A valve surface nitriding treatment agent, its preparation method and its use process

Abstract

The present invention discloses a nitriding treatment agent for valve surfaces, a preparation method and a use process thereof, which comprise the following components in parts by weight: 30-70 parts of NaCNO, 10-30 parts of K2CO3, 10-30 parts of KCl, 10-30 parts of NaCl, 5-15 parts of KOH, 2-7 parts of Ce2CO3, 3-5 parts of a catalytic activity promoter, 5-10 parts of an aqueous solution of NaHCO3 with a mass concentration of 5%, C 10 H 16 N2O8 1-3 parts. The cyanate radical decomposes to provide active carbon and nitrogen atoms, and the obtained effective layer has high hardness and good wear resistance, realizing the nitriding treatment of the valve surface. At the same time, the nitriding layer prepared by the present invention is stable and pollution-free, and the cyanide radical is reformed into CNO under the action of the oxidizing component ‑ , realizing the recycling of the salt.

Description

Technical Field

[0001] The present invention relates to the technical field of valve surface treatment agents, and particularly to a valve surface nitriding treatment agent, a preparation method thereof, and a use process thereof. Background Art

[0002] The valve is one of the important components of an internal combustion engine, and its surface quality directly affects the performance and service life of the engine. In order to improve the wear resistance and corrosion resistance of the valve, it is usually necessary to nitride the valve surface. The main processes of the existing nitriding treatment are: 1. Degreasing; 2. Cleaning; 3. Preheating; 4. Nitriding; 5. Quenching in water; 6. Cleaning. With the upgrading of the engine, the requirements for the valve are getting higher and higher. To meet the requirements of the engine, more new valve materials have emerged, and the requirements for the valve surface process are also getting more stringent.

[0003] It is found in the experimental process that the existing commonly used nitriding treatment agents and nitriding treatment processes are difficult to meet various new valve materials and stringent surface treatment processes. The surface protection layer formed by using the commonly used nitriding treatment agent under the traditional process has insufficient hardness, and the surface process is relatively rough. The porosity emergence rate of the surface protection layer is relatively large, and the flatness is insufficient. Even when used for some new valve materials, the problem is more obvious. Based on this situation, corresponding improvements are made to the surface nitriding treatment agent used in the nitriding process and the corresponding nitriding treatment process. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, the abstract of the specification and the title of the invention of this application to avoid obscuring the purpose of this part, the abstract of the specification and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the problems existing in the above-mentioned existing nitriding treatment agents and nitriding treatment processes for valve surfaces, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is: to solve the problem that the existing commonly used nitriding treatment agents and nitriding treatment processes are difficult to meet various new valve materials and stringent surface treatment processes.

[0007] To solve the above technical problem, the present invention provides the following technical solution: A valve surface nitriding treatment agent includes the following components by weight: 30 - 70 parts of NaCNO3, 10 - 30 parts of K2CO3, 10 - 30 parts of KCl, 10 - 30 parts of NaCl, 5 - 15 parts of KOH, 2 - 7 parts of Ce2CO3, 3 - 5 parts of a catalytic activity aid, 5 - 10 parts of an aqueous solution of NaHCO3 with a mass concentration of 5%, C 10 H 16 1 - 3 parts of N2O8.

[0008] As a preferred embodiment of the valve surface nitriding treatment agent of the present invention, it includes the following components by weight: 30 parts of NaCNO, 10 parts of K2CO3, 10 parts of KCl, 10 parts of NaCl, 5 parts of KOH, 2 parts of Ce2CO3, 3 parts of catalytic activity promoter, 5 parts of 5% NaHCO3 aqueous solution by mass concentration, C 10 H 16 1 part of N2O8.

[0009] As a preferred embodiment of the valve surface nitriding treatment agent of the present invention, it includes the following components by weight: 55 parts of NaCNO, 18 parts of K2CO3, 25 parts of KCl, 22 parts of NaCl, 12 parts of KOH, 6 parts of Ce2CO3, 5 parts of catalytic activity promoter, 8 parts of 5% NaHCO3 aqueous solution by mass concentration, C 10 H 16 2 parts of N2O8.

[0010] As a preferred embodiment of the valve surface nitriding treatment agent of the present invention, it includes the following components by weight: 60 parts of NaCNO, 18 parts of K2CO3, 20 parts of KCl, 15 parts of NaCl, 10 parts of KOH, 3 parts of Ce2CO3, 5 parts of catalytic activity promoter, 9 parts of 5% NaHCO3 aqueous solution by mass concentration, C 10 H 16 3 parts of N2O8.

[0011] As a preferred embodiment of the valve surface nitriding treatment agent of the present invention, the catalytic activity promoter is prepared by mixing Mg(OH)2 and Na2SO4 in a mass fraction ratio of 1:1.2.

[0012] To solve the above technical problems, the present invention also provides the following technical solution: A preparation method of a valve surface nitriding treatment agent, using the above raw materials and their ratios of the valve surface nitriding treatment agent, and is prepared through the following steps: S1: Weigh the raw materials according to the weight ratio; S2: Mixing: Grind and mix NaCNO, K2CO3, KCl, NaCl, KOH and Ce2CO3 evenly to obtain a mixture; S3: Nitriding pretreatment: Dissolve the mixture obtained in step S2 with sufficient deionized water. When it is completely dissolved and presents a solution state, add the catalytic activity promoter, increase the stirring frequency, continuously add deionized water until the catalytic activity promoter is completely dissolved in the mixed solution, quickly remove the mixed solution and place it into an electrode catalytic device, apply electricity to the positive and negative electrodes for 5 minutes for ionization assistance, add C 10 H 16N2O8, continuously stir for more than 1 hour to form a uniform liquid; S4: Nitriding: Put the mixed liquid obtained in S3 into a nitriding salt crucible and melt it at 500 °C. After the mixture in the mixed liquid is completely melted, raise the furnace temperature to 550 °C and keep it warm for 8 hours, and at the same time, the water vapor evaporates completely, thus obtaining the nitriding treatment agent for the valve surface.

[0013] As a preferred scheme of the preparation method of the nitriding treatment agent for the valve surface of the present invention, wherein: the electrode of the electrode catalytic device is not less than 6V and not higher than 32V.

[0014] As a preferred scheme of the preparation method of the nitriding treatment agent for the valve surface of the present invention, wherein: in step S3, add C 10 H 16 After continuously stirring N2O8, add an aqueous solution of NaHCO3 with a mass concentration of 5% to ensure that the pH value of the mixed solution is lower than 5 and presents acidity.

[0015] To solve the above technical problems, the present invention also provides the following technical solution: A process for using a nitriding treatment agent for the valve surface, using the above-mentioned nitriding treatment agent for the valve surface, including the following steps: Q1: Degreasing the valve surface; Q2: Cleaning the valve surface; Q3: Preheating the valve surface to above 500 degrees Celsius; Q4: Uniformly spraying the nitriding treatment agent for the valve surface onto the valve surface; Q5: Quenching in water; Q6: Continuously repeat the above steps Q3, Q4 and Q5 for more than 5 times; Q7: Cleaning the valve surface.

[0016] As a preferred scheme of the process for using the nitriding treatment agent for the valve surface of the present invention, wherein: after completing the cleaning of the valve surface in step Q2, place it in an acidic solution, configure a file to perform surface breaking, and after the breaking is completed, perform step Q3.

[0017] The beneficial effects of the present invention: The present invention provides a nitriding treatment agent for the valve surface, a preparation method and a using process thereof. A large dose of sodium cyanate is added to the preparation raw materials, and the cyanate radical decomposes to provide active carbon and nitrogen atoms. The obtained effective layer has high hardness and good wear resistance, realizing the nitriding treatment of the valve surface. At the same time, the nitriding layer prepared by the present invention is stable and pollution-free, and the cyanide radical re-forms CNO under the action of oxidizing components - , realizing the salt recycling and solving the problems that the existing commonly used nitriding treatment agents and nitriding treatment processes are difficult to meet various new valve materials and strict surface treatment processes. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative labor, other drawings can be obtained based on these drawings. Among them:

[0019] Figure 1 It is a process flow chart of a method for preparing a nitriding treatment agent for the valve surface involved in the present invention.

[0020] Figure 2 It is a process flow chart of the process for using the nitriding treatment agent for the valve surface involved in the present invention.

[0021] Figure 3 It is a metallographic schematic diagram of the first nitriding layer obtained by processing in the experimental example of the present invention.

[0022] Figure 4 It is a metallographic schematic diagram of the second nitriding layer obtained by processing in the experimental example of the present invention. Detailed implementation manners

[0023] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific implementation manners of the present invention in conjunction with the drawings in the specification.

[0024] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0025] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an independent or selectively exclusive embodiment from other embodiments.

[0026] The commonly used existing nitriding treatment agents and nitriding treatment processes are difficult to meet various new valve materials and stringent surface treatment processes. The alloy content of valve steel is more than 15%, far exceeding the common 5% alloy content materials such as 40Cr. The high alloy content makes it difficult to nitride the valve, with a slow nitriding rate. Even for the newly adopted high-nickel alloys such as Ni30 and GH4751 in the valve industry, ordinary nitriding agents and processes simply cannot perform nitriding treatment.

[0027] The surface nitriding agent of the present invention has excellent surface activation activity, which can destroy the passivation film formed on the valve steel during processing and storage. In addition, the surface nitriding agent catalyzed by rare earth cerium carbonate has high nitriding activity, so that the surface of the valve product can obtain an ideal nitriding hardening layer.

[0028] Specifically, the present invention provides a valve surface nitriding treatment agent, which comprises the following components by weight: 30-70 parts of NaCNO, 10-30 parts of K2CO3, 10-30 parts of KCl, 10-30 parts of NaCl, 5-15 parts of KOH, 2-7 parts of Ce2CO3, 3-5 parts of catalytic active additive, 5-10 parts of NaHCO3 aqueous solution with a mass concentration of 5%, 10 H 16 N2O8 1~3 parts.

[0029] Specifically, the catalytic active additive is a mixture of Mg(OH)2 and Na2SO4 in a mass fraction of 1:1.2.

[0030] It should be noted that the steps for preparing the catalytically active additive are as follows:

[0031] 1. First, weigh Mg(OH)2 and Na2SO4 in a mass fraction ratio of 1:1.2. In this process, a precise balance can be used for accurate weighing to ensure the accurate mass ratio of the two.

[0032] 2. After weighing, place Mg(OH)2 and Na2SO4 into two dry containers respectively.

[0033] 3. Next, the materials in the two containers are treated with ultrasound. Ultrasonic treatment helps to increase the surface activity of the powdered material, making it easier to disperse in the subsequent mixing process. The treatment time is 5 minutes.

[0034] 4. Place the ultrasonically treated Mg(OH)2 and Na2SO4 in a dry magnetic stirrer respectively and stir at a speed of 400 rpm.

[0035] 5. During the stirring process, gradually add an appropriate amount of water. The speed of adding water should be properly controlled to avoid a violent reaction. Continue stirring for 30 minutes to ensure that Mg(OH)2 and Na2SO4 are fully mixed.

[0036] 6. After stirring, place the mixture in a drying oven and heat it at 100 degrees Celsius for 2 hours. Heating helps to increase the catalytic activity of the mixture.

[0037] 7. After the heating is completed, take out the mixture from the drying oven and put it into a grinder for grinding. During the grinding process, the particle size and dispersibility of the mixture can be adjusted by controlling the grinding time, grinding speed, and grinding intensity.

[0038] 8. After the grinding is completed, sieve the mixture and collect the residue on the sieve. The residue on the sieve is the mixture of catalytically active Mg(OH)2 and Na2SO4.

[0039] 9. Finally, put the residue on the sieve into a sealed container and store it in a dry place.

[0040] It should be noted that C 10 H 16 N2O8 is a multifunctional coordination reagent with the ability to form chelate complexes with various metal ions. It can form stable complexes with divalent metal ions (such as Ca 2 +, Mg2+, Zn2+, etc.) and trivalent metal ions (such as Al3+, Fe3+, etc.).

[0041] Additionally, the present invention also provides a method for preparing a nitriding treatment agent for the valve surface. Select the above raw materials for the nitriding treatment agent for the valve surface and their ratios, and prepare through the following steps:

[0042] S1: Weigh the raw materials according to the weight ratio;

[0043] S2: Mixing: Grind and mix NaCNO, K2CO3, KCl, NaCl, KOH, and Ce2CO3 evenly to obtain a mixture;

[0044] S3: Nitriding pretreatment: Dissolve the mixture obtained in step S2 with sufficient deionized water. When it is completely dissolved and presents a solution state, add a catalytically active auxiliary agent, increase the stirring frequency, and continuously add deionized water until the catalytically active auxiliary agent is completely dissolved in the mixed solution. Quickly remove the mixed solution and place it into an electrode catalytic device. Apply electricity to the positive and negative electrodes for 5 minutes for ionization assistance. Add C 10 H 16 N2O8, and continuously stir for more than 1 hour to form a homogeneous liquid;

[0045] S4: Nitriding: Put the mixed liquid obtained in S3 into a nitriding salt crucible and melt it at 500 °C. After the mixture in the mixed liquid is completely melted, raise the furnace temperature to 550 °C and keep it warm for 8 hours, while the water vapor evaporates completely, then the nitriding treatment agent for the valve surface is obtained.

[0046] Furthermore, the electrodes of the electrode catalytic device are not less than 6V and not higher than 32V. The electrode catalytic device is used to accelerate the dissolution of the catalytically active auxiliary agent on the one hand, and on the other hand, to accelerate the nitriding reaction rate.

[0047] Further, in step S3, add C 10 H 16 After keeping stirring 10 H 16 N2O8, add an aqueous solution of NaHCO3 with a mass concentration of 5% to ensure that the pH value of the mixed solution is lower than 5, presenting an acidic state. Making the mixed solution acidic facilitates the subsequent usage steps and reduces the difficulty of surface roughening.

[0048] Additionally, the present invention also provides a process for using a surface nitriding treatment agent for valve, including the following steps:

[0049] Q1: Degrease the valve surface;

[0050] Q2: Clean the valve surface;

[0051] Q3: Preheat the valve surface to above 500 degrees Celsius;

[0052] Q4: Evenly spray the surface nitriding treatment agent for valve onto the valve surface;

[0053] Q5: Quench in water;

[0054] Q6: Repeat the above steps Q3, Q4, and Q5 for more than 5 times;

[0055] Q7: Clean the valve surface.

[0056] Further, after completing the valve surface cleaning in step Q2, place it in an acidic solution, configure a file to perform surface breaking, and then proceed to step Q3 after the breaking is completed. Breaking the surface is for better nitriding.

[0057] Based on the above, the present invention provides the following embodiments:

[0058] Example 1

[0059] A surface nitriding treatment agent for valve, including the following components by weight: 30 parts of NaCNO3, 10 parts of K2CO3, 10 parts of KCl, 10 parts of NaCl, 5 parts of KOH, 2 parts of Ce2CO3, 3 parts of catalytic activity promoter, 5 parts of an aqueous solution of NaHCO3 with a mass concentration of 5%, C 10 H 16 1 part of 10 H 16 N2O8.

[0060] Example 2

[0061] A surface nitriding treatment agent for valve, including the following components by weight: 55 parts of NaCNO, 18 parts of K2CO3, 25 parts of KCl, 22 parts of NaCl, 12 parts of KOH, 6 parts of Ce2CO3, 5 parts of catalytic activity promoter, 8 parts of an aqueous solution of NaHCO3 with a mass concentration of 5%, C 10 H 16 2 parts of 10 H 16 N2O8.

[0062] Example 3

[0063] A surface nitriding treatment agent for valve, comprising the following components by weight: 60 parts of NaCNO, 18 parts of K2CO3, 20 parts of KCl, 15 parts of NaCl, 10 parts of KOH, 3 parts of Ce2CO3, 5 parts of catalytic activity promoter, 9 parts of 5% NaHCO3 aqueous solution by mass concentration, C 10 H 16 3 parts of N2O8.

[0064] It should be noted that the core utility principle of the surface nitriding treatment agent of the present invention is as follows:

[0065] A large dose of sodium cyanate is added to the raw materials for preparing the surface nitriding treatment agent, and the cyanate radical decomposes to provide active carbon and nitrogen atoms. The specific chemical reaction mechanism is as follows:

[0066] 4CNO - →CO3 2- +2CN - +CO+2[N]

[0067] 2CO→[C]+CO2

[0068] Fe+[C]+[N]→Fe3[C,N]

[0069] This layer is the effective layer obtained by the surface nitriding treatment agent, which has high hardness and good wear resistance, realizing the nitriding / hardening treatment of the valve surface.

[0070] The active stability mechanism of the surface nitriding treatment agent is as follows:

[0071] CN-+[O]→CNO -

[0072] The cyanide radical is re-formed into CNO under the action of the oxidizing component - , realizing the recycling of the salt, and the consumed part can be added according to the amount.

[0073] To verify the effectiveness of the present invention, please refer to the following comparison table of the effects between the comparative examples:

[0074] Table 1: Nitriding result depth of typical materials (mm)

[0075]

[0076] Compared with the commercially available general nitriding salts, the surface nitriding treatment agent of the present invention increases the nitriding depth by more than 20%, improving the nitriding efficiency. Moreover, another advantage of the present invention is that a continuous and complete nitriding layer can be obtained when nitriding high-nickel alloys such as GH4751 and Ni30. Please refer to Figure 3 andFigure 4 。

[0077] To verify the effectiveness of the present invention, please refer to the following specific experimental examples:

[0078] 1. Please refer to Figure 3 , and process the cleaned and preheated GH4751 with the surface nitriding treatment agent after heat preservation. The processing process is to process at 550 °C for 90 minutes. The nitride layer metallographic phase is as Figure 3 shown;

[0079] It can be seen that after the GH4751 is processed with the surface nitriding treatment agent of the present invention, the effective nitride layer is 3.65 μm, which is significantly better than the existing traditional processing.

[0080] 2. Please refer to Figure 4 , and process the cleaned and preheated 4Cr10Si2Mo with the surface nitriding treatment agent after heat preservation. The processing process is to process at 520 °C for 35 minutes. The nitride layer metallographic phase is as Figure 4 shown;

[0081] It can be seen that after the 4Cr10Si2Mo is processed with the surface nitriding treatment agent of the present invention, the effective nitride layer is 8.01 μm, which is also significantly better than the existing traditional processing.

[0082] At the same time, the present invention uses raw materials that are pollution-free and have no safety hazards for production, and the pH value is slightly alkaline and nearly neutral. A small amount of ammonia gas generated during the process can be collected and treated by the equipped tail gas treatment tower, and a small amount of CN - is oxidized by components such as KOH in the formula to CNO - , and no pollution will be generated, and the environmental protection performance is also excellent.

[0083] The present invention provides a valve surface nitriding treatment agent, a preparation method and a use process thereof. A large dose of sodium cyanate is added to the preparation raw materials, and the cyanate radical decomposes to provide active carbon and nitrogen atoms. The obtained effective layer has high hardness and good wear resistance, realizing the nitriding treatment of the valve surface. At the same time, the nitride layer prepared by the present invention is stable and pollution-free, and the cyanide radical is re-formed into CNO - under the action of oxidizing components, realizing the salt recycling, and solving the problem that the existing commonly used nitriding treatment agents and nitriding treatment processes are difficult to meet various new valve materials and strict surface treatment processes.

[0084] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who refer to this disclosure should easily understand that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application (e.g., changes in the dimensions, scales, structures, shapes and proportions of various elements, as well as parameter values (such as temperature, pressure, etc.), installation arrangements, use of materials, colors, orientations, etc.). For example, elements shown as integrally formed may be composed of multiple parts or elements, the positions of the elements may be inverted or otherwise changed, and the nature, number or position of discrete elements may be altered or changed. Accordingly, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures that perform the recited function described herein, and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0085] In addition, in order to provide a concise description of the exemplary embodiments, not all features of the actual embodiments may be described (i.e., those features that are not relevant to the currently contemplated best mode of carrying out the present invention or those that are not relevant to the implementation of the present invention).

[0086] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous specific implementation decisions may be made. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, without undue experimentation, such development efforts will be a routine task of design, manufacturing and production.

[0087] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the invention.

Claims

1. A nitriding treatment agent for valve surfaces, characterized in that, Comprising the following components by weight parts: 30 - 70 parts of NaCNO, 10 - 30 parts of K2CO3, 10 - 30 parts of KCl, 10 - 30 parts of NaCl, 5 - 15 parts of KOH, 2 - 7 parts of Ce2CO3, 3 - 5 parts of catalytic activity promoter, 5 - 10 parts of 5% (mass concentration) aqueous NaHCO3 solution, C 10 H 16 1 - 3 parts of N2O8.

2. The nitriding treatment agent for valve surface according to claim 1, wherein, Comprising the following components by weight parts: 30 parts of NaCNO, 10 parts of K2CO3, 10 parts of KCl, 10 parts of NaCl, 5 parts of KOH, 2 parts of Ce2CO3, 3 parts of catalytic activity promoter, 5 parts of 5% NaHCO3 aqueous solution by mass concentration, C 10 H 16 1 part of N2O8.

3. The nitriding treatment agent for valve surface according to claim 2, wherein Comprising the following components by weight parts: 55 parts of NaCNO, 18 parts of K2CO3, 25 parts of KCl, 22 parts of NaCl, 12 parts of KOH, 6 parts of Ce2CO3, 5 parts of catalytic activity promoter, 8 parts of 5% by mass concentration of NaHCO3 aqueous solution, C 10 H 16 2 parts of N2O8.

4. The nitriding treatment agent for valve surface according to claim 3, characterized in that, Comprising the following components by weight parts: 60 parts of NaCNO, 18 parts of K2CO3, 20 parts of KCl, 15 parts of NaCl, 10 parts of KOH, 3 parts of Ce2CO3, 5 parts of catalytic activity promoter, 9 parts of 5% by mass concentration of NaHCO3 aqueous solution, C 10 H 16 3 parts of N2O8.

5. The nitriding treatment agent for valve surface according to claim 4, characterized in that: The catalytic activity promoter is prepared by mixing Mg(OH)2 and Na2SO4 in a mass fraction ratio of 1:1.

2.

6. A preparation method of a nitriding treatment agent for a valve surface, characterized in that, Select the raw materials and their ratios of the valve surface nitriding treatment agent in the above-mentioned claims 2 to 4, and prepare them through the following steps: S1: Weigh the raw materials according to the weight ratio. S2: Mixing: Grind and mix NaCNO, K2CO3, KCl, NaCl, KOH and Ce2CO3 evenly to obtain a mixture. S3: Nitriding pretreatment: Dissolve the mixture obtained in step S2 with sufficient deionized water. When it is completely dissolved and presents a solution state, add the catalytic activity promoter, increase the stirring frequency, continuously add deionized water until the catalytic activity promoter is completely dissolved in the mixed solution, quickly remove the mixed solution and place it into the electrode catalytic device, apply electricity to the positive and negative electrodes for 5 minutes for ionization assistance, and add C 10 H 16 N2O8, and continuously stir for more than 1 hour to form a homogeneous liquid; S4: Nitriding: Put the mixed liquid obtained in S3 into a nitriding salt crucible and melt it at 500 °C. After the mixture in the mixed liquid is completely melted, raise the furnace temperature to 550 °C and keep it warm for 8 hours, while the water vapor evaporates completely, then the valve surface nitriding treatment agent is obtained. Among them, the electrode of the electrode catalytic device is not less than 6V and not higher than 32V. Among them, in step S3, C is added 10 H 16 After adding N2O8 and keeping stirring, an aqueous solution of NaHCO3 with a mass concentration of 5% is added to ensure that the pH value of the mixed solution is lower than 5, showing acidity.

7. A process for using a nitriding treatment agent for a valve surface, characterized in that, Select the valve surface nitriding treatment agent prepared in the above-mentioned claim 6, including the following steps: Q1: Degrease the valve surface. Q2: Clean the valve surface. Q3: Preheat the valve surface to above 500 degrees Celsius. Q4: Evenly spray the valve surface nitriding treatment agent onto the valve surface. Q5: Quench in water. Q6: Repeat the above steps Q3, Q4 and Q5 for more than 5 times. Q7: Clean the valve surface. Among them, after the valve surface cleaning in step Q2 is completed, place it in an acidic solution, configure a file to perform surface breakage, and then perform step Q3 after the breakage is completed.

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