WO2022011663A1 - Method for preparing compact wear-resistant coating on low-carbon steel surface - Google Patents

Abstract

Disclosed is a method for preparing a compact wear-resistant coating on the low-carbon steel surface, the method comprising: weighing Si, W, Ti, Al, Cr, Ni, La and Fe element powders at a preset ratio; ball-milling and mixing the weighed powders in a ball mill, and after same are uniformly mixed, drying same, so as to obtain a filler powder; placing the filler powder into a U-shaped steel strip groove; closing an open end of the U-shaped steel strip groove in which the filler powder is placed, and carrying out wire drawing on the closed U-shaped steel strip groove by means of a wire drawing machine, so as to obtain a powder core wire with a preset diameter; removing dirt and rust from the surface of low-carbon steel to be coated to obtain decontaminated low-carbon steel to be coated; spray-coating the powder core wire on the surface of the decontaminated low-carbon steel to be coated by means of a supersonic arc spraying device, so as to form a coating; and re-melting the coating by means of a non-melt tungsten argon arc welding machine to obtain a compact wear-resistant coating. The compact wear-resistant coating obtained by using the above-mentioned preparation method of the present invention has a good compactness.

Description

A kind of preparation method of dense wear-resistant coating on low carbon steel surface technical field

The invention relates to the technical field of metal surface coating, in particular to a preparation method of a compact wear-resistant coating on the surface of low carbon steel.

Background technique

Wear and corrosion are the main forms of failure of metal materials, especially machine parts under working conditions, such as gears, cylinder liners, and crankshafts of various engines. , The performance of high temperature oxidation resistance is an important factor in determining the length of the machine's service life. Therefore, the use of advanced surface strengthening technology to prepare the required wear-resistant coating on the surface of ordinary materials is an effective method to prevent the surface wear of metal materials. This method can significantly improve the service life of parts and save energy materials and energy.

Thermal spraying technology is one of the common surface repair and protection technologies at present. It has the advantages of high production efficiency, simple operation, good economic benefits, and high material utilization rate. There are many types of thermal spraying technologies, among which supersonic arc spraying is one of the typical technologies of thermal spraying, although supersonic spraying coatings can obtain higher wear resistance. However, there are defects such as pores, cracks, small coating thickness, and poor bonding with the substrate in the spray coating, resulting in poor compactness of the spray coating, and cracking may occur in harsh environments (such as high stress, high temperature and cyclic fatigue). or peeling, limiting its application range.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of a compact wear-resistant coating on the surface of a low carbon steel, so as to solve the problem of poor compactness of the wear-resistant coating prepared by supersonic spraying in the prior art.

For achieving the above object, the present invention provides the following scheme:

A preparation method of a dense wear-resistant coating on a low-carbon steel surface, comprising:

The Si, W, Ti, Al, Cr, Ni, La and Fe elemental powders are weighed according to the preset ratio; the preset ratio is: the Si is 8.5-10.5wt.%, and the W is 6.5 ～8.5wt.%, the Ti is 4.5～7.5wt.%, the Al is 2.5～4.5wt.%, the Cr is 12～20wt.%, the Ni is 5.5～10.5wt.%, so the The La is 1-2% wt.%, and the balance is the Fe;

The weighed powder is ball-milled and mixed in a ball mill, and then dried to obtain a filling powder;

The filling powder is placed in a U-shaped steel strip groove; the U-shaped steel strip groove is made of cold-rolled strip steel;

closing the open end of the U-shaped steel strip groove filled with powder, and using a wire drawing machine to draw the closed U-shaped steel strip groove to obtain a powder core wire with a preset diameter;

The rust on the surface of the low carbon steel to be coated is removed to obtain the decontaminated low carbon steel to be coated;

Use supersonic arc spraying equipment to spray the powder core wire on the surface of the decontamination to be coated low carbon steel to form a coating;

The coating is remelted by a non-melting tungsten argon arc machine to obtain a dense wear-resistant coating.

Optionally, the mixing time of the ball milling is 4-6 hours, the drying temperature is 120-150° C., and the drying time is 1-2 hours.

Optionally, the ball mill is a planetary ball mill.

Optionally, the weight ratio of the filling powder to the U-shaped steel strip groove is (0.4-0.6):1.

Optionally, the wire drawing speed of the wire drawing machine is 160-220 mm/s, and the preset diameter of the powder core wire material is 2 mm.

Optionally, the rust on the surface of the low carbon steel to be coated is removed to obtain the decontaminated low carbon steel to be coated, which specifically includes:

The 14-25 mesh brown corundum is used for sand blasting under the air pressure of 0.7MPa to remove the rust on the surface of the low carbon steel to be coated, and the decontaminated low carbon steel to be coated is obtained.

Optionally, the parameters of the supersonic arc spraying equipment in spraying are: the spraying voltage of the supersonic arc spraying equipment is 25-30V, the spraying current of the supersonic arc spraying equipment is 150-180A, and the spraying air pressure of the supersonic arc spraying equipment. 0.7～1.2MPa, the spraying distance of the supersonic arc spraying equipment is 180～220mm, the wire feeding speed of the supersonic arc spraying equipment is 78～85cm/min, the moving speed of the spray gun is 12～18mm/s, and the spraying thickness is 1.5mm～2.5mm.

Optionally, the parameters of the non-melting tungsten argon arc machine in remelting are: remelting current 100-150A, remelting voltage 18-24V, remelting speed 100-150mm/min, argon gas flow 8- 12L/min.

Optionally, it is characterized in that, the ball milling mixing time is 5h, the drying temperature is 130°C, and the drying time is 1.5h.

Optionally, it is characterized in that the weight ratio of the filling powder to the U-shaped steel strip groove is 0.5:1.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The invention provides a method for preparing a dense wear-resistant coating on the surface of low carbon steel. The element powder is weighed according to a preset ratio, the weighed powder is ball-milled, mixed, dried, and then placed on a U-shaped steel belt. In the tank, the wire drawing machine is used to draw the powder core wire; the supersonic arc spraying equipment is used to spray the prepared powder core wire to the treated low carbon steel surface to form a spray coating, and finally the spray coating is carried out by argon arc remelting. The coating is remelted to obtain a dense wear-resistant coating. The preparation method of the invention is simple, the prepared dense wear-resistant coating has a certain thickness and dense structure, can realize automatic production, and has low cost, and provides a new way for supersonic spraying to prepare the wear-resistant coating.

Instruction drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is the flow chart of the preparation method of a kind of low carbon steel surface dense wear-resistant coating provided by the first embodiment of the present invention;

Fig. 2 is the metallographic micrograph of the dense wear-resistant coating prepared by the second embodiment of the present invention;

Fig. 3 is the metallographic micrograph of the dense wear-resistant coating prepared by Example 3 of the present invention;

Fig. 4 is the microhardness diagram of the dense wear-resistant coating prepared according to the third embodiment of the present invention;

FIG. 5 is a graph of relative wear resistance of the prepared dense wear-resistant coating provided in Example 3 of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a preparation method of a compact wear-resistant coating on the surface of a low carbon steel, so as to solve the problem of poor compactness of the wear-resistant coating prepared by supersonic spraying in the prior art.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1

1 is a flowchart of a method for preparing a dense wear-resistant coating on a low-carbon steel surface according to Embodiment 1 of the present invention. As shown in FIG. 1 , a preparation method of a dense and wear-resistant coating on a low-carbon steel surface of the present invention Methods include:

S101, weighing Si, W, Ti, Al, Cr, Ni, La and Fe elemental powders according to a preset ratio; the preset ratio is: the Si is 8.5-10.5wt.%, the W is 6.5-8.5wt.%, the Ti is 4.5-7.5wt.%, the Al is 2.5-4.5wt.%, the Cr is 12-20wt.%, and the Ni is 5.5-10.5wt.% , the La is 1-2% wt.%, and the balance is the Fe.

S102, the weighed powder is ball-milled and mixed in a ball mill, and the mixed powder is uniformly dried to obtain a filling powder. Specifically, the weighed powder is placed in a planetary ball mill, and ball-milled and mixed at room temperature for 4-6 hours. After mixing, drying is performed at a temperature of 120-150° C. for 1-2 hours to obtain the filling powder.

S103, placing the filling powder in a U-shaped steel strip groove; the U-shaped steel strip groove is made of cold-rolled strip steel. Specifically, cold-rolled strip steel is selected as the coating layer of the powder core wire, and the filling powder is added into the U-shaped steel strip groove, and the weight ratio of the filling powder to the U-shaped steel strip groove is (0.4-0.6 ):1.

S104 , closing the open end of the U-shaped steel belt groove filled with powder, and drawing the closed U-shaped steel belt groove with a wire drawing machine to obtain a powder core wire with a preset diameter. Specifically, the U-shaped steel belt groove covered with the filling powder is closed, and it is drawn into a tubular welding wire at a speed of 160-220 mm/s through a wire drawing die on a wire drawing machine to obtain a powder core wire with a preset diameter of 2.0 mm. .

S105, removing the dirt and rust on the surface of the low carbon steel to be coated to obtain the decontaminated low carbon steel to be coated. Specifically, 14-25 mesh brown corundum is used for sand blasting under the air pressure of 0.7 MPa to remove the rust on the surface of the low carbon steel to be coated, so as to obtain the decontaminated low carbon steel to be coated.

S106, using supersonic arc spraying equipment to spray the powder core wire on the surface of the decontamination to-be-coated mild steel to form a coating.

Specifically, the prepared powder core wire is sprayed onto the surface of the treated mild steel by using a supersonic arc spraying equipment to form a coating. Among them, the parameters of the spraying process are the spraying voltage of the supersonic arc spraying equipment of 25 to 30V, the spraying current of the supersonic arc spraying equipment of 150 to 180A, the spraying pressure of the The spraying distance is 180-220mm, the wire feeding speed of the supersonic arc spraying equipment is 78-85cm/min, the moving speed of the spray gun is 12-18mm/s, and the spraying thickness is 1.5mm-2.5mm.

S107, the coating is remelted by using a non-melting tungsten argon arc machine to obtain a wear-resistant coating. Specifically, a non-melting electrode tungsten electrode argon arc machine is used to remelt the sprayed coating to obtain a wear-resistant coating. Among them, the parameters of the argon arc remelting process are: remelting current 100-150A, remelting voltage 18-24V, remelting speed 100-150mm/min, and argon flow rate 8-12L/min.

Preferably, the ball milling mixing time is 5h, the drying temperature is 130°C, and the drying time is 1.5h.

Preferably, the weight ratio of the filling powder to the U-shaped steel strip groove is 0.5:1.

Preferably, the wire drawing speed of the wire drawing machine is 200 mm/s.

Preferably, the parameters of the supersonic arc spraying equipment in spraying are: the spraying voltage of the supersonic arc spraying equipment is 28V, the spraying current of the supersonic arc spraying equipment is 160A, the spraying air pressure of the supersonic arc spraying equipment is 1.0MPa, the The spraying distance of the arc spraying equipment is 190mm, the wire feeding speed of the supersonic arc spraying equipment is 80cm/min, and the moving speed of the spray gun is 15mm/s.

Preferably, the parameters of the non-melting tungsten argon arc machine in remelting are: remelting current 120A, remelting voltage 20V, remelting speed 120mm/min, and argon flow rate 10L/min.

Embodiment 2

In order to achieve the above object of the present invention, the present invention provides Embodiment 2. In the method for preparing a dense wear-resistant coating on a low-carbon steel surface in this embodiment, the low-carbon steel is Q235 steel. The preparation method includes the preparation of powder core wire material and the preparation of wear-resistant coating. The powder core wire material is sprayed on the surface of carbon steel first, and then argon arc remelting is performed. The powder core wire is prepared by filling powder and U-shaped steel belt groove, and the weight percentage of the filling powder is: 9.5wt.% Si, 7wt.% W, 5.5wt.% Ti, 3wt.% Al, 15% wt. % Cr, 7.5 wt. % Ni, 1% wt. % La, the balance is Fe, the diameter of the core wire is 2.0 mm, and the filling rate is 42%.

A preparation method of a compact wear-resistant coating on a low-carbon steel surface of the present invention comprises the following steps:

In step 201, the powder is weighed according to the above proportion, and the weighed powder is placed in a planetary ball mill for ball-milling and mixing at room temperature for 5 hours;

Step 202 , selecting cold-rolled strip steel as the coating layer of the powder core wire, adding filling powder into the U-shaped steel strip groove, and the weight ratio of the filling powder to the U-shaped steel strip groove is 0.5:1.

In step 203, the U-shaped groove covered with the filling powder is closed, and then drawn on a wire drawing machine through a wire drawing die to form a tubular welding wire at a speed of 160-220 mm/s to obtain a powder core wire with a diameter of 2.0 mm.

Step 204, the surface of the Q235 steel is sandblasted with 14-25 mesh brown corundum under a pressure of 0.7 MPa to remove the rust on the surface.

Step 205, the prepared powder core wire is sprayed on the treated Q235 steel surface by using supersonic arc spraying equipment to form a coating; wherein the parameters of the spraying process are spraying current 160A, spraying voltage 28V, spraying air pressure 1.0MPa, spraying distance 190mm, wire feeding speed 80cm/min, spray gun moving speed 15mm/s, spray thickness 2mm.

In step 206, the sprayed coating is remelted by a non-melting tungsten argon arc machine to obtain a dense wear-resistant coating. Among them, argon arc remelting process parameters are remelting current 120A, remelting voltage 20V, remelting speed 120mm/min, and argon gas flow rate 10L/min.

The cross-sectional morphology of the dense wear-resistant coating in this example was analyzed using an Axio Lab.Al analytical grade upright material microscope, and the results are shown in Figure 2. The dense wear-resistant coating prepared in the embodiment of the present invention has a good metallurgical bond with the substrate, no defects such as pores are generated, and the structure is uniformly distributed in a dendritic shape.

Embodiment 3

In order to achieve the above purpose of the present invention, the present invention provides Embodiment 3. In this embodiment, the low-carbon steel is Q235 steel in a method for preparing a dense wear-resistant coating on a low-carbon steel surface. The preparation method includes the preparation of powder core wire material and the preparation of wear-resistant coating. The powder core wire material is sprayed on the surface of carbon steel first, and then argon arc remelting is performed. The powder core wire material is prepared by filling powder and U-shaped steel belt groove, and the weight percentage of the powder core wire material is: 9.5wt.% Si, 7.5wt.% W, 6.5wt.% Ti, 3wt% % Al, 18% wt. % Cr, 8 wt. % Ni, 1.5 wt. % La, the balance is Fe, the diameter of the core wire is 2.0 mm, and the filling rate is 42%.

A preparation method of a compact wear-resistant coating on a low-carbon steel surface of the present invention comprises the following steps:

In step 301, the powder is weighed according to the above proportion, and the weighed powder is placed in a planetary ball mill for ball milling and mixing at room temperature for 5 hours; the mixed powder after ball milling is kept at 130°C for 1.5 hours to obtain a filling powder.

Step 302 , selecting cold-rolled strip steel as the coating layer of the powder core wire, adding filling powder into the U-shaped steel strip groove, and the weight ratio of the filling powder to the U-shaped steel strip groove is 0.5:1.

Step 303 , the U-shaped groove covered with the powder filling is closed, and then drawn into a tubular welding wire at a speed of 160-220 mm/s through a wire drawing die on a wire drawing machine to obtain a powder core wire with a diameter of 2.0 mm.

Step 304, the surface of the Q235 steel is sandblasted with 14-25 mesh brown corundum under a pressure of 0.7 MPa to remove the rust on the surface.

Step 305, the prepared powder core wire is sprayed on the treated Q235 steel surface by using supersonic arc spraying equipment to form a coating; wherein the parameters of the spraying process are spraying current 160A, spraying voltage 28V, spraying air pressure 1.0MPa, spraying distance 190mm, wire feeding speed 80cm/min, spray gun moving speed 15mm/s, spray thickness 2mm.

In step 306, the sprayed coating is remelted using a non-melting tungsten argon arc machine to obtain a dense wear-resistant coating. Among them, argon arc remelting process parameters are remelting current 120A, remelting voltage 20V, remelting speed 120mm/min, and argon gas flow rate 10L/min.

The cross-sectional morphology of the dense wear-resistant coating in this example was analyzed using an Axio Lab.Al analytical grade upright material microscope, and the results are shown in Figure 3. The dense wear-resistant coating prepared in the embodiment of the present invention has a good metallurgical bond with the substrate, no defects such as pores are generated, and the structure is uniformly distributed in a dendritic shape.

The HVST-1000 Vickers hardness tester is used to test the hardness of the dense wear-resistant coating in this example. The test results are: the hardness of the supersonic spray coating is 515HV, and the hardness of the coating after argon arc remelting treatment is 848HV～ 892HV, it can be seen that the hardness of the coating is increased by 1.6 to 1.7 times after argon arc remelting treatment, as shown in Figure 4.

The friction and wear of the dense wear-resistant coating in this example was tested by the MMS-2A friction and wear tester. The test results are: the relative wear resistance after argon arc remelting is 7 times higher than that of the base Q235 steel, which is higher than that of the base Q235 steel. The wear resistance of the HVAC sprayed coating is increased by a factor of 3, and the results are shown in Figure 5.

The above analysis results show that the dense wear-resistant coating prepared by the combination of supersonic arc spraying technology and argon arc remelting has the advantages of high bonding strength, dense structure, no pollution and high production efficiency. And because the powder cost is low, the cost of the dense wear-resistant coating is low.

In order to solve the problems of non-compactness, small thickness and high porosity of the wear-resistant coating prepared by supersonic spraying, the invention provides a preparation method of the dense wear-resistant coating on the surface of low carbon steel, which adopts supersonic arc spraying and argon arc heavy The melt-phase combination method can obtain coatings with high density and high hardness, thereby promoting the application of coatings in wear-resistant environments.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other.

The principles and implementations of the present invention are described herein using specific examples. The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

A method for preparing a dense wear-resistant coating on a low-carbon steel surface, comprising: The Si, W, Ti, Al, Cr, Ni, La and Fe elemental powders are weighed according to the preset ratio; the preset ratio is: the Si is 8.5-10.5wt.%, and the W is 6.5 ～8.5wt.%, the Ti is 4.5～7.5wt.%, the Al is 2.5～4.5wt.%, the Cr is 12～20wt.%, the Ni is 5.5～10.5wt.%, so the The La is 1-2% wt.%, and the balance is the Fe; The weighed powder is ball-milled and mixed in a ball mill, and then dried to obtain a filling powder; The filling powder is placed in a U-shaped steel strip groove; the U-shaped steel strip groove is made of cold-rolled strip steel; closing the open end of the U-shaped steel strip groove filled with powder, and using a wire drawing machine to draw the closed U-shaped steel strip groove to obtain a powder core wire with a preset diameter; The rust on the surface of the low carbon steel to be coated is removed to obtain the decontaminated low carbon steel to be coated; Use supersonic arc spraying equipment to spray the powder core wire on the surface of the decontamination to be coated low carbon steel to form a coating; The coating is remelted by a non-melting tungsten argon arc machine to obtain a dense wear-resistant coating. The method for preparing a dense wear-resistant coating on a low-carbon steel surface according to claim 1, wherein the ball-milling mixing time is 4-6 hours, the drying temperature is 120-150°C, and the drying Drying time is 1-2h. The method for preparing a dense wear-resistant coating on a low-carbon steel surface according to claim 1, wherein the ball mill is a planetary ball mill. The method for preparing a dense wear-resistant coating on a low carbon steel surface according to claim 1, wherein the weight ratio of the filling powder to the U-shaped steel strip groove is (0.4-0.6):1. The method for preparing a dense wear-resistant coating on a low carbon steel surface according to claim 1, wherein the wire drawing speed of the wire drawing machine is 160-220 mm/s, and the preset diameter of the powder core wire is 2 mm . The method for preparing a dense wear-resistant coating on a low-carbon steel surface according to claim 1, wherein the removing the dirt and rust on the surface of the low-carbon steel to be coated to obtain the decontaminated low-carbon steel to be coated, specifically comprising: Use 14-25 mesh brown corundum to carry out sand blasting under the air pressure of 0.7 MPa to remove the dirt and rust on the surface of the low carbon steel to be coated, so as to obtain the decontaminated low carbon steel to be coated. The method for preparing a compact wear-resistant coating on a low carbon steel surface according to claim 1, wherein the parameters of the supersonic arc spraying equipment in spraying are: the spraying voltage of the supersonic arc spraying equipment is 25-30V, The spraying current of the supersonic arc spraying equipment is 150~180A, the spraying pressure of the supersonic arc spraying equipment is 0.7~1.2MPa, the spraying distance of the supersonic arc spraying equipment is 180~220mm, and the wire feeding speed of the supersonic arc spraying equipment is 78~85cm/ min, the moving speed of the spray gun is 12~18mm/s, and the spray thickness is 1.5mm~2.5mm. The method for preparing a dense wear-resistant coating on a low carbon steel surface according to claim 1, wherein the parameters of the non-melting tungsten argon arc machine in remelting are: remelting current 100-150A, remelting current 100-150A The melting voltage is 18-24V, the remelting speed is 100-150mm/min, and the argon gas flow is 8-12L/min. The method for preparing a dense wear-resistant coating on a low-carbon steel surface according to claim 2, characterized in that, the ball-milling mixing time is 5h, the drying temperature is 130°C, and the drying time is is 1.5h. The method for preparing a dense wear-resistant coating on a low carbon steel surface according to claim 4, wherein the weight ratio of the filling powder to the U-shaped steel strip groove is 0.5:1.

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