Workpiece and method of treating a surface thereof

Abstract

The application provides a workpiece and a surface treatment method thereof, which comprises the following steps: surface cleaning and finishing of the workpiece; sand blasting treatment of the finished workpiece by using fine sand, so that a sand blasting treatment workpiece with a surface roughness of Rz=40-70 mu m is obtained; primer spraying on the sand blasting treatment workpiece, and then the workpiece is placed and naturally dried after the primer spraying, so that a workpiece after primer spraying is obtained; primer baking of the workpiece after primer spraying in a heating furnace, so that a primer baking workpiece is obtained; topcoat spraying on the primer baking workpiece, and then the workpiece is placed and naturally dried after the topcoat spraying, so that a workpiece after topcoat spraying is obtained; topcoat sintering of the workpiece after topcoat spraying in the heating furnace, so that a finished sintering workpiece is obtained. The operation method has the characteristics of simplicity and easy implementation; and the workpiece treated by the method has strong corrosion resistance, and the service life of the workpiece can be effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining manufacturing, in particular to a workpiece and a surface treatment method thereof. BACKGROUND

[0002] Corrosion of metal is a phenomenon that metal is destroyed by chemical or electrochemical action of environmental medium. The main object of corrosion is metal, among which the corrosion of steel is the most serious. Nowadays, corrosion brings huge economic losses to the national economy. According to the statistics of industrialized countries, the direct economic loss caused by corrosion is about 1-4% of the total output value of the national economy every year, and about 20% of the steel production is corroded every year, and about 30% of the equipment is scrapped due to corrosion.

[0003] Therefore, it is particularly important to strengthen the treatment of the metal surface to improve the corrosion resistance of the metal product and prolong the service life of the metal product. SUMMARY

[0004] The present application provides a workpiece and a surface treatment method thereof to improve the surface corrosion resistance of the workpiece and prolong the service life of the workpiece.

[0005] The present application provides a surface treatment method of a workpiece, comprising the following steps:

[0006] cleaning and finishing the surface of the workpiece;

[0007] sandblasting the finished workpiece by spraying material to obtain a sandblasted workpiece with a surface roughness of Rz=40-70μm;

[0008] spraying primer on the sandblasted workpiece, and placing the workpiece after spraying the primer to naturally dry to obtain a workpiece after spraying the primer;

[0009] sending the workpiece after spraying the primer into a heating furnace for primer baking to obtain a primer baked workpiece;

[0010] spraying topcoat on the primer baked workpiece, and placing the workpiece after spraying the topcoat to naturally dry to obtain a workpiece after spraying the topcoat;

[0011] sending the workpiece after spraying the topcoat into a heating furnace for topcoat sintering to obtain a finished sintered workpiece.

[0012] Optionally, the total thickness of the primer and the topcoat after drying is 20-30μm;

[0013] The thickness ratio of the primer layer to the topcoat layer is 1:1-2.

[0014] Optionally, the primer baking comprises:

[0015] The workpiece after spraying the primer is sent into a heating furnace, baking protective gas is introduced into the heating furnace, after 5-8 minutes of air supply, the temperature is raised, the temperature raising mode is as follows:

[0016] The workpiece after spraying the primer is heated from room temperature to 100 DEG C at a temperature raising rate of 3-5 DEG C / min, and is kept for 5-10 minutes; then the workpiece is heated from 100 DEG C to 200-240 DEG C at a temperature raising rate of 1-2 DEG C / min, and is kept for 0.5-1 hour; after the baking is finished, the heating is stopped, the workpiece and the heating furnace are cooled together to 80-100 DEG C, then the workpiece is taken out, is placed naturally, and is cooled to room temperature to obtain a baked workpiece of primer.

[0017] Optionally, the topcoat sintering comprises:

[0018] The workpiece after spraying the topcoat is sent into a heating furnace, sintering protective gas is introduced into the heating furnace, after 5-8 minutes of air supply, the temperature is raised, the temperature raising mode is as follows:

[0019] The workpiece after spraying the primer is heated from room temperature to 100 DEG C at a temperature raising rate of 3-5 DEG C / min, and is kept for 5-10 minutes; then the workpiece is heated from 100 DEG C to 200-240 DEG C at a temperature raising rate of 1-2 DEG C / min, and is kept for 0.5-1 hour; after the baking is finished, the heating is stopped, the workpiece and the heating furnace are cooled together to 80-100 DEG C, then the workpiece is taken out, is placed naturally, and is cooled to room temperature to obtain a baked workpiece of primer.

[0020] Optionally, the primer is prepared according to the following method:

[0021] According to weight parts, 8-12 parts of epoxy resin, 4-6 parts of primer curing agent, 1.5-2.2 parts of anti-settling agent, 0.2-0.3 parts of defoaming agent, 30-40 parts of diluent, 0.6-0.8 parts of silane coupling agent and 70-80 parts of corrosion inhibitor are mixed uniformly, then are ground for 2-3 hours under the condition of 40-55 DEG C to obtain slurry, the slurry is aged for 0.5-1 hour, then is passed through a 300-mesh sieve to obtain the primer;

[0022] The corrosion inhibitor comprises zinc powder, aluminum powder and phosphorus iron powder, and the mass ratio is m zinc : m aluminum : m phosphorus iron powder = 1: 1.3-2: 0.05-0.1.

[0023] Optionally, the topcoat is prepared according to the following method:

[0024] The acrylic resin and the fluorocarbon resin are added into butyl acetate according to the ratio of 1:1-2, heated to 50-60 DEG C, stirred at 1000 rpm for 10 minutes to obtain the base material;

[0025] The base material is mixed with 10-15% by weight of the base material of hydrophobic nano-silica, 5-10% by weight of the base material of polytetrafluoroethylene powder, and 1-3% by weight of the base material of graphene, and stirred uniformly at a speed of 300-500 rpm to obtain a premix;

[0026] The premix is mixed with the topcoat curing agent at a weight ratio of 1:0.2-0.3, and aged for 20-30 min to obtain a topcoat.

[0027] Optionally, the blasting material in the sandblasting treatment is one or more of corundum, copper ore sand, quartz sand, iron sand, and sea sand.

[0028] The blasting material is sprayed onto the surface of the workpiece using compressed air with a pressure of 0.4-0.6 MPa.

[0029] Optionally, the primer curing agent comprises one or more of aliphatic amines, alicyclic amines, aromatic amines, polyamides, acid anhydrides, resins, or tertiary amines.

[0030] The anti-settling agent comprises one or more of polyolefin wax, polyamide wax, castor oil derivatives, or organic bentonite.

[0031] The defoaming agent comprises one or more of silicone oil, alcohols, fatty acids, fatty acid esters, phosphate esters, mineral oils, amides, and other organic compounds.

[0032] The diluent is one or more of turpentine, rosin water, toluene, xylene, banana water, gasoline, and fatty alcohol organic compounds.

[0033] Optionally, the baking protective gas comprises nitrogen or argon or a mixture of the two.

[0034] In a second aspect, the application provides a workpiece processed by the surface treatment method of the first aspect, comprising a workpiece body, and a primer layer and a topcoat layer sprayed on the surface of the workpiece body; the thickness ratio of the primer layer to the topcoat layer is 1:1-2.

[0035] The application provides a workpiece and a workpiece surface treatment method, which have the following beneficial effects:

[0036] 1) The surface of the workpiece is subjected to sandblasting treatment, which increases the specific surface area of the workpiece surface, is conducive to the adhesion of subsequent paint or paint, and improves the adhesion effect.

[0037] 2) In the application, the primer and the topcoat are sprayed on the surface of the workpiece, which can improve the corrosion resistance of the workpiece surface, strengthen the performance of the workpiece surface, and prolong the service life of the workpiece.

[0038] 3) In the application, the primer and the topcoat are sprayed on the surface of the workpiece, which can further improve the adhesion of the primer and the topcoat on the surface of the workpiece.

[0039] 4)The workpiece surface treatment method provided by the application has the advantages of easy operation and simplicity, and is suitable for large-scale promotion. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, below the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0041] Figure 1 The structural schematic diagram of the workpiece provided by an embodiment of the application.

[0042] Explanation of reference signs:

[0043] 1, workpiece body; 11, primer layer; 12, topcoat layer. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the application more clear, the technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor also belong to the protection scope of the application.

[0045] The application provides a workpiece surface treatment method, comprising the following steps:

[0046] Surface cleaning and finishing of the workpiece;

[0047] Spraying material is used for sand blasting treatment of the finished workpiece, and a sand blasting treatment workpiece with a surface roughness of Rz=40-70μm is obtained;

[0048] The sand blasting treatment workpiece is sprayed with primer, and after the primer is sprayed, the workpiece is placed and naturally dried to obtain a workpiece after primer spraying;

[0049] The workpiece after primer spraying is sent into a heating furnace for primer baking, and a primer baking workpiece is obtained;

[0050] The primer baking workpiece is sprayed with topcoat, and after the topcoat is sprayed, the workpiece is placed and naturally dried to obtain a workpiece after topcoat spraying;

[0051] The workpiece after topcoat spraying is sent into a heating furnace for topcoat sintering, and a finished product sintering workpiece is obtained.

[0052] In the present application, the surface cleaning and finishing of the workpiece is mainly to remove dust on the surface of the workpiece, and to finish the burrs on the surface of the workpiece which are difficult to remove by sand blasting. The surface of the workpiece is cleaned by solvent cleaning of oil stains, grease, soluble salt and other contaminants. The surface treatment achieves dryness, no dust, no oil stains and other contaminants including soluble salt.

[0053] Sand blasting is to use compressed air as power to form a high-speed jet beam to spray the abrasive (copper ore sand, quartz sand, corundum sand, iron sand, sea sand) at a high speed to the surface of the workpiece to be treated, so that the surface or shape of the workpiece changes. Due to the impact and cutting action of the abrasive on the surface of the workpiece, the surface of the workpiece obtains a certain cleanliness and different roughness, and the mechanical properties of the workpiece surface are improved, so that the fatigue resistance of the workpiece is improved, the adhesion between the workpiece and the coating is increased, the durability of the coating is prolonged, and the leveling and decoration of the coating are also facilitated. In the present application, the abrasive is 80-200 mesh copper ore sand, quartz sand, corundum sand, iron sand and sea sand, and the sand blasting distance is 80-130 mm (the distance between the spray gun and the workpiece).

[0054] In the present application, the air-drying time of the primer and the topcoat is 15-30 minutes, or the operator adjusts according to the specific situation.

[0055] The primer is sprayed to improve the adhesion of the topcoat, increase the fullness of the topcoat, provide alkali resistance, provide corrosion protection and the like, while ensuring uniform absorption of the topcoat to make the paint system achieve the best effect. When spraying the primer, the distance between the spray gun and the workpiece is 15-30 cm, and the paint spraying angle is 45-60°.

[0056] The topcoat is the last layer of the paint system, and the spraying of the topcoat can improve the weather resistance and durability of the paint system. When spraying the topcoat, the distance between the spray gun and the workpiece is 15-30 cm, and the paint spraying angle is 45-60°.

[0057] Optionally, the total thickness of the dried primer and topcoat sprayed on the workpiece is 20-30 μm.

[0058] The thickness ratio of the primer layer to the topcoat layer is 1:1-2.

[0059] In the present application, the spraying thickness of the primer and the topcoat is controlled to be 20-30 μm, so that the sprayed primer and topcoat can be dried in a short time, and the standing time is shortened.

[0060] Optionally, the primer baking comprises:

[0061] The workpiece after spraying the primer is sent into a heating furnace, baking protective gas is introduced into the heating furnace, and the temperature is raised after 5-8 minutes of aeration. The temperature rising mode is:

[0062] The workpiece after spraying the primer is heated from room temperature to 100℃ at a heating rate of 3-5℃ / min, and is kept for 5-10 min; then the workpiece is heated from 100℃ to 200-240℃ at a heating rate of 1-2℃ / min, and is kept for 0.5-1 h; after the baking is finished, the heating is stopped, the workpiece and the heating furnace are cooled together to 80-100℃, then the workpiece is taken out, is placed naturally, and is cooled to room temperature to obtain the workpiece after primer baking.

[0063] In the present application, the baking protective gas introduced into the heating furnace can prevent the components of the primer layer from being oxidized during the baking process, and the baking protective gas can be inert gas such as nitrogen or argon. In an implementable manner, the baking protective gas comprises nitrogen and oxygen, and the content of oxygen is 5-8%vol of the content of the baking protective gas.

[0064] In the present application, the temperature is gradually increased in the above-mentioned manner, which can prevent the workpiece from being damaged due to too fast or uneven temperature increase during the baking process. Similarly, the workpiece after baking is cooled together with the heating furnace, which can slowly cool the workpiece and prevent the workpiece and the primer layer from being damaged due to too fast cooling.

[0065] Optionally, the topcoat sintering comprises:

[0066] The workpiece after spraying the topcoat is sent into the heating furnace, and sintering protective gas is introduced into the heating furnace, and after the gas is introduced for 5-8 min, the temperature is increased, and the temperature increasing manner is as follows:

[0067] The workpiece after spraying the primer is heated from room temperature to 150℃ at a heating rate of 3-5℃ / min, and is kept for 5-10 min; then the workpiece is heated from 150℃ to 260-300℃ at a heating rate of 1-2℃ / min, and is kept for 0.5-1.5 h; after the sintering is finished, the heating is stopped, the workpiece and the heating furnace are cooled together to 80-100℃, then the workpiece is taken out, is placed naturally, and is cooled to room temperature to obtain the finished sintered workpiece.

[0068] In the present application, the sintering of the topcoat can improve the adhesion of the topcoat, and also can make the added components in the topcoat form a film during the sintering process. The sintering protective gas used in the sintering process of the topcoat can comprise argon or nitrogen, or a mixture of the two.

[0069] Optionally, the primer is prepared according to the following method:

[0070] By weight, 8-12 parts of epoxy resin, 4-6 parts of primer curing agent, 1.5-2.2 parts of anti-settling agent, 0.2-0.3 parts of defoaming agent, 30-40 parts of diluent, 0.6-0.8 parts of silane coupling agent and 70-80 parts of corrosion inhibitor are mixed uniformly, and then are ground at 40-55℃ for 2-3 h to obtain a slurry, and the slurry is aged for 0.5-1 h, and then is passed through a 300-mesh sieve to obtain the primer.

[0071] The anticorrosive agent comprises zinc powder, aluminum powder and phosphorus iron powder, and the mass ratio is m 锌 ∶m 铝 ∶m 磷铁粉 =1∶1.3~2∶0.05~0.1.

[0072] In the present application, the primer functions to improve the adhesion of the topcoat, increase the fullness of the topcoat, provide alkali resistance, provide corrosion protection, etc., while ensuring uniform absorption of the topcoat. In the present application, the primer can be diluted to a certain viscosity using a corresponding diluent before use.

[0073] The addition of zinc powder, aluminum powder and phosphorus iron powder can play a role in corrosion protection and corrosion resistance. In an implementable manner, the anticorrosive agent further comprises ferrocene, and the weight ratio is m 锌 ∶m 铝 ∶m 磷铁粉 ∶m 二茂铁 =1∶1.3~2∶0.05~0.1∶0.1~0.15. In the present application, the addition of zinc powder in the primer formulation can play a sacrificial anode protection role in the later use process of the workpiece. The addition of aluminum powder can form a dense aluminum oxide film due to the easy oxidation of aluminum, thereby playing a corrosion protection effect. The combination of zinc powder, aluminum powder and phosphorus iron powder can improve the protection and corrosion resistance of the coating on the surface of the workpiece. Moreover, in the baking process, the protective gas contains a small amount of oxygen (5~8%vol of the protective gas content), which can help the aluminum powder in the primer to form an aluminum oxide film and can oxidize part of the zinc into extremely difficultly soluble zinc oxide, and the volume expands to fill the pores and defects in the coating, making the coating more tightly bonded, effectively blocking the penetration of oxygen, water and other corrosive media, thereby improving the corrosion resistance.

[0074] Optionally, the topcoat is prepared according to the following method:

[0075] The acrylic resin and fluorocarbon resin are added to butyl acetate in a ratio of 1∶1~2, heated to 50~60℃, and stirred at a speed of 1000 rpm for 10 min to obtain a base material;

[0076] Hydrophobic nanosilica in an amount of 10~15% by weight of the base material, polytetrafluoroethylene powder in an amount of 5~10% by weight of the base material, and graphene in an amount of 1~3% by weight of the base material are added to the base material, and stirred uniformly at a speed of 300~500 rpm to obtain a premix;

[0077] The premix and the topcoat curing agent are mixed in a weight ratio of 1∶0.2~0.3, and aged for 20~30 min to obtain the topcoat.

[0078] In this application, the topcoat using the above-mentioned components can improve the non-stickiness of the topcoat layer and reduce the adhesion of dirt to the surface of the treated workpiece. In this application, the topcoat can be diluted to a certain viscosity using a suitable thinner before use.

[0079] Optionally, the abrasive used in the sandblasting process is one or more of the following: corundum, copper ore sand, quartz sand, iron sand, and sea sand.

[0080] The abrasive is sprayed onto the workpiece surface using compressed air at a pressure of 0.4~0.6MPa.

[0081] In this application, during sandblasting, the distance between the sandblasting nozzle and the workpiece is 80~130mm. The appropriate abrasive material can be selected based on actual needs during use.

[0082] Optionally, the primer curing agent includes one or more of aliphatic amines, cycloaliphatic amines, aromatic amines, polyamides, acid anhydrides, resins, or tertiary amines;

[0083] The anti-settling agent includes one or more of polyolefin wax, polyamide wax, castor oil derivatives, or organobentonite.

[0084] The defoamer includes one or more organic compounds such as silicone oil, alcohol, fatty acid, fatty acid ester, phosphate ester, mineral oil, and amide.

[0085] The diluent is one or more of the following: turpentine, rosin, toluene, xylene, banana oil, gasoline, and fatty alcohols.

[0086] In this application, the aforementioned primer curing agent, anti-settling agent, defoamer, and thinner are inexpensive and readily available, effectively reducing production costs. Commercially available topcoat curing agents can be used.

[0087] Optionally, the baking protective gas includes nitrogen or argon or a mixture of both.

[0088] Similarly, sintering protective gases include nitrogen or argon or a mixture of both.

[0089] Secondly, such as Figure 1 As shown, this application provides a workpiece processed by the surface treatment method described in the first aspect above, including a workpiece body 1, wherein the surface of the workpiece body 1 is coated with a primer layer 11 and a topcoat layer 12; the thickness ratio of the primer layer to the topcoat layer is 1:1~2.

[0090] In this application, spraying a primer layer 11 and a topcoat layer 12 onto the surface of the workpiece can improve the surface properties of the workpiece and extend its service life. Example 1

[0091] A workpiece is produced by the following method:

[0092] S101, surface cleaning and finishing of the workpiece.

[0093] S102, the workpiece after finishing is sprayed with compressed air at a pressure of 0.4 MPa to the surface of the workpiece, and the surface roughness of the workpiece after sand blasting treatment is Rz=40-70 μm.

[0094] S103, the workpiece after sand blasting is sprayed with primer, and the workpiece is placed after spraying the primer and naturally dried to obtain the workpiece after spraying the primer.

[0095] The primer is prepared as follows:

[0096] According to the weight part, 8 parts of epoxy resin E-44, 4 parts of curing agent (polyamide 650), 1.5 parts of anti-settling agent (polyamide wax), 0.2 parts of defoaming agent (BYK-141), 30 parts of diluent (dichloromethane and n-butanol mixed at a volume ratio of 7:3), 0.6 parts of silane coupling agent (KH-560) and 70 parts of corrosion inhibitor are mixed uniformly, then grinded at 40℃ for 2h to obtain slurry, and then the slurry is aged for 0.5h and sieved through a 300 mesh sieve to obtain the primer.

[0097] The corrosion inhibitor includes zinc powder, aluminum powder and phosphorus iron powder, and the mass ratio is m 锌 ∶m 铝 ∶m 磷铁粉 =1∶1.3∶0.05.

[0098] S104, the workpiece after spraying the primer is sent into the heating furnace for primer baking, the workpiece after spraying the primer is sent into the heating furnace, nitrogen gas (purity>99.99%) is introduced into the heating furnace, and the temperature is raised after 5 minutes of aeration, and the temperature rising mode is:

[0099] The workpiece after spraying the primer is heated from room temperature to 100℃ at a rate of 3℃ / min, and kept for 5min. Then the workpiece is heated from 100℃ to 200℃ at a rate of 1℃ / min, and kept for 1h. After the baking is finished, the heating is stopped, the workpiece and the heating furnace are cooled together to 80℃, then the workpiece is taken out and naturally placed, and cooled to room temperature to obtain the primer baked workpiece.

[0100] S105, the primer baked workpiece is sprayed with topcoat, and the workpiece is placed after spraying the topcoat and naturally dried to obtain the workpiece after spraying the topcoat.

[0101] The topcoat is prepared as follows:

[0102] The thermosetting acrylic resin (AC1038 type) and fluorocarbon resin (JF-3X) are added to butyl acetate at a ratio of 1:1, heated to 50℃, stirred at a speed of 1000 rpm for 10 min to obtain the base material.

[0103] The base material is mixed with 10% by weight of the base material of hydrophobic nanosilica (SP15), 10% by weight of the base material of polytetrafluoroethylene micro powder (particle size of 0.5-15 μm), and 1% by weight of the base material of graphene, and stirred uniformly at a speed of 300 rpm to obtain a premix.

[0104] The premix is mixed with the topcoat curing agent (N3390) at a weight ratio of 1:0.2, and aged for 20 min to obtain a topcoat.

[0105] S106, the workpiece after spraying the topcoat is sent into the heating furnace for topcoat sintering, the workpiece after spraying the topcoat is sent into the heating furnace, nitrogen gas (purity > 99.99%) is introduced into the heating furnace, the temperature is raised after 5 min of aeration, and the temperature is raised in the following way:

[0106] The workpiece after spraying the primer is heated from room temperature to 150℃ at a rate of 3℃ / min, and kept for 5 min. Then the workpiece is heated from 150℃ to 260-300℃ at a rate of 1℃ / min, and kept for 0.5 h. After sintering, the heating is stopped, the workpiece and the heating furnace are cooled together to 80℃, then the workpiece is taken out, and naturally placed, cooled to room temperature to obtain a finished sintered workpiece.

[0107] The total thickness of the dried primer and topcoat sprayed on the workpiece is 20 μm.

[0108] The thickness ratio of the primer layer to the topcoat layer is 1:1. Example 2

[0109] A workpiece is processed by the following method:

[0110] S201, the workpiece is surface cleaned and trimmed.

[0111] S202, the trimmed workpiece is sprayed with compressed air at a pressure of 0.6 MPa by using diamond sand to spray the surface of the workpiece, to obtain a sandblasted workpiece with a surface roughness of Rz=40-70 μm.

[0112] S203, the sandblasted workpiece is sprayed with primer, and the workpiece is placed and naturally dried after spraying the primer to obtain a workpiece after spraying the primer.

[0113] The primer is prepared by the following method:

[0114] According to parts by weight, 12 parts of epoxy resin E-44, 6 parts of curing agent (polyamide 650), 2.2 parts of anti-settling agent (polyamide wax), 0.3 parts of defoaming agent (BYK-141), 40 parts of diluent (mixed with n-butanol in a volume ratio of 7:3), 0.8 parts of silane coupling agent (KH-560) and 80 parts of resist are mixed uniformly, then grinded at 55℃ for 3h to obtain a slurry, and then the slurry is aged for 1h and sieved through a 300 mesh sieve to obtain a primer.

[0115] The resist includes zinc powder, aluminum powder and phosphorus iron powder, and the mass ratio is m 锌 ∶m 铝 ∶m 磷铁粉 =1∶2∶0.1.

[0116] S204, the workpiece after spraying the primer is sent into the heating furnace for primer baking, the workpiece after spraying the primer is sent into the heating furnace, nitrogen gas (purity > 99.99%) is introduced into the heating furnace, after 8min of aeration, the temperature is raised, and the temperature rising mode is:

[0117] The workpiece after spraying the primer is heated from room temperature to 100℃ at a temperature rising rate of 5℃ / min, and kept for 10min. Then the workpiece is heated from 100℃ to 240℃ at a temperature rising rate of 2℃ / min, and kept for 0.5h. After baking, the heating is stopped, the workpiece and the heating furnace are cooled together to 100℃, then the workpiece is taken out, and naturally placed, cooled to room temperature, to obtain the primer baked workpiece.

[0118] S205, the primer baked workpiece is sprayed with topcoat, and after spraying the topcoat, the workpiece is placed, naturally dried, to obtain the workpiece after spraying the topcoat.

[0119] The topcoat is prepared according to the following method:

[0120] The (thermosetting acrylic resin (AC1038 type) and fluorocarbon resin (JF-3X) are added to butyl acetate in a ratio of 1:2, heated to 60℃, stirred at a speed of 1000rpm for 10min, to obtain the base material.

[0121] Hydrophobic nanosilica (SP15) of 15% of the weight of the base material, polytetrafluoroethylene powder (particle size of 0.5-15μm) of 5% of the weight of the base material, and graphene of 3% of the weight of the base material are added to the base material, and stirred uniformly at a speed of 300-500rpm to obtain a premix.

[0122] The premix and the topcoat curing agent (N3390) are mixed in a weight ratio of 1:0.3, aged for 30min to obtain the topcoat.

[0123] S206, the workpiece after spraying the finish paint is sent into the heating furnace for finish paint sintering, the workpiece after spraying the finish paint is sent into the heating furnace, nitrogen gas (purity > 99.99%) is introduced into the heating furnace, after 8 minutes of aeration, the temperature is raised, and the temperature raising mode is:

[0124] The workpiece after spraying the primer is heated from room temperature to 150℃ at a temperature raising rate of 5℃ / min, and is kept for 10 minutes. Then the workpiece is heated from 150℃ to 300℃ at a temperature raising rate of 2℃ / min, and is kept for 0.5h. After sintering, the heating is stopped, the workpiece and the heating furnace are cooled to 100℃ together, then the workpiece is taken out, and is naturally placed and cooled to room temperature to obtain a finished sintered workpiece.

[0125] The total thickness of the primer and the finish paint after drying is 30μm.

[0126] The thickness ratio of the primer layer and the finish paint layer is 1:2. Example 3

[0127] A workpiece is processed by the following method:

[0128] S301, the workpiece is subjected to surface cleaning and finishing.

[0129] S302, the finished workpiece is subjected to sand blasting treatment by spraying compressed air with a pressure of 0.5MPa to the surface of the workpiece by using diamond sand, to obtain a sand blasting treated workpiece with a surface roughness of Rz=40~70μm.

[0130] S303, the sand blasting treated workpiece is sprayed with primer, and the workpiece is placed and naturally dried after spraying the primer, to obtain a workpiece after spraying the primer.

[0131] The primer is prepared by the following method:

[0132] According to weight parts, 10 parts of epoxy resin E-44, 5 parts of curing agent (polyamide 650), 1.8 parts of anti-settling agent (polyamide wax), 0.2 parts of defoaming agent (BYK-141), 35 parts of diluent (dichlorobenzene and n-butanol mixed in a volume ratio of 7:3), 0.7 parts of silane coupling agent (KH-560) and 75 parts of corrosion inhibitor are uniformly mixed, and then grinded at 45℃ for 2.5h to obtain a slurry. The slurry is aged for 0.8h, and then passed through a 300 mesh sieve to obtain the primer.

[0133] The corrosion inhibitor includes zinc powder, aluminum powder and phosphorus iron powder, and the mass ratio is m 锌 ∶m 铝 ∶m 磷铁粉 =1∶1.5∶0.08.

[0134] S304, the workpiece after spraying primer is sent into the heating furnace for primer baking, the workpiece after spraying primer is sent into the heating furnace, nitrogen gas (purity > 99.99%) is introduced into the heating furnace, after 7 minutes of aeration, the temperature is raised, the temperature rising mode is:

[0135] The workpiece after spraying primer is heated from room temperature to 100℃ at a heating rate of 4℃ / min, and is kept for 8min. Then the workpiece is heated from 100℃ to 220℃ at a heating rate of 1.5℃ / min, and is kept for 0.8h. After baking, the heating is stopped, the workpiece and the heating furnace are cooled together to 90℃, then the workpiece is taken out, and is naturally placed, and is cooled to room temperature, to obtain the primer baking workpiece.

[0136] S305, the primer baking workpiece is sprayed with topcoat, and after spraying topcoat, the workpiece is placed, and is naturally dried, to obtain the workpiece after spraying topcoat.

[0137] The topcoat is prepared according to the following method:

[0138] The (thermosetting acrylic resin (AC1038 type) and fluorocarbon resin (JF-3X) are added into butyl acetate in a ratio of 1:1.5, heated to 55℃, stirred at a speed of 1000rpm for 10min, to obtain the base material.

[0139] The base material is added with 12% of hydrophobic nanosilica (SP15) by weight of the base material, 8% of polytetrafluoroethylene micro powder (particle size of 0.5-15μm) by weight of the base material, and 2% of graphene by weight of the base material, and is uniformly stirred at a speed of 400rpm, to obtain the premix.

[0140] The premix is mixed with the topcoat curing agent (N3390) in a weight ratio of 1:0.25, and is aged for 25min to obtain the topcoat.

[0141] S306, the workpiece after spraying topcoat is sent into the heating furnace for topcoat sintering, the workpiece after spraying topcoat is sent into the heating furnace, nitrogen gas (purity > 99.99%) is introduced into the heating furnace, after 7 minutes of aeration, the temperature is raised, the temperature rising mode is:

[0142] The workpiece after spraying primer is heated from room temperature to 150℃ at a heating rate of 4℃ / min, and is kept for 8min. Then the workpiece is heated from 150℃ to 280℃ at a heating rate of 1.5℃ / min, and is kept for 0.8h. After sintering, the heating is stopped, the workpiece and the heating furnace are cooled together to 90℃, then the workpiece is taken out, and is naturally placed, and is cooled to room temperature to obtain the finished sintered workpiece.

[0143] The total thickness of the dried primer and topcoat sprayed on the workpiece is 27μm.

[0144] The thickness ratio of the primer layer and the topcoat layer is 1:1.5. Example 4

[0145] A workpiece is processed by the following method:

[0146] S401, surface cleaning and finishing of the workpiece.

[0147] S402, the finished workpiece is sprayed with compressed air at a pressure of 0.55 MPa to the surface of the workpiece, and the surface roughness of the workpiece is Rz=40-70 μm.

[0148] S403, the sandblasted workpiece is sprayed with primer, and the workpiece is placed after spraying the primer and naturally dried to obtain the workpiece after spraying the primer.

[0149] The primer is prepared by the following method:

[0150] According to the weight part, 10 parts of epoxy resin E-44, 5 parts of curing agent (polyamide 650), 2 parts of anti-settling agent (polyamide wax), 0.2 parts of defoaming agent (BYK-141), 35 parts of diluent (dichloromethane and n-butanol mixed at a volume ratio of 7:3), 0.75 parts of silane coupling agent (KH-560) and 78 parts of corrosion inhibitor are mixed uniformly, then grinded at 50℃ for 2.5h to obtain slurry, and the slurry is aged for 0.5h and then sieved through a 300 mesh sieve to obtain the primer.

[0151] The corrosion inhibitor includes zinc powder, aluminum powder and phosphorus iron powder, and the mass ratio is m 锌 ∶m 铝 ∶m 磷铁粉 =1∶1.5∶0.05.

[0152] S404, the workpiece after spraying the primer is sent into the heating furnace for primer baking, the workpiece after spraying the primer is sent into the heating furnace, nitrogen gas (purity>99.99%) is introduced into the heating furnace, and the temperature is raised after 5 minutes of aeration, and the temperature is raised in the following way:

[0153] The workpiece after spraying the primer is heated from room temperature to 100℃ at a rate of 3℃ / min, and kept for 10min. Then the workpiece is heated from 100℃ to 200℃ at a rate of 1.5℃ / min, and kept for 0.5h. After the baking is finished, the heating is stopped, the workpiece and the heating furnace are cooled together to 80℃, and then the workpiece is taken out and naturally placed to cool to room temperature to obtain the primer baked workpiece.

[0154] S405, the primer baked workpiece is sprayed with topcoat, and the workpiece is placed after spraying the topcoat and naturally dried to obtain the workpiece after spraying the topcoat.

[0155] The topcoat is prepared by the following method:

[0156] The thermosetting acrylic resin (AC1038 type) and fluorocarbon resin (JF-3X) were added into butyl acetate in a ratio of 1:1.5, heated to 60℃, stirred at a speed of 1000 rpm for 10 min, to obtain the base material.

[0157] The hydrophobic nanosilica (SP15) was added into the base material at a weight ratio of 12%, the polytetrafluoroethylene powder (particle size of 0.5-15 μm) was added into the base material at a weight ratio of 10%, and the graphene was added into the base material at a weight ratio of 2%, and stirred uniformly at a speed of 500 rpm, to obtain the premix.

[0158] The premix was mixed with the topcoat curing agent (N3390) at a weight ratio of 1:0.25, and aged for 30 min to obtain the topcoat.

[0159] S406, the workpiece after spraying the topcoat was sent into the heating furnace for topcoat sintering, the workpiece after spraying the topcoat was sent into the heating furnace, nitrogen (purity > 99.99%) was introduced into the heating furnace, and the temperature was raised after 5 min of aeration, and the temperature was raised in the following way:

[0160] The workpiece after spraying the primer was heated from room temperature to 150℃ at a heating rate of 3℃ / min, and kept for 10 min. Then the workpiece was heated from 150℃ to 280℃ at a heating rate of 1.5℃ / min, and kept for 1 h. After sintering, the heating was stopped, the workpiece and the heating furnace were cooled together to 100℃, and then the workpiece was taken out and naturally placed, and cooled to room temperature to obtain the finished sintered workpiece.

[0161] The total thickness of the dried primer and topcoat sprayed on the workpiece was 30 μm.

[0162] The thickness ratio of the primer layer to the topcoat layer was 1:2. Example 5

[0163] S501, same as S401.

[0164] S502, same as S402.

[0165] S503, the remaining operations are the same as S403, except that the ferrocene is also included in the resist, and the weight ratio m 锌 ∶m 铝 ∶m 磷铁粉 ∶m 二茂铁 =1:1.5:0.05:0.12.

[0166] S504, same as S404.

[0167] S505, same as S405.

[0168] S506, same as S406. Example 6

[0169] S601, same as S401.

[0170] S602, same as S402.

[0171] S603, same as S403.

[0172] S604, same as S404 except that the baking protective gas further contains 6% vol oxygen.

[0173] S605, same as S405.

[0174] S606, same as S406. Example 7

[0175] S701, same as S401.

[0176] S702, same as S402.

[0177] S703, same as S403 except that the resist further contains ferrocene, and the weight ratio m 锌 ∶m 铝 ∶m 磷铁粉 ∶m 二茂铁 = 1:1.5:0.05:0.12.

[0178] S704, same as S404 except that the baking protective gas further contains 6% vol oxygen.

[0179] S705, same as S405.

[0180] S706, same as S406.

[0181] Comparative Example 1

[0182] D101, same as S401.

[0183] D102, same as S402.

[0184] D103, same as S403.

[0185] D104, same as S404 except that the baking protective gas is air.

[0186] D105, same as S405.

[0187] D106, same as S406.

[0188] Comparative Example 2

[0189] D201, same as S401.

[0190] D202, same as S402.

[0191] D203, the rest of the operation is the same as S403, except that the resist also includes ferrocene, and the weight ratio m 锌 ∶m 铝 ∶m 磷铁粉 ∶m 二茂铁 =1∶1.5∶0.05∶0.12.

[0192] D204, the rest of the operation is the same as S404, except that the baking protective gas is air.

[0193] D205, the same as S405.

[0194] D206, the same as S406.

[0195] Comparative Example 3

[0196] D301, the same as S401.

[0197] D302, the same as S402.

[0198] D303, the same as S403.

[0199] D304, the rest of the operation is the same as S404, except that the baking protective gas also contains 2%vol of oxygen.

[0200] D305, the same as S405.

[0201] D306, the same as S406.

[0202] Comparative Example 4

[0203] D401, the same as S401.

[0204] D402, the same as S402.

[0205] D403, the same as S403.

[0206] D404, the rest of the operation is the same as S404, except that the baking protective gas also contains 15%vol of oxygen.

[0207] D405, the same as S405.

[0208] D406, the same as S406.

[0209] Comparative Example 5

[0210] D501, the same as S401.

[0211] D502, the same as S402.

[0212] D503, the rest of the operation is the same as S403, except that the resist in the primer only includes zinc powder.

[0213] D504, the same as S404.

[0214] D505, the rest of the operation is the same as S405, except that the formula of the topcoat does not include polytetrafluoroethylene micro powder and hydrophobic nanosilica.

[0215] D506, the same as S406.

[0216] Comparative Example 6

[0217] D601, the same as S401.

[0218] D602, the same as S402.

[0219] D603, the same as S403.

[0220] D604, the rest of the operation is the same as S404, except that the baking protective gas is air.

[0221] D605, the same as S405.

[0222] D606, the rest of the operation is the same as S406, except that the sintering protective gas is air.

[0223] Comparative Example 7

[0224] D701, the same as S401.

[0225] D702, the same as S402.

[0226] D703, the same as S403.

[0227] D704, the same as S404.

[0228] D705, the same as S405.

[0229] D706, the rest of the operation is the same as S406, except that the sintering protective gas is air.

[0230] The workpieces treated by the methods of the above-mentioned Examples 1 to 7 and Comparative Examples 1 to 4 are tested by the following method, and each of the examples and comparative examples has 3 parallel experiments, and the average value is taken. When measuring, it needs to be noted that in all examples and comparative examples, the total thickness of the primer layer + topcoat layer is controlled to be 30 μm ± 0.5 μm, the thickness ratio of the primer layer and the topcoat layer is 1:2, and the surface treatment of the sample is the same surface roughness.

[0231] Experimental Example 1

[0232] Neutral salt spray resistance test:

[0233] The workpieces treated by the methods of the above-mentioned Examples 1-7 and Comparative Examples 1-5 were subjected to salt spray resistance test according to the method provided in GB / T1771-2007 "Determination of Resistance to Neutral Salt Spray of Paint and Varnish" (the sample was not subjected to scratch treatment), and the rust point of the sample was taken as the end point of the test, and the results are shown in Table 1:

[0234] Adhesion test:

[0235] The workpieces treated by the methods of the above-mentioned Examples 1-7 and Comparative Examples 1-5 were subjected to adhesion test according to GB / T5210-2006 "Paint and Varnish Adhesion Test by Pull-off Method".

[0236] Table 1

[0237]

[0238] The results of Table 1 above show that the workpieces treated by the workpiece surface treatment method of the present application have strong corrosion resistance.

[0239] Experimental Example 2

[0240] Hydrophobic and oleophobic test:

[0241] The contact angle of the surface of the coating sample was measured by using an OCA15pro video optical contact angle measuring instrument.

[0242] The specific method is as follows: the droplet parameter is adjusted to 5 μL in advance. The test sample is placed horizontally on the test table, and the droplet is injected onto the surface of the sample by using the pendant droplet method, and the contact angle is tested after stabilization. The test method includes machine test and manual test. When the contact angle is obviously less than 150°, the machine program is used for automatic test; when the contact angle is close to or exceeds 150°, the five-point circle drawing method is used for manual test. For the same sample, three different uniform distribution positions are selected for test, and the average value of the test results is taken as the final contact angle measurement value of the sample.

[0243] In the hydrophobic test, tap water or distilled water was used for test; in the oleophobic test, test oil was prepared by mixing soybean oil and hexadecane in a volume ratio of 3:1. The measurement results are shown in Table 2:

[0244] Table 2

[0245]

[0246] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for surface treatment of a workpiece, characterized in that, Includes the following steps: Clean and trim the surface of the workpiece; The repaired workpiece is sandblasted with abrasive to obtain a sandblasted workpiece with a surface roughness of Rz=40~70μm. Apply primer to the sandblasted workpiece, and after the primer is applied, place the workpiece to air dry naturally to obtain the workpiece with primer applied. The workpiece after being coated with primer is sent into a heating furnace for primer baking to obtain a primer-baked workpiece. After the primer is baked, the topcoat is sprayed onto the workpiece. After the topcoat is sprayed, the workpiece is placed to air dry naturally, and the workpiece with the topcoat is obtained. The workpiece after being coated with topcoat is sent into a heating furnace for topcoat sintering to obtain the finished sintered workpiece. The primer is prepared according to the following method: By weight, 8-12 parts epoxy resin, 4-6 parts primer curing agent, 1.5-2.2 parts anti-settling agent, 0.2-0.3 parts defoamer, 30-40 parts diluent, 0.6-0.8 parts silane coupling agent and 70-80 parts corrosion inhibitor are mixed evenly and ground at 40-55℃ for 2-3 hours to obtain a slurry. After the slurry is matured for 0.5-1 hour, it is passed through a 300-mesh sieve to obtain the primer. The corrosion resist comprises zinc powder, aluminum powder, and iron phosphorus powder, in a mass ratio of m. 锌 ∶m 铝 ∶m 磷铁粉 =1∶1.3~2∶0.05~0.1; The primer baking process includes: placing the workpiece coated with primer into a heating furnace, introducing a baking protective gas into the furnace, and starting to heat up after 5-8 minutes of gas introduction. The heating method is as follows: Heat the workpiece coated with primer from room temperature to 100°C at a heating rate of 3-5°C / min and hold for 5-10 minutes; then heat the workpiece from 100°C to 200-240°C at a heating rate of 1-2°C / min and hold for 0.5-1 hour; after baking, stop heating and cool the workpiece and the furnace together to 80-100°C, then remove the workpiece and let it cool naturally to room temperature to obtain the primer-baked workpiece. The baking protective gas includes nitrogen and oxygen, with the oxygen content being 5-8% vol of the baking protective gas content.

2. The workpiece surface treatment method according to claim 1, characterized in that, The total thickness of the primer and topcoat sprayed on the workpiece after drying is 20~30μm; The thickness ratio of the primer layer to the topcoat layer is 1:1~2.

3. The workpiece surface treatment method according to claim 1, characterized in that, The topcoat sintering includes: After the workpiece is coated with topcoat, it is placed into a heating furnace. Sintering protective gas is introduced into the furnace, and after 5-8 minutes of gas introduction, the temperature is raised. The heating method is as follows: The workpiece coated with primer is heated from room temperature to 150°C at a heating rate of 3-5°C / min and held for 5-10 minutes. Then, the workpiece is heated from 150°C to 260-300°C at a heating rate of 1-2°C / min and held for 0.5-1.5 hours. After sintering, heating is stopped, and the workpiece and the furnace are cooled together to 80-100°C. The workpiece is then removed, placed naturally, and cooled to room temperature to obtain the finished sintered workpiece.

4. The workpiece surface treatment method according to claim 1 or 3, characterized in that, The topcoat is prepared according to the following method: Acrylic resin and fluorocarbon resin are added to butyl acetate in a ratio of 1:1 to 2, heated to 50 to 60°C and stirred at 1000 rpm for 10 minutes to obtain the base material. Add 10-15% hydrophobic nano-silica, 5-10% polytetrafluoroethylene micro powder, and 1-3% graphene by weight of the base material to the base material, and stir evenly at a speed of 300-500 rpm to obtain a premix. Mix the premixed material and the topcoat curing agent at a weight ratio of 1:0.2~0.3, and cure for 20~30 minutes to obtain the topcoat.

5. The workpiece surface treatment method according to claim 1, characterized in that, The abrasive used in the sandblasting process is one or more of the following: corundum, copper ore sand, quartz sand, iron sand, and sea sand. The abrasive is sprayed onto the workpiece surface using compressed air at a pressure of 0.4~0.6MPa.

6. The workpiece surface treatment method according to claim 1, characterized in that, The primer curing agent includes one or more of aliphatic amines, cycloaliphatic amines, aromatic amines, polyamides, acid anhydrides, resins, or tertiary amines; The anti-settling agent includes one or more of polyolefin wax, polyamide wax, castor oil derivatives, or organobentonite. The defoamer includes one or more organic compounds such as silicone oil, alcohol, fatty acid, fatty acid ester, phosphate ester, mineral oil, and amide. The diluent is one or more of the following: turpentine, rosin, toluene, xylene, banana oil, gasoline, and fatty alcohols.

7. A workpiece, formed by the surface treatment method according to any one of claims 1 to 6, characterized in that, The workpiece body (1) is coated with a primer layer (11) and a topcoat layer (12) on its surface; the thickness ratio of the primer layer to the topcoat layer is 1:1~2.

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