add 1g of dihydrate stannous chloride sensitizer and 4g of hydrochloric acid, and shake for 18min; filter, wash, dry, add 100mL of deionized water, ultrasonically disperse, add 0.04g of palladium dichloride and 1g of hydrochloric acid, shake for 18min, filter, wash, and dry to obtain treated carbon nanotubes; add the treated carbon nanotubes to a nickel plating solution, react at 35°C for 30min, take out, wash, and dry to obtain nickel-plated carbon nanotubes;

[0029] The nickel plating solution includes the following ingredients: 0.2 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, 1.6 mol / L ammonium chloride, 0.1 mol / L sodium citrate, 0.6 mol / L sodium hypophosphite, 0.004 mol / L lead nitrate, 0.005 mol / L phytic acid, with deionized water as solvent;

[0030] Step 3:

[0031] Preparation of polysilsesquioxane sol A:

[0032] Take 0.2g nickel-plated carbon nanotubes, 0.9g glycidyloxypropyltrimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 73°C for 60min to obtain polysilsesquioxane sol A;

[0033] Preparation of polysilsesquioxane sol B:

[0034] Take 0.2g carbon nanotubes, 0.9g glycidyloxypropyl trimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 72°C for 60min to obtain polysilsesquioxane sol B;

[0035] Step 4: Preparation of high-strength rare earth weathering steel:

[0036] Polysilsesquioxane sol B is sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm and dried at 25°C for 1 hour. Polysilsesquioxane sol A is then sprayed on the surface of polysilsesquioxane sol B with a spraying thickness of 3 μm and dried at 25°C in a horizontal magnetic field for 1 hour with a magnetic field intensity of 0.5 T to obtain high-strength rare earth weathering steel.

[0037] Embodiment 2: A process for preparing high-strength rare earth weathering steel, comprising the following steps:

[0038] Step 1: Preparation of rare earth weathering steel:

[0039] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1200°C and kept warm for 3 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0040] The rare earth weathering steel is composed of the following components: by mass fraction, 0.20wt% silicon, 0.05wt% carbon, 0.55wt% manganese, 0.55wt% chromium, 0.45wt% copper, 0.25wt% nickel, 0.0011wt% calcium, 0.013wt% titanium, 0.001wt% phosphorus, 0.001wt% sulfur, 0.0004wt% lanthanum, and 0.0003wt% cerium;

[0041] Step 2: Preparation of nickel-plated carbon nanotubes:

[0042] Take 5g of carbon nanotubes and 150mL of concentrated nitric acid solution, shake at 75°C for 7h, add 150mL of deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take 0.1g of acidified carbon nanotubes, add 100mL of deionized water, ultrasonically disperse, add 1g of dihydrate stannous chloride sensitizer and 4g of hydrochloric acid, and shake for 15min; filter, wash, dry, add 100mL of deionized water, ultrasonically disperse, add 0.04g of palladium dichloride and 1g of hydrochloric acid, shake for 15min, filter, wash, and dry to obtain treated carbon nanotubes; add the treated carbon nanotubes to a nickel plating solution, react at 35°C for 30min, take out, wash, and dry to obtain nickel-plated carbon nanotubes;

[0043] The nickel plating solution includes the following ingredients: 0.2 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, 1.6 mol / L ammonium chloride, 0.1 mol / L sodium citrate, 0.6 mol / L sodium hypophosphite, 0.004 mol / L lead nitrate, 0.005 mol / L phytic acid, with deionized water as solvent;

[0044] Step 3:

[0045] Preparation of polysilsesquioxane sol A:

[0046] 0.2 g of nickel-plated carbon nanotubes, 0.9 g of glycidyloxypropyltrimethoxysilane, and 40 mL of ethanol were taken, heated to 70° C., and reacted for 50 min. Then, a mixed solution of 4 g of ethyl orthosilicate, 0.8 g of lanthanum chloride, 70 g of methyltriethoxysilane, 20 mL of ethanol, and 20 mL of deionized water was added dropwise, and reacted at 70° C. for 50 min to obtain polysilsesquioxane sol A;

[0047] Preparation of polysilsesquioxane sol B:

[0048] Take 0.2g carbon nanotubes, 0.9g glycidyloxypropyl trimethoxysilane, and 40mL ethanol, heat to 70°C, react for 50min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 70°C for 50min to obtain polysilsesquioxane sol B;

[0049] Step 4: Preparation of high-strength rare earth weathering steel:

[0050] Polysilsesquioxane sol B is sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm and dried at 25°C for 1 hour. Polysilsesquioxane sol A is then sprayed on the surface of polysilsesquioxane sol B with a spraying thickness of 3 μm and dried at 25°C in a horizontal magnetic field for 1 hour with a magnetic field intensity of 0.5 T to obtain high-strength rare earth weathering steel.

[0051] Embodiment 3: A process for preparing high-strength rare earth weathering steel, comprising the following steps:

[0052] Step 1: Preparation of rare earth weathering steel:

[0053] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1220°C and kept for 4 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0054] The rare earth weathering steel is composed of the following components: by mass fraction, 0.25wt% silicon, 0.06wt% carbon, 1.0wt% manganese, 0.60wt% chromium, 0.55wt% copper, 0.35wt% nickel, 0.0012wt% calcium, 0.016wt% titanium, 0.012wt% phosphorus, 0.002wt% sulfur, 0.006wt% lanthanum, and 0.005wt% cerium;

[0055] Step 2: Preparation of nickel-plated carbon nanotubes:

[0056] Take 5g of carbon nanotubes and 150mL of concentrated nitric acid solution, shake at 80°C for 9h, add 150mL of deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take 0.1g of acidified carbon nanotubes, add 100mL of deionized water, ultrasonically disperse, add 1g of dihydrate stannous chloride sensitizer and 4g of hydrochloric acid, and shake for 20min; filter, wash, dry, add 100mL of deionized water, ultrasonically disperse, add 0.04g of palladium dichloride and 1g of hydrochloric acid, shake for 20min, filter, wash, and dry to obtain treated carbon nanotubes; add the treated carbon nanotubes to a nickel plating solution, react at 35°C for 30min, take out, wash, and dry to obtain nickel-plated carbon nanotubes;

[0057] The nickel plating solution includes the following ingredients: 0.2 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, 1.6 mol / L ammonium chloride, 0.1 mol / L sodium citrate, 0.6 mol / L sodium hypophosphite, 0.004 mol / L lead nitrate, 0.005 mol / L phytic acid, with deionized water as solvent;

[0058] Step 3:

[0059] Preparation of polysilsesquioxane sol A:

[0060] Take 0.2g nickel-plated carbon nanotubes, 0.9g glycidyloxypropyltrimethoxysilane, and 40mL ethanol, heat to 75°C, react for 70min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 75°C for 70min to obtain polysilsesquioxane sol A;

[0061] Preparation of polysilsesquioxane sol B:

[0062] Take 0.2g carbon nanotubes, 0.9g glycidyloxypropyl trimethoxysilane, and 40mL ethanol, heat to 75°C, react for 70min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 75°C for 70min to obtain polysilsesquioxane sol B;

[0063] Step 4: Preparation of high-strength rare earth weathering steel:

[0064] Polysilsesquioxane sol B is sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm and dried at 25°C for 1 hour. Polysilsesquioxane sol A is then sprayed on the surface of polysilsesquioxane sol B with a spraying thickness of 3 μm and dried at 25°C in a horizontal magnetic field for 1 hour with a magnetic field intensity of 0.5 T to obtain high-strength rare earth weathering steel.

[0065] Comparative Example 1: Lanthanum chloride is not added, and the rest is the same as Example 1:

[0066] Step 1: Preparation of rare earth weathering steel:

[0067] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1210°C and kept warm for 3.5 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0068] The rare earth weathering steel is composed of the following components: by mass fraction, 0.22wt% silicon, 0.055wt% carbon, 0.8wt% manganese, 0.58wt% chromium, 0.50wt% copper, 0.30wt% nickel, 0.0011wt% calcium, 0.015wt% titanium, 0.0011wt% phosphorus, 0.0015wt% sulfur, 0.0005wt% lanthanum, and 0.0004wt% cerium;

[0069] Step 2: Preparation of nickel-plated carbon nanotubes:

[0070] Take 5g of carbon nanotubes and 150mL of concentrated nitric acid solution, shake at 77°C for 8h, add 150mL of deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take 0.1g of acidified carbon nanotubes, add 100mL of deionized water, ultrasonically disperse, add 1g of dihydrate stannous chloride sensitizer and 4g of hydrochloric acid, and shake for 18min; filter, wash, dry, add 100mL of deionized water, ultrasonically disperse, add 0.04g of palladium dichloride and 1g of hydrochloric acid, shake for 18min, filter, wash, and dry to obtain treated carbon nanotubes; add the treated carbon nanotubes to a nickel plating solution, react at 35°C for 30min, take out, wash, and dry to obtain nickel-plated carbon nanotubes;

[0071] The nickel plating solution includes the following ingredients: 0.2 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, 1.6 mol / L ammonium chloride, 0.1 mol / L sodium citrate, 0.6 mol / L sodium hypophosphite, 0.004 mol / L lead nitrate, 0.005 mol / L phytic acid, with deionized water as solvent;

[0072] Step 3:

[0073] Preparation of polysilsesquioxane sol A:

[0074] 0.2 g of nickel-plated carbon nanotubes, 0.9 g of glycidyloxypropyltrimethoxysilane, and 40 mL of ethanol were heated to 72° C. and reacted for 60 min. Then, a mixture of 4 g of ethyl orthosilicate, 70 g of methyltriethoxysilane, 20 mL of ethanol, and 20 mL of deionized water was added dropwise, and reacted at 73° C. for 60 min to obtain polysilsesquioxane sol A.

[0075] Preparation of polysilsesquioxane sol B:

[0076] Take 0.2g carbon nanotubes, 0.9g glycidyloxypropyl trimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 72°C for 60min to obtain polysilsesquioxane sol B;

[0077] Step 4: Preparation of high-strength rare earth weathering steel:

[0078] Polysilsesquioxane sol B is sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm and dried at 25°C for 1 hour. Polysilsesquioxane sol A is then sprayed on the surface of polysilsesquioxane sol B with a spraying thickness of 3 μm and dried at 25°C in a horizontal magnetic field for 1 hour with a magnetic field intensity of 0.5 T to obtain high-strength rare earth weathering steel.

[0079] Comparative Example 2: Polysilsesquioxane sol B was not coated, and the rest was the same as Example 1:

[0080] Step 1: Preparation of rare earth weathering steel:

[0081] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1210°C and kept warm for 3.5 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0082] The rare earth weathering steel is composed of the following components: by mass fraction, 0.22wt% silicon, 0.055wt% carbon, 0.8wt% manganese, 0.58wt% chromium, 0.50wt% copper, 0.30wt% nickel, 0.0011wt% calcium, 0.015wt% titanium, 0.0011wt% phosphorus, 0.0015wt% sulfur, 0.0005wt% lanthanum, and 0.0004wt% cerium;

[0083] Step 2: Preparation of nickel-plated carbon nanotubes:

[0084] Take 5g of carbon nanotubes and 150mL of concentrated nitric acid solution, shake at 77°C for 8h, add 150mL of deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take 0.1g of acidified carbon nanotubes, add 100mL of deionized water, ultrasonically disperse, add 1g of dihydrate stannous chloride sensitizer and 4g of hydrochloric acid, and shake for 18min; filter, wash, dry, add 100mL of deionized water, ultrasonically disperse, add 0.04g of palladium dichloride and 1g of hydrochloric acid, shake for 18min, filter, wash, and dry to obtain treated carbon nanotubes; add the treated carbon nanotubes to a nickel plating solution, react at 35°C for 30min, take out, wash, and dry to obtain nickel-plated carbon nanotubes;

[0085] The nickel plating solution includes the following ingredients: 0.2 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, 1.6 mol / L ammonium chloride, 0.1 mol / L sodium citrate, 0.6 mol / L sodium hypophosphite, 0.004 mol / L lead nitrate, 0.005 mol / L phytic acid, with deionized water as solvent;

[0086] Step 3: Preparation of polysilsesquioxane sol A:

[0087] Take 0.2g nickel-plated carbon nanotubes, 0.9g glycidyloxypropyltrimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 73°C for 60min to obtain polysilsesquioxane sol A;

[0088] Step 4: Preparation of high-strength rare earth weathering steel:

[0089] Polysilsesquioxane sol A was sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm, and dried in a horizontal magnetic field at 25° C. for 1 h with a magnetic field intensity of 0.5 T to obtain high-strength rare earth weathering steel.

[0090] Comparative Example 3: No nickel plating is performed on the carbon nanotubes, and the rest is the same as in Example 1:

[0091] Step 1: Preparation of rare earth weathering steel:

[0092] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1210°C and kept warm for 3.5 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0093] The rare earth weathering steel is composed of the following components: by mass fraction, 0.22wt% silicon, 0.055wt% carbon, 0.8wt% manganese, 0.58wt% chromium, 0.50wt% copper, 0.30wt% nickel, 0.0011wt% calcium, 0.015wt% titanium, 0.0011wt% phosphorus, 0.0015wt% sulfur, 0.0005wt% lanthanum, and 0.0004wt% cerium;

[0094] Step 2: Preparation of polysilsesquioxane sol:

[0095] Take 0.2g carbon nanotubes, 0.9g glycidyloxypropyltrimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 72°C for 60min to obtain a polysilsesquioxane sol;

[0096] Step 3: Preparation of high-strength rare earth weathering steel:

[0097] Polysilsesquioxane sol is sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm, and dried at 25°C for 1 hour. Polysilsesquioxane sol is sprayed on the surface of polysilsesquioxane sol again with a spraying thickness of 3 μm, and dried at 25°C for 1 hour to obtain high-strength rare earth weathering steel.

[0098] Comparative Example 4: No phytic acid was added, and the rest was the same as Example 1:

[0099] Step 1: Preparation of rare earth weathering steel:

[0100] Silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum and cerium are taken, smelted and cast to obtain steel ingots, heated to 1210°C and kept warm for 3.5 hours, rolled, cooled and cleaned to obtain rare earth weathering steel;

[0101] The rare earth weathering steel is composed of the following components: by mass fraction, 0.22wt% silicon, 0.055wt% carbon, 0.8wt% manganese, 0.58wt% chromium, 0.50wt% copper, 0.30wt% nickel, 0.0011wt% calcium, 0.015wt% titanium, 0.0011wt% phosphorus, 0.0015wt% sulfur, 0.0005wt% lanthanum, and 0.0004wt% cerium;

[0102] Step 2: Preparation of nickel-plated carbon nanotubes:

[0103] Take 5g of carbon nanotubes and 150mL of concentrated nitric acid solution, shake at 77°C for 8h, add 150mL of deionized water, filter and wash until the carbon nanotubes are neutral, and dry to obtain acidified carbon nanotubes; take 0.1g of acidified carbon nanotubes, add 100mL of deionized water, ultrasonically disperse, add 1g of dihydrate stannous chloride sensitizer and 4g of hydrochloric acid, and shake for 18min; filter, wash, dry, add 100mL of deionized water, ultrasonically disperse, add 0.04g of palladium dichloride and 1g of hydrochloric acid, shake for 18min, filter, wash, and dry to obtain treated carbon nanotubes; add the treated carbon nanotubes to a nickel plating solution, react at 35°C for 30min, take out, wash, and dry to obtain nickel-plated carbon nanotubes;

[0104] The nickel plating solution includes the following ingredients: 0.2 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, 1.6 mol / L ammonium chloride, 0.1 mol / L sodium citrate, 0.6 mol / L sodium hypophosphite, 0.004 mol / L lead nitrate, with deionized water as solvent;

[0105] Step 3:

[0106] Preparation of polysilsesquioxane sol A:

[0107] Take 0.2g nickel-plated carbon nanotubes, 0.9g glycidyloxypropyltrimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 73°C for 60min to obtain polysilsesquioxane sol A;

[0108] Preparation of polysilsesquioxane sol B:

[0109] Take 0.2g carbon nanotubes, 0.9g glycidyloxypropyl trimethoxysilane, and 40mL ethanol, heat to 72°C, react for 60min, then dropwise add a mixture of 4g ethyl orthosilicate, 0.8g lanthanum chloride, 70g methyltriethoxysilane, 20mL ethanol, and 20mL deionized water, react at 72°C for 60min to obtain polysilsesquioxane sol B;

[0110] Step 4: Preparation of high-strength rare earth weathering steel:

[0111] Polysilsesquioxane sol B was sprayed on the surface of rare earth weathering steel with a spraying thickness of 3 μm and dried at 25°C for 1 hour. Polysilsesquioxane sol A was then sprayed on the surface of polysilsesquioxane sol B with a spraying thickness of 3 μm and dried at 25°C in a horizontal magnetic field for 1 hour with a magnetic field intensity of 0.5 T to obtain high-strength rare earth weathering steel.

[0112] experiment:

[0113] The high-strength rare earth weathering steel prepared in Examples 1 to 3 and Comparative Examples 1 to 4 was subjected to performance tests. The high-strength rare earth weathering steel was prepared into a 10 mm × 10 mm × 55 mm sample to test its tensile strength. The acid and alkali resistance of the high-strength rare earth weathering steel was tested by placing the sample in 5% HCl and 9.5% NaOH and immersing it until bubbles appeared on the surface of the coating. The acid and alkali resistance time was recorded, and the data obtained were as follows:

[0114] Tensile strength / Mpa Acid resistance / h Alkali resistance / h Example 1 826 662 487 Example 2 823 660 483 Example 3 827 663 489 Comparative Example 1 822 637 451 Comparative Example 2 820 621 445 Comparative Example 3 817 618 436 Comparative Example 4 821 628 440

[0115] Conclusion: From the comparison of the data in the table, it can be seen that in Comparative Example 1, the rare earth salt lanthanum chloride is not added, the density of the coating becomes worse, and the corrosion resistance of the rare earth weathering steel decreases. In Comparative Example 2, polysilsesquioxane sol B is not coated, and the corrosion resistance of the rare earth weathering steel decreases. In Comparative Example 3, nickel is not plated on the carbon nanotubes, the carbon nanotubes are easy to agglomerate, the corrosive medium is easy to invade, and the corrosion resistance of the coating decreases. In Comparative Example 4, phytic acid is not added to the nickel plating solution, and the corrosion resistance of the carbon nanotubes decreases. Polysilsesquioxane sol A and polysilsesquioxane sol B are prepared in Examples 1 to 3 of the present invention, and the density of the coating is enhanced by adding rare earth salt lanthanum chloride, thereby improving the corrosion resistance and weathering resistance of the rare earth weathering steel. The compounding of polysilsesquioxane sol A and polysilsesquioxane sol B makes the corrosion-resistant coating on the surface of the weathering steel more dense, thereby improving the corrosion resistance of the weathering steel. Nickel-plated carbon nanotubes are added to polysilsesquioxane sol A, and a layer of nickel is plated on the carbon nanotubes using a nickel plating solution. Nickel is a metal with ferromagnetism. A layer of nickel is plated on the carbon nanotubes, so that a dense oxide protective layer is formed on the surface of the carbon nanotubes, which hinders the invasion of corrosive media and improves the corrosion resistance of the coating. Examples 1 to 3 also add phytic acid to the nickel plating solution, and the addition of phytic acid further enhances the corrosion resistance of the carbon nanotubes. Plating a layer of nickel on the carbon nanotubes also makes the carbon nanotubes magnetic, and under the action of a magnetic field, they can be better dispersed, thereby improving the corrosion resistance of rare earth weathering steel.

[0116] 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A process for preparing high-strength rare earth weathering steel, characterized in that: The following steps are involved: Step 1: Take silicon, carbon, manganese, chromium, copper, nickel, calcium, titanium, phosphorus, sulfur, lanthanum, and cerium, smelt and cast to obtain steel ingots, heat to 1200-1220℃ and keep warm for 3-4h, roll, cool and wash to obtain rare earth weathering steel; Step 2: Take nickel-plated carbon nanotubes, glycidyloxypropyltrimethoxysilane, and ethanol, heat to 70-75° C., react for 50-70 minutes, then dropwise add a mixture of ethyl orthosilicate, lanthanum chloride, methyltriethoxysilane, ethanol, and deionized water, react at 70-75° C. for 50-70 minutes to obtain polysilsesquioxane sol A; Take carbon nanotubes, glycidyloxypropyltrimethoxysilane and ethanol, raise the temperature to 70-75°C, react for 50-70 minutes, then drop a mixture of ethyl orthosilicate, lanthanum chloride, methyltriethoxysilane, ethanol and deionized water, react at 70-75°C for 50-70 minutes to obtain polysilsesquioxane sol B; Step 3: spray polysilsesquioxane sol B on the surface of rare earth weathering steel, dry it, and then spray polysilsesquioxane sol A on the surface of polysilsesquioxane sol B, dry it, and obtain high-strength rare earth weathering steel.

2. The process for preparing high-strength rare earth weathering steel according to claim 1, characterized in that: When the polysilsesquioxane sol A is dried, it is in a horizontal magnetic field with a magnetic field strength of 0.5T-0.6T.

3. The process for preparing high-strength rare earth weathering steel according to claim 1, characterized in that: The rare earth weathering steel consists of the following components: in mass fraction, 0.20wt%-0.25wt% of silicon, 0.05wt%-0.06wt% of carbon, 0.55wt%-1.0wt% of manganese, 0.55wt%-0.60wt% of chromium, 0.45wt%-0.55wt% of copper, 0.25wt%-0.35wt% of nickel, 0.0011wt%-0.0012wt% of calcium, 0.013wt%-0.016wt% of titanium, 0.001wt%-0.012wt% of phosphorus, 0.001wt%-0.002wt% of sulfur, 0.0004wt%-0.006wt% of lanthanum, and 0.0003wt%-0.005wt% of cerium.

4. The process for preparing high-strength rare earth weathering steel according to claim 1, characterized in that: The method for preparing the nickel-plated carbon nanotubes comprises: adding the treated carbon nanotubes into a nickel plating solution, reacting at 35-40° C. for 30-40 minutes, taking out, washing, and drying to obtain the nickel-plated carbon nanotubes.

5. The process for preparing high-strength rare earth weathering steel according to claim 4, characterized in that: The nickel plating solution comprises the following components: nickel chloride hexahydrate, nickel sulfate hexahydrate, ammonium chloride, sodium citrate, sodium hypophosphite, lead nitrate, and phytic acid, and deionized water is used as a solvent.

6. The process for preparing high-strength rare earth weathering steel according to claim 4, characterized in that: The preparation method of the treated carbon nanotubes is as follows: taking carbon nanotubes and concentrated nitric acid solution, shaking at 75-80° C. for 7-9 hours, adding deionized water, filtering, washing until the carbon nanotubes are neutral, and drying to obtain acidified carbon nanotubes; taking the acidified carbon nanotubes, adding deionized water, ultrasonically dispersing, adding stannous chloride dihydrate sensitizer and hydrochloric acid, and shaking for 15-20 minutes; Filter, wash, and dry, add 100 mL of deionized water, disperse by ultrasonic, add palladium dichloride and hydrochloric acid, shake for 15-20 minutes, filter, wash, and dry to obtain the treated carbon nanotubes.

7. The process for preparing high-strength rare earth weathering steel according to claim 2, characterized in that: The magnetic field strength is 0.5T.

8. High-strength rare earth weathering steel prepared according to the preparation process of high-strength rare earth weathering steel according to any one of claims 1 to 7.