High-temperature-corrosion-resistant stainless steel gas distribution disc and preparation method thereof

Abstract

The invention discloses a high-temperature-corrosion-resistant stainless steel gas distribution disc and a preparation method thereof, and relates to the technical field of stainless steel machining, stainless steel is subjected to micro-arc oxidation treatment, the high temperature resistance and wear resistance of the surface of the stainless steel are improved, but the corrosion resistance of the stainless steel subjected to micropore treatment needs to be improved. Stainless steel subjected to micro-arc oxidation treatment is subjected to titanium dioxide layer plating treatment, micro-arc oxidation holes provide additional anchoring points, titanium dioxide layer plating treatment is carried out on the basis, the corrosion resistance of the stainless steel is improved, micro-arc oxidation treatment is firstly carried out on the surface of the stainless steel, then titanium dioxide is plated on the surface of the stainless steel, and the corrosion resistance of the stainless steel is improved. And the binding force between the titanium dioxide layer and the stainless steel substrate can be obviously improved. The graphene oxide-titanium dioxide composite sol is added into the electroplating solution, invasion of corrosive media is effectively blocked, the diffusion path of the corrosive media is prolonged through the graphene sheet layer, and the corrosion resistance of the stainless steel is further improved.

Description

Technical Field

[0001] This invention relates to the field of stainless steel processing technology, specifically to a high-temperature corrosion resistant stainless steel gas distribution plate and its preparation method. Background Technology

[0002] The gas distributor plate in gas combustion appliances is a key component affecting flame uniformity and combustion efficiency. Existing gas distributor plates are mainly made of die-cast aluminum alloy or stamped from conventional thin stainless steel sheets. Aluminum alloy parts are prone to deformation above 600℃, leading to unstable flame distribution. Stainless steel is susceptible to localized peeling and rust spots under the influence of NaCl. While arc-spraying a NiCr-Cr3C2 coating onto the stainless steel surface provides high-temperature corrosion resistance, the high porosity of the coating results in low adhesion strength between the coating and the substrate, making it prone to localized peeling. There is an urgent need for a new stainless steel material to improve the overall performance of the gas distributor plate.

[0003] To address the aforementioned issues and improve the high-temperature and corrosion resistance of stainless steel gas distribution plates, this application provides a high-temperature corrosion resistant stainless steel gas distribution plate and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature corrosion resistant stainless steel gas distribution plate and its preparation method, so as to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate includes the following steps:

[0007] S1: Take a stainless steel sheet, punch it to obtain a blank; stretch and press it, and then perform a solution treatment to obtain a stainless steel gas distribution plate substrate;

[0008] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte for micro-arc oxidation treatment, removed and dried to obtain the stainless steel gas distribution plate substrate after micro-arc oxidation treatment.

[0009] S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer to obtain a high-temperature corrosion resistant stainless steel gas distribution plate.

[0010] In S3, the electroplating solution comprises: copper sulfate at 28 g / L-31 g / L, stannous chloride at 3 g / L-4 g / L, zinc sulfate at 7 g / L-9 g / L, potassium pyrophosphate at 250 g / L-255 g / L, sodium dihydrogen phosphate at 8 g / L-9 g / L, potassium citrate at 20 g / L-24 g / L, potassium sodium tartrate at 22 g / L-24 g / L, saccharin at 0.04 g / L-0.05 g / L, and graphene oxide-titanium dioxide composite sol at 13 g / L-15 mL / L.

[0011] More preferably, the electrolyte comprises: 7 g / L-8 g / L sodium silicate, 5 g / L-5.5 g / L sodium tungstate, 2 g / L-4 g / L potassium hydroxide, 2 g / L-4 g / L ethylenediaminetetraacetic acid, 1 g / L-5 g / L aluminum oxide, and 1 g / L-5 g / L silicon carbide.

[0012] A more optimized method for preparing the graphene oxide-titanium dioxide composite sol includes the following steps:

[0013] Step 1: Take γ-mercaptopropyltrimethoxysilane and ethanol, stir evenly to obtain γ-mercaptopropyltrimethoxysilane solution; add γ-mercaptopropyltrimethoxysilane solution dropwise to titanium dioxide sol, heat to 60-65℃, stir for 6-7h, dry to obtain mercaptolated titanium dioxide sol.

[0014] Step 2: Take mercapto-modified titanium dioxide sol and ethanol, ultrasonically disperse for 20-30 min, add modified graphene oxide, ultrasonically disperse for 10-20 min, and obtain graphene oxide-titanium dioxide composite sol.

[0015] A more optimized method for preparing the titanium dioxide sol is as follows: take deionized water and ethanol, stir evenly to obtain a mixture; take ethanol and diethanolamine, stir evenly, add tetrabutyl titanate and the mixture, and continue stirring for 1-2 hours to obtain titanium dioxide sol.

[0016] A more optimized method for preparing the modified graphene oxide is as follows: L-tryptophan and sodium hydroxide are added to deionized water and stirred for 1-2 hours to obtain an L-tryptophan mixture. Graphene oxide is then added and ultrasonically dispersed for 2-3 hours. The mixture is heated to 50-55°C and stirred for 22-26 hours. After filtration and drying, the modified graphene oxide is obtained.

[0017] More preferably, the cleaning solution comprises: 3wt%-4wt% citric acid and 9wt%-10wt% phosphoric acid, using deionized water as a solvent.

[0018] In a more optimized manner, during the micro-arc oxidation treatment in S2, the time is 60-70 min and the current density is 10-15 A / dm².2 The temperature is 25-30℃.

[0019] In a more optimized configuration, in S3, the electroplating temperature is 30-32℃, the electroplating time is 15-20 min, and the current density is 0.2 A / cm². 2 .

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. This invention uses micro-arc oxidation to treat stainless steel, improving its high-temperature resistance and wear resistance. However, the corrosion resistance of the stainless steel after microporous treatment still needs improvement. Therefore, this application applies a titanium dioxide plating layer to the stainless steel after micro-arc oxidation. The micro-arc oxidation pores provide additional anchoring points, and the titanium dioxide plating layer further enhances the corrosion resistance of the stainless steel. Performing micro-arc oxidation on the stainless steel surface first, followed by titanium dioxide plating, significantly improves the adhesion between the titanium dioxide layer and the stainless steel substrate. This application uses a combined micro-arc oxidation and titanium dioxide plating scheme to treat stainless steel, addressing multiple requirements for high-temperature resistance and corrosion resistance.

[0022] 2. This application incorporates a graphene oxide-titanium dioxide composite sol into the electroplating solution. L-tryptophan is used to modify the graphene oxide, making its sheet-like structure thinner. This allows the modified graphene oxide to be better dispersed in the titanium dioxide sol, effectively blocking the intrusion of corrosive media. The graphene sheets extend the diffusion path of the corrosive media, further improving the corrosion resistance of the stainless steel.

[0023] 3. The present invention also uses γ-mercaptopropyltrimethoxysilane to thiolize and modify titanium dioxide sol. The thiol group can complex with metal ions to form a passivation layer, further enhancing the corrosion resistance of stainless steel. Detailed Implementation

[0024] 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.

[0025] The sources and types of the materials involved in this invention are not specifically limited. Exemplary examples include: stainless steel: type: 316L; silicon carbide: particle size: 20-50nm, which can be purchased from Henan Nuoda New Materials Co., Ltd.; alumina: α-type aluminum oxide, particle size: 20-30nm, which can be purchased from Hubei Langbowan Biomedical Co., Ltd.; graphene oxide: micro-flake size: 0.5-3μm, thickness: 0.55-1.2nm, which can be purchased from Aladdin, type: G139803.

[0026] Example 1: A method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate, comprising the following steps:

[0027] Step 1: Preparation of a high-temperature corrosion resistant stainless steel gas distribution plate:

[0028] S1: Take a 316L stainless steel sheet, punch it to obtain a blank; stretch and press it at a speed of 10mm / min, and then perform a solution treatment to obtain the stainless steel gas distribution plate substrate;

[0029] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte solution. Using the stainless steel gas distribution plate substrate as the anode, micro-arc oxidation is performed using a bidirectional pulse power supply for 65 minutes at a current density of 12 A / dm³. 2 The temperature was 27℃. The sample was removed and dried to obtain a stainless steel gas distribution plate substrate after micro-arc oxidation treatment.

[0030] The cleaning solution consists of: 3 wt% citric acid and 9 wt% phosphoric acid, using deionized water as the solvent.

[0031] The electrolyte consists of: 7.5 g / L sodium silicate, 5.2 g / L sodium tungstate, 3 g / L potassium hydroxide, 3 g / L ethylenediaminetetraacetic acid, 4 g / L aluminum oxide, and 4 g / L silicon carbide.

[0032] S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer. The electroplating temperature is 31℃, the electroplating time is 18min, and the current density is 0.2A / cm². 2 A high-temperature corrosion resistant stainless steel gas distribution plate was obtained.

[0033] The electroplating solution consists of: copper sulfate (30 g / L), stannous chloride (3.5 g / L), zinc sulfate (8 g / L), potassium pyrophosphate (252 g / L), sodium dihydrogen phosphate (8.5 g / L), potassium citrate (22 g / L), sodium potassium tartrate (23 g / L), saccharin (0.045 g / L), and graphene oxide-titanium dioxide composite sol (14 mL / L), all in deionized water as solvent.

[0034] Step 2: Preparation of graphene oxide-titanium dioxide composite sol:

[0035] S1: Preparation of modified graphene oxide:

[0036] 1g of L-tryptophan and 0.2g of sodium hydroxide were added to 50mL of deionized water and stirred for 1.5h to obtain an L-tryptophan mixture. 0.2g of graphene oxide was added and ultrasonically dispersed for 2.5h. The temperature was raised to 52℃ and stirred for 24h. The mixture was then filtered and dried to obtain modified graphene oxide.

[0037] S2: Preparation of titanium dioxide sol:

[0038] Take 1 mL of deionized water and 9 mL of ethanol, stir well to obtain a mixture; take 70 mL of ethanol and 6 g of diethanolamine, stir well, add 15 mL of tetrabutyl titanate and the mixture, and continue stirring for 1.5 h to obtain titanium dioxide sol.

[0039] S3: Preparation of thiolized titanium dioxide sol:

[0040] Take 17 mL of γ-mercaptopropyltrimethoxysilane and 150 mL of ethanol, stir well to obtain a γ-mercaptopropyltrimethoxysilane solution; add the γ-mercaptopropyltrimethoxysilane solution dropwise to the titanium dioxide sol, heat to 62 °C, stir for 6.5 h, and dry to obtain a mercapto-modified titanium dioxide sol.

[0041] S4: Take 2g of mercapto-modified titanium dioxide sol and 50mL of ethanol, sonicate for 25min, add 0.2g of modified graphene oxide, sonicate for 18min to obtain graphene oxide-titanium dioxide composite sol.

[0042] Example 2: A method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate, comprising the following steps:

[0043] Step 1: Preparation of a high-temperature corrosion resistant stainless steel gas distribution plate:

[0044] S1: Take a 316L stainless steel sheet, punch it to obtain a blank; stretch and punch it at a speed of 8mm / min, and then perform solution treatment to obtain the stainless steel gas distribution plate substrate;

[0045] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte solution. Using the stainless steel gas distribution plate substrate as the anode, micro-arc oxidation is performed using a bidirectional pulse power supply for 60 minutes at a current density of 10 A / dm³. 2 The temperature was 25℃. The sample was removed and dried to obtain a stainless steel gas distribution plate substrate after micro-arc oxidation treatment.

[0046] The cleaning solution consists of: 3 wt% citric acid and 9 wt% phosphoric acid, using deionized water as the solvent.

[0047] The electrolyte consists of: 7 g / L sodium silicate, 5 g / L sodium tungstate, 2 g / L potassium hydroxide, 2 g / L ethylenediaminetetraacetic acid, 1 g / L aluminum oxide, and 1 g / L silicon carbide.

[0048] S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer. The electroplating temperature is 30℃, the electroplating time is 15min, and the current density is 0.2A / cm². 2 A high-temperature corrosion resistant stainless steel gas distribution plate was obtained.

[0049] The electroplating solution consists of: copper sulfate (28 g / L), stannous chloride (3 g / L), zinc sulfate (7 g / L), potassium pyrophosphate (250 g / L), sodium dihydrogen phosphate (8 g / L), potassium citrate (20 g / L), potassium sodium tartrate (22 g / L), saccharin (0.04 g / L), and graphene oxide-titanium dioxide composite sol (13 mL / L), all in deionized water as solvent.

[0050] Step 2: Preparation of graphene oxide-titanium dioxide composite sol:

[0051] S1: Preparation of modified graphene oxide:

[0052] 1g of L-tryptophan and 0.2g of sodium hydroxide were added to 50mL of deionized water and stirred for 1h to obtain an L-tryptophan mixture. 0.2g of graphene oxide was added and ultrasonically dispersed for 2h. The temperature was raised to 50℃ and stirred for another 22h. The mixture was then filtered and dried to obtain modified graphene oxide.

[0053] S2: Preparation of titanium dioxide sol:

[0054] Take 1 mL of deionized water and 9 mL of ethanol, stir well to obtain a mixture; take 70 mL of ethanol and 6 g of diethanolamine, stir well, add 15 mL of tetrabutyl titanate and the mixture, and continue stirring for 1 h to obtain titanium dioxide sol.

[0055] S3: Preparation of thiolized titanium dioxide sol:

[0056] Take 17 mL of γ-mercaptopropyltrimethoxysilane and 150 mL of ethanol, stir well to obtain a γ-mercaptopropyltrimethoxysilane solution; add the γ-mercaptopropyltrimethoxysilane solution dropwise to the titanium dioxide sol, heat to 60 °C, stir for 6 h, and dry to obtain a mercaptolated titanium dioxide sol.

[0057] S4: Take 2g of mercapto-modified titanium dioxide sol and 50mL of ethanol, sonicate for 20min, add 0.2g of modified graphene oxide, sonicate for 10min to obtain graphene oxide-titanium dioxide composite sol.

[0058] Example 3: A method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate, comprising the following steps:

[0059] Step 1: Preparation of a high-temperature corrosion resistant stainless steel gas distribution plate:

[0060] S1: Take a 316L stainless steel sheet, punch it to obtain a blank; stretch and punch it at a speed of 15mm / min, and then perform a solution treatment to obtain the stainless steel gas distribution plate substrate.

[0061] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte solution. Using the stainless steel gas distribution plate substrate as the anode, micro-arc oxidation is performed using a bidirectional pulse power supply for 70 minutes at a current density of 15 A / dm³. 2 The temperature is 30℃. The sample is removed and dried to obtain a stainless steel gas distribution plate substrate after micro-arc oxidation treatment.

[0062] The cleaning solution consists of: 3 wt% citric acid and 9 wt% phosphoric acid, using deionized water as the solvent.

[0063] The electrolyte consists of: 8 g / L sodium silicate, 5.5 g / L sodium tungstate, 4 g / L potassium hydroxide, 4 g / L ethylenediaminetetraacetic acid, 5 g / L aluminum oxide, and 5 g / L silicon carbide.

[0064] S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer. The electroplating temperature is 32℃, the electroplating time is 20 min, and the current density is 0.2 A / cm². 2 A high-temperature corrosion resistant stainless steel gas distribution plate was obtained.

[0065] The electroplating solution consists of: copper sulfate (31 g / L), stannous chloride (4 g / L), zinc sulfate (9 g / L), potassium pyrophosphate (255 g / L), sodium dihydrogen phosphate (9 g / L), potassium citrate (24 g / L), sodium potassium tartrate (24 g / L), saccharin (0.05 g / L), and graphene oxide-titanium dioxide composite sol (15 mL / L), all in deionized water as solvent.

[0066] Step 2: Preparation of graphene oxide-titanium dioxide composite sol:

[0067] S1: Preparation of modified graphene oxide:

[0068] 1g of L-tryptophan and 0.2g of sodium hydroxide were added to 50mL of deionized water and stirred for 2h to obtain an L-tryptophan mixture. 0.2g of graphene oxide was added and ultrasonically dispersed for 3h. The temperature was raised to 55℃ and stirred for another 26h. The mixture was then filtered and dried to obtain modified graphene oxide.

[0069] S2: Preparation of titanium dioxide sol:

[0070] Take 1 mL of deionized water and 9 mL of ethanol, stir well to obtain a mixture; take 70 mL of ethanol and 6 g of diethanolamine, stir well, add 15 mL of tetrabutyl titanate and the mixture, and continue stirring for 2 h to obtain titanium dioxide sol.

[0071] S3: Preparation of thiolized titanium dioxide sol:

[0072] Take 17 mL of γ-mercaptopropyltrimethoxysilane and 150 mL of ethanol, stir well to obtain a γ-mercaptopropyltrimethoxysilane solution; add the γ-mercaptopropyltrimethoxysilane solution dropwise to the titanium dioxide sol, heat to 65 °C, stir for 7 h, and dry to obtain a mercapto-modified titanium dioxide sol.

[0073] S4: Take 2g of mercapto-modified titanium dioxide sol and 50mL of ethanol, sonicate for 30min, add 0.2g of modified graphene oxide, sonicate for 20min to obtain graphene oxide-titanium dioxide composite sol.

[0074] Comparative Example 1: The stainless steel was not plated with a titanium dioxide layer; all other aspects were the same as in Example 1.

[0075] Step 1: Preparation of a high-temperature corrosion resistant stainless steel gas distribution plate:

[0076] S1: Take a 316L stainless steel sheet, punch it to obtain a blank; stretch and press it at a speed of 10mm / min, and then perform a solution treatment to obtain the stainless steel gas distribution plate substrate;

[0077] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte solution. Using the stainless steel gas distribution plate substrate as the anode, micro-arc oxidation is performed using a bidirectional pulse power supply for 65 minutes at a current density of 12 A / dm³. 2 The temperature was 27℃. The sample was removed and dried to obtain a high-temperature corrosion resistant stainless steel gas distributor.

[0078] The cleaning solution consists of: 3 wt% citric acid and 9 wt% phosphoric acid, using deionized water as the solvent.

[0079] The electrolyte consists of: 7.5 g / L sodium silicate, 5.2 g / L sodium tungstate, 3 g / L potassium hydroxide, 3 g / L ethylenediaminetetraacetic acid, 4 g / L aluminum oxide, and 4 g / L silicon carbide.

[0080] Comparative Example 2: Graphene oxide was not modified with L-tryptophan; all other aspects were the same as in Example 1.

[0081] Step 1: Preparation of a high-temperature corrosion resistant stainless steel gas distribution plate:

[0082] S1: Take a 316L stainless steel sheet, punch it to obtain a blank; stretch and press it at a speed of 10mm / min, and then perform a solution treatment to obtain the stainless steel gas distribution plate substrate;

[0083] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte solution. Using the stainless steel gas distribution plate substrate as the anode, micro-arc oxidation is performed using a bidirectional pulse power supply for 65 minutes at a current density of 12 A / dm³. 2 The temperature was 27℃. The sample was removed and dried to obtain a stainless steel gas distribution plate substrate after micro-arc oxidation treatment.

[0084] The cleaning solution consists of: 3 wt% citric acid and 9 wt% phosphoric acid, using deionized water as the solvent.

[0085] The electrolyte consists of: 7.5 g / L sodium silicate, 5.2 g / L sodium tungstate, 3 g / L potassium hydroxide, 3 g / L ethylenediaminetetraacetic acid, 4 g / L aluminum oxide, and 4 g / L silicon carbide.

[0086] S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer. The electroplating temperature is 31℃, the electroplating time is 18min, and the current density is 0.2A / cm². 2 A high-temperature corrosion resistant stainless steel gas distribution plate was obtained.

[0087] The electroplating solution consists of: copper sulfate (30 g / L), stannous chloride (3.5 g / L), zinc sulfate (8 g / L), potassium pyrophosphate (252 g / L), sodium dihydrogen phosphate (8.5 g / L), potassium citrate (22 g / L), sodium potassium tartrate (23 g / L), saccharin (0.045 g / L), and graphene oxide-titanium dioxide composite sol (14 mL / L), all in deionized water as solvent.

[0088] Step 2: Preparation of graphene oxide-titanium dioxide composite sol:

[0089] S1: Preparation of titanium dioxide sol:

[0090] Take 1 mL of deionized water and 9 mL of ethanol, stir well to obtain a mixture; take 70 mL of ethanol and 6 g of diethanolamine, stir well, add 15 mL of tetrabutyl titanate and the mixture, and continue stirring for 1.5 h to obtain titanium dioxide sol.

[0091] S2: Preparation of thiolized titanium dioxide sol:

[0092] Take 17 mL of γ-mercaptopropyltrimethoxysilane and 150 mL of ethanol, stir well to obtain a γ-mercaptopropyltrimethoxysilane solution; add the γ-mercaptopropyltrimethoxysilane solution dropwise to the titanium dioxide sol, heat to 62 °C, stir for 6.5 h, and dry to obtain a mercapto-modified titanium dioxide sol.

[0093] S3: Take 2g of mercapto-modified titanium dioxide sol and 50mL of ethanol, sonicate for 25min, add 0.2g of graphene oxide, sonicate for 18min to obtain graphene oxide-titanium dioxide composite sol.

[0094] Comparative Example 3: Titanium dioxide sol was not modified with γ-mercaptopropyltrimethoxysilane for thiolization; all other aspects were the same as in Example 1.

[0095] Step 1: Preparation of a high-temperature corrosion resistant stainless steel gas distribution plate:

[0096] S1: Take a 316L stainless steel sheet, punch it to obtain a blank; stretch and press it at a speed of 10mm / min, and then perform a solution treatment to obtain the stainless steel gas distribution plate substrate;

[0097] S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte solution. Using the stainless steel gas distribution plate substrate as the anode, micro-arc oxidation is performed using a bidirectional pulse power supply for 65 minutes at a current density of 12 A / dm³. 2 The temperature was 27℃. The sample was removed and dried to obtain a stainless steel gas distribution plate substrate after micro-arc oxidation treatment.

[0098] The cleaning solution consists of: 3 wt% citric acid and 9 wt% phosphoric acid, using deionized water as the solvent.

[0099] The electrolyte consists of: 7.5 g / L sodium silicate, 5.2 g / L sodium tungstate, 3 g / L potassium hydroxide, 3 g / L ethylenediaminetetraacetic acid, 4 g / L aluminum oxide, and 4 g / L silicon carbide.

[0100] S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer. The electroplating temperature is 31℃, the electroplating time is 18min, and the current density is 0.2A / cm². 2 A high-temperature corrosion resistant stainless steel gas distribution plate was obtained.

[0101] The electroplating solution consists of: copper sulfate (30 g / L), stannous chloride (3.5 g / L), zinc sulfate (8 g / L), potassium pyrophosphate (252 g / L), sodium dihydrogen phosphate (8.5 g / L), potassium citrate (22 g / L), sodium potassium tartrate (23 g / L), saccharin (0.045 g / L), and graphene oxide-titanium dioxide composite sol (14 mL / L), all in deionized water as solvent.

[0102] Step 2: Preparation of graphene oxide-titanium dioxide composite sol:

[0103] S1: Preparation of modified graphene oxide:

[0104] 1g of L-tryptophan and 0.2g of sodium hydroxide were added to 50mL of deionized water and stirred for 1.5h to obtain an L-tryptophan mixture. 0.2g of graphene oxide was added and ultrasonically dispersed for 2.5h. The temperature was raised to 52℃ and stirred for 24h. The mixture was then filtered and dried to obtain modified graphene oxide.

[0105] S2: Preparation of titanium dioxide sol:

[0106] Take 1 mL of deionized water and 9 mL of ethanol, stir well to obtain a mixture; take 70 mL of ethanol and 6 g of diethanolamine, stir well, add 15 mL of tetrabutyl titanate and the mixture, and continue stirring for 1.5 h to obtain titanium dioxide sol.

[0107] S3: Take 2g of mercapto-modified titanium dioxide sol and 50mL of ethanol, sonicate for 25min, add 0.2g of modified graphene oxide, sonicate for 18min to obtain graphene oxide-titanium dioxide composite sol.

[0108] Comparative Example 4: The stainless steel gas distribution plate underwent micro-arc oxidation treatment, and the rest was the same as in Example 1.

[0109] experiment:

[0110] The high-temperature corrosion resistant stainless steel gas distribution plates prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. The plates were kept at 500℃ for 30 minutes and then immersed in 25℃ water for 3 seconds for a thermal shock test, repeated 100 times. The coating surface was observed for any peeling. The data obtained are shown in Table 1 below.

[0111] Table 1

[0112]

[0113] Conclusion: The data comparison in the table shows that, in Comparative Example 1, the corrosion resistance of the stainless steel gas distributor plate significantly decreased after being coated with a titanium dioxide layer. In Comparative Example 2, without L-tryptophan modification of graphene oxide, the dispersibility of graphene oxide was not improved, resulting in decreased corrosion resistance. In Comparative Example 3, without γ-mercaptopropyltrimethoxysilane to thiolize the titanium dioxide sol, the corrosion resistance of the stainless steel gas distributor plate decreased. In Comparative Example 4, the stainless steel gas distributor plate underwent micro-arc oxidation treatment, resulting in decreased adhesion between the titanium dioxide layer and the stainless steel substrate, insufficient interfacial bonding strength, and cracks appearing in the coating during thermal shock testing. Examples 1-3 added a graphene oxide-titanium dioxide composite sol to the electroplating solution. Using L-tryptophan to modify graphene oxide thinned the sheet-like structure of the graphene oxide, allowing the modified graphene oxide to be better dispersed in the titanium dioxide sol, effectively blocking the intrusion of corrosive media. The graphene sheets extended the diffusion path of the corrosive media, further improving the corrosion resistance of the stainless steel. Examples 1-3 use γ-mercaptopropyltrimethoxysilane to thiolize and modify titanium dioxide sol. The thiol groups can complex with metal ions to form a passivation layer, further enhancing the corrosion resistance of stainless steel.

[0114] 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 preparing a high-temperature corrosion-resistant stainless steel gas distribution plate, characterized in that: Includes the following steps: S1: Take a stainless steel sheet, punch it to obtain a blank; stretch and press it, and then perform a solution treatment to obtain a stainless steel gas distribution plate substrate; S2: The stainless steel gas distribution plate substrate is cleaned in a cleaning solution, then placed in an electrolyte for micro-arc oxidation treatment, removed and dried to obtain the stainless steel gas distribution plate substrate after micro-arc oxidation treatment. S3: The stainless steel gas distribution plate substrate after micro-arc oxidation treatment is placed in an electroplating solution to electroplat a titanium dioxide layer to obtain a high-temperature corrosion resistant stainless steel gas distribution plate. In S3, the electroplating solution comprises: copper sulfate at 28 g / L-31 g / L, stannous chloride at 3 g / L-4 g / L, zinc sulfate at 7 g / L-9 g / L, potassium pyrophosphate at 250 g / L-255 g / L, sodium dihydrogen phosphate at 8 g / L-9 g / L, potassium citrate at 20 g / L-24 g / L, potassium sodium tartrate at 22 g / L-24 g / L, saccharin at 0.04 g / L-0.05 g / L, and graphene oxide-titanium dioxide composite sol at 13 g / L-15 mL / L.

2. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 1, characterized in that: The electrolyte comprises: 7 g / L-8 g / L sodium silicate, 5 g / L-5.5 g / L sodium tungstate, 2 g / L-4 g / L potassium hydroxide, 2 g / L-4 g / L ethylenediaminetetraacetic acid, 1 g / L-5 g / L aluminum oxide, and 1 g / L-5 g / L silicon carbide.

3. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 1, characterized in that: The preparation method of the graphene oxide-titanium dioxide composite sol includes the following steps: Step 1: Take γ-mercaptopropyltrimethoxysilane and ethanol, stir evenly to obtain γ-mercaptopropyltrimethoxysilane solution; add γ-mercaptopropyltrimethoxysilane solution dropwise to titanium dioxide sol, heat to 60-65℃, stir for 6-7h, dry to obtain mercaptolated titanium dioxide sol. Step 2: Take mercapto-modified titanium dioxide sol and ethanol, ultrasonically disperse for 20-30 min, add modified graphene oxide, ultrasonically disperse for 10-20 min, and obtain graphene oxide-titanium dioxide composite sol.

4. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 3, characterized in that: The preparation method of the titanium dioxide sol is as follows: take deionized water and ethanol, stir evenly to obtain a mixture; take ethanol and diethanolamine, stir evenly, add tetrabutyl titanate and the mixture, and continue stirring for 1-2 hours to obtain titanium dioxide sol.

5. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 3, characterized in that: The modified graphene oxide is prepared by adding L-tryptophan and sodium hydroxide to deionized water and stirring for 1-2 hours to obtain an L-tryptophan mixture. Graphene oxide is then added and ultrasonically dispersed for 2-3 hours. The temperature is raised to 50-55°C and stirring is continued for 22-26 hours. The mixture is then filtered and dried to obtain the modified graphene oxide.

6. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 1, characterized in that: The cleaning solution comprises: 3wt%-4wt% citric acid and 9wt%-10wt% phosphoric acid, using deionized water as the solvent.

7. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 1, characterized in that: In S2, the micro-arc oxidation treatment lasts for 60-70 minutes, with a current density of 10-15 A / dm². 2 The temperature is 25-30℃.

8. The method for preparing a high-temperature corrosion resistant stainless steel gas distribution plate according to claim 1, characterized in that: In S3, during electroplating, the plating temperature is 30-32℃, the plating time is 15-20 minutes, and the current density is 0.2 A / cm². 2 .

9. A high-temperature corrosion resistant stainless steel gas distributor prepared by the method for preparing a high-temperature corrosion resistant stainless steel gas distributor according to any one of claims 1-8.

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