阅读说明：本技术 一种Cr3C2增强NiCrMoW减摩耐磨耐蚀涂层、制备方法及其应用 (Cr (chromium)3C2Enhanced NiCrMoW antifriction, wear-resistant and corrosion-resistant coating, preparation method and application thereof ) 是由 张世宏 黄付友 薛召露 梁和平 刘侠 钱立宏 杨康 于 2021-06-15 设计创作，主要内容包括：本发明涉及高温防护涂层技术领域,具体涉及一种Cr-3C-2增强NiCrMoW减摩耐磨耐蚀涂层、制备方法及其应用,涂层包括质量百分数为70～85％的金属相NiCrMoW和15～30％的陶瓷增强相Cr-3C-2,通过大气等离子喷涂技术在基体上喷涂得到的涂层,通过控制制备工艺参数在涂层中保留了(4-7)％的孔隙可以储存润滑油,可以大大降低摩擦系数,在保持涂层优异耐磨耐蚀性能的同时,还具有高结合强度。(The invention relates to the technical field of high-temperature protective coatings, in particular to Cr 3 C 2 The coating comprises 70-85% of metal phase NiCrMoW and 15-30% of ceramic reinforcing phase Cr in percentage by mass 3 C 2 The coating obtained by spraying the atmosphere plasma spraying technology on the substrate reserves (4-7)% of pores in the coating by controlling the preparation process parameters, can store lubricating oil, can greatly reduce the friction coefficient, and keeps excellent wear resistance of the coatingCorrosion resistance and high bonding strength.)

1. Cr (chromium)₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is characterized by comprising 70-85% of metal phase NiCrMoW and 15-30% of ceramic reinforcing phase Cr in percentage by mass₃C₂。

2. The Cr of claim 1₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is characterized in that the metal phase NiCrMoW and the ceramic reinforcing phase Cr₃C₂The mass percentages are respectively as follows: NiCrMoW: cr (chromium) component₃C₂＝22.5：77.5。

3. The Cr of claim 1₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is characterized in that the metal phase comprises the following components in percentage by mass: ni: cr: mo: w: 57-65: 15-17: 13-20: 3 to 4.

4. The Cr of claim 1₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is characterized in that the metal phase NiCrMoW comprises gamma-Ni (Cr, Mo), NiCr and Cr₃C₂。

5. The Cr of claim 1₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is characterized in that the porosity of the coating is 4-7%, and the thickness of the coating is 100-200 mu m.

6. The Cr of claim 1₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is characterized in that the particle size of the coating is 30-60 mu m.

7. Cr as claimed in any one of claims 1 to 6₃C₂The preparation method of the reinforced NiCrMoW antifriction and wear-resistant coating is characterized by comprising the following steps：

S1: carrying out sand blasting and coarsening on the matrix;

s2: preparing Cr on the coarsened substrate obtained in the step S1 by adopting an atmospheric plasma spraying technology₃C₂And the reinforced NiCrMoW antifriction and wear-resistant coating.

8. Cr as claimed in claim 7₃C₂The preparation method of the enhanced NiCrMoW antifriction and wear-resistant coating is characterized in that the process parameters of the atmospheric plasma spraying technology in the step S2 are as follows: the current is 580-620A, the voltage is 55-65V, the powder feeding rate is 30-40 g/min, the spraying distance is 65-90 mm, the main air flow Ar gas is 32-42L/min, the linear speed is 550-650 mm/s, and the step pitch is 2-4 mm.

9. Cr as claimed in any one of claims 1 to 6₃C₂The reinforced NiCrMoW antifriction and abrasion-resistant coating is applied to the field of internal combustion engines.

Technical Field

The invention relates to the technical field of high-temperature protective coatings, in particular to Cr₃C₂An enhanced NiCrMoW antifriction, wear-resistant and corrosion-resistant coating, a preparation method and application thereof.

Background

The diesel engine is one of the most widely applied mechanical devices at present, and the internal friction pair is numerous and the movement form is complex. Particularly, as the number of global automobiles, engineering machinery, military equipment and the like is rapidly increased, the problem of frictional wear of a diesel engine is more and more prominent as a main power source. Climate change and energy issues make it imperative to improve vehicle fuel economy. Therefore, higher requirements are put forward on the fuel efficiency, energy conservation and emission reduction of the diesel engine. The development height of the diesel vehicle industry in China is determined by mastering key technologies of high efficiency, energy conservation, emission reduction, light weight and the like of an advanced diesel engine. The cylinder sleeve is a cylindrical part embedded in the cylinder body of the engine, and forms a combustion chamber of the engine together with the cylinder cover, the piston and the piston ring. The prior research shows that the piston ring-cylinder sleeve is the most important friction pair in the engine, and the energy consumed by friction accounts for about 60 percent of the total energy consumed by friction. The working environment of a combustion chamber in a diesel engine is extremely severe, and a cylinder sleeve not only bears the impact of high-temperature and high-pressure fuel gas, but also is subjected to friction generated by reciprocating motion of a piston ring, so that the cylinder sleeve is easy to generate abrasive wear, corrosive wear and adhesive wear, and the cylinder sleeve is required to have good performances such as wear resistance, corrosion resistance, low friction coefficient, high mechanical strength and the like.

The thermal spraying technology is the most widely applied preparation method of the cylinder inner wall coating, and the wear resistance, corrosion resistance and other properties of the cylinder inner wall coating can be obviously improved on the basis of not changing the shape and the properties of a base material. Meanwhile, the light weight of the automobile becomes a development trend of the automobile industry, and the research and development of reliable coating on the inner wall of the cylinder to replace a cast iron cylinder sleeve embedded in an aluminum alloy cylinder body becomes a trend. Therefore, the research and development of the antifriction, wear-resistant and corrosion-resistant coating with high bonding strength and applied to the field of internal combustion engines are urgently needed to improve the fuel efficiency of the engines and realize the light weight, so that the purposes of energy conservation and emission reduction are achieved.

In view of the above-mentioned drawbacks, the inventors of the present invention have finally obtained the present invention through a long period of research and practice.

Disclosure of Invention

The invention aims to solve the problem of how to prepare a coating with high bonding strength, friction reduction, wear resistance and corrosion resistance applied to the field of internal combustion engines, and provides Cr₃C₂An enhanced NiCrMoW antifriction, wear-resistant and corrosion-resistant coating, a preparation method and application thereof.

In order to achieve the purpose, the invention discloses Cr₃C₂The coating comprises 70-85% of metal phase NiCrMoW and 15-30% of ceramic reinforcing phase Cr in percentage by mass₃C₂。

Preferably, the metal phase NiCrMoW and the ceramic reinforcing phase Cr are₃C₂The mass percentages are respectively as follows: NiCrMoW: cr (chromium) component₃C₂＝22.5：77.5。

The metal phase comprises the following components in percentage by mass: ni: cr: mo: w: 57-65: 15-17: 13-20: 3 to 4.

The metal phase NiCrMoW comprises gamma-Ni (Cr, Mo), NiCr and Cr₃C₂。

The porosity of the coating is 4-7%, and the thickness of the coating is 100-200 mu m.

The particle size of the coating is 30-60 mu m.

The invention also discloses the Cr₃C₂The preparation method of the reinforced NiCrMoW antifriction and wear-resistant coating comprises the following steps:

s1: carrying out sand blasting and coarsening on the matrix;

s2: preparing Cr on the coarsened substrate obtained in the step S1 by adopting an atmospheric plasma spraying technology₃C₂And the reinforced NiCrMoW antifriction and wear-resistant coating.

The process parameters of the atmospheric plasma spraying technology in the step S2 are as follows: the current is 580-620A, the voltage is 55-65V, the powder feeding rate is 30-40 g/min, the spraying distance is 65-90 mm, the main air flow Ar gas is 32-42L/min, the linear speed is 550-650 mm/s, and the step pitch is 2-4 mm.

The invention also discloses the Cr₃C₂The reinforced NiCrMoW antifriction and wear-resistant coating is applied to the field of internal combustion engines.

Compared with the prior art, the invention has the beneficial effects that: the invention adopts the air plasma spraying technology to prepare Cr on the roughened inner wall surface in the cylinder sleeve₃C₂The NiCrMoW coating is enhanced to improve the wear resistance and corrosion resistance of the cylinder sleeve, and simultaneously, (4-7)% of pores are reserved in the coating by controlling preparation process parameters to store lubricating oil, so that the friction coefficient can be greatly reduced. The invention adopts corrosion-resistant NiCrMoW with the mass fraction up to (70-80)% as the metal phase, and Cr₃C₂The content of the reinforcing phase is small, so that the coating has high bonding strength, and the coating has high bonding strength while maintaining excellent wear resistance and corrosion resistance; cr (chromium) component₃C₂The metal phase NiCrMoW of the reinforced NiCrMoW coating contains a large amount of Mo element, and the content of the Mo element is increased, so that the acid corrosion resistance and the wear resistance of the coating are improved. In addition, Cr₃C₂The high-hardness and wear-resisting performance of the alloy can be kept well at high temperature, and Cr is adopted in the invention₃C₂As a reinforcing phase, the wear resistance of this coating can be improved. Therefore, the coating of the invention not only has high bonding strength, but also has excellent antifriction, wear-resistant and corrosion-resistant performances, compared with the prior FeCrBSi coating, the Cr coating of the invention has high bonding strength and excellent antifriction, wear-resistant and corrosion-resistant performances₃C₂The friction coefficient of the enhanced NiCrMoW antifriction and abrasion-resistant coating at room temperature and under lubricating oil is reduced by 10 percent compared with FeCrBSi, the abrasion rate at 700 ℃ is reduced by 84 percent compared with the FeCrBSi coating, and the enhanced NiCrMoW antifriction and abrasion-resistant coating has excellent oxidation resistance and Na resistance at 700 ℃ simultaneously₂SO₄Corrosion performance.

Drawings

FIG. 1 is an atmospheric plasma spray of Cr₃C₂The structural schematic diagram of the reinforced NiCrMoW coating;

FIG. 2 shows different Cr layers sprayed by atmospheric plasma₃C₂Content of NiCrMoW-Cr₃C₂XRD pattern of the coating;

FIG. 3 is an atmospheric plasma spray NiCrMoW-15Cr₃C₂Coating at 700 deg.C-Na₂SO₄Lower corrosion oxidation kinetics curve;

FIG. 4 shows NiCrMoW-22.5Cr₃C₂A surface topography of the agglomerated sintering powder spray powder;

FIG. 5 is an atmospheric plasma spray NiCrMoW-22.5Cr₃C₂And the coefficient of friction of the FeCrBSi coating at room temperature-lubricating oil;

FIG. 6 shows different Cr layers sprayed by atmospheric plasma₃C₂Content of NiCrMoW-Cr₃C₂The wear rate of the coating at 300 ℃.

Detailed Description

The above and further features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.

Example 1

Preparing NiCrMoW-15Cr on the surface of a vermicular graphite cast iron matrix by adopting an atmospheric plasma spraying technology₃C₂(wt.%) coating, wherein the metallic phase NiCrMoW comprises, in mass%: 63.3Ni-16Cr-17 Mo-3.7W;

preparing NiCrMoW-15Cr with the thickness of 150 mu m on the surface of the cylinder sleeve substrate subjected to sand blasting or electric spark coarsening by adopting an atmospheric plasma spraying technology₃C₂The coating comprises the following process parameters: the current is 600A, the voltage is 60V, the powder feeding rate is 30g/min, the spraying distance is 65mm, the main gas flow Ar gas is 40L/min, the linear velocity is 600mm/s, and the step pitch is 2 mm;

the plasma spraying NiCrMoW-15Cr can be known by XRD phase analysis₃C₂(wt.%) the coating mainly contains gamma-Ni (Cr, Mo), and Cr₃C₂And a small amount of NiCr phase (as shown in fig. 2). The average bonding strength of the coating is 60MPa and the porosity is 4 percent according to the standard of GB/T8642-2002 determination of the tensile bonding strength of thermal spraying through tensile test. The coating is 700-Na₂SO₄The lower corrosion oxidation kinetics is shown in FIG. 3, from which it can be seen that the coating is applied after 10h oxidationThe weight gain of the layer is almost unchanged, exhibiting good high temperature oxidation resistance.

Example 2

Preparing NiCrMoW-22.5Cr on the surface of a vermicular cast iron matrix by adopting an atmospheric plasma spraying technology₃C₂(wt.%) coating, wherein the metallic phase NiCrMoW comprises, in mass%: 64Ni-17Cr-15.4 Mo-3.6W;

preparing NiCrMoW-22.5Cr with the thickness of 200 mu m on the surface of the cylinder sleeve substrate subjected to sand blasting or electric spark coarsening by adopting an atmospheric plasma spraying technology₃C₂The coating comprises the following process parameters: the current is 580A, the voltage is 65V, the powder feeding rate is 35g/min, the spraying distance is 80mm, the main gas flow Ar gas is 42L/min, the linear velocity is 600mm/s, and the step pitch is 3 mm;

FIG. 4 shows NiCrMoW-22.5Cr₃C₂The surface topography of the agglomerated sintering powder spray coating powder can be seen, and NiCrMoW-22.5Cr can be seen from the surface topography₃C₂The spray powder is spherical and has a particle size of 45-55 μm. The plasma spraying NiCrMoW-22.5Cr can be known by XRD phase analysis₃C₂(wt.%) the coating mainly contains gamma-Ni (Cr, Mo), and Cr₃C₂And a small amount of NiCr phase (as shown in fig. 2). The average bonding strength of the coating is tested by a tensile test according to the standard GB/T8642-2002 determination of the tensile bonding strength of thermal spraying, and the porosity is 4.72%. The friction coefficient of the coating at room temperature and lubricating oil is only 0.075 (as shown in figure 5), and is reduced by nearly 50% compared with the friction coefficient of a plasma spraying FeCrBSi coating at room temperature and lubricating oil under the same condition.

The wear rate under 300 ℃ dry friction is 2.06X 10^-5mm³In Cr of₃C₂The doping concentration is minimal between (7.5-37.5)% as shown in fig. 6.

Example 3

Preparing NiCrMoW-30Cr on the surface of a vermicular graphite cast iron matrix by adopting an atmospheric plasma spraying technology₃C₂(wt.%) coating, wherein the metallic phase NiCrMoW comprises, in mass%: 64Ni-17Cr-15.4 Mo-3.6W;

cylinder sleeve roughened by sand blasting or electric spark by adopting atmospheric plasma spraying technologyPreparing NiCrMoW-30Cr with the thickness of 200 mu m on the surface of the substrate₃C₂The coating comprises the following process parameters: the current is 600A, the voltage is 65V, the powder feeding rate is 35g/min, the spraying distance is 70mm, the main gas flow Ar gas is 35L/min, the linear velocity is 600mm/s, and the step pitch is 3 mm;

the plasma spraying NiCrMoW-30Cr can be known by XRD phase analysis₃C₂(wt.%) the coating mainly contains gamma-Ni (Cr, Mo), and Cr₃C₂And a small amount of NiCr phase (as shown in fig. 2). The average bonding strength of the coating is 58MPa according to the standard of GB/T8642-2002 determination of tensile bonding strength of thermal spraying through tensile test, the porosity is 5.61%, and the wear rate under the condition of dry friction at 300 ℃ is 2.19 multiplied by 10^-5mm³N · m; and the coating has excellent oxidation resistance at 700 ℃.

Comparative example 1

Different from the example 2, the spraying powder adopted by the comparative example is FeCrBSi powder, and the mass percentages of the main components are as follows: (2-30) Cr, (1.5-2.5) B, (2-3) Si and the balance of Fe, and the steps for preparing FeCrBSi coating by the following plasma spraying are the same.

And preparing a FeCrBSi coating on the surface of the vermicular graphite cast iron matrix by adopting an atmospheric plasma spraying technology. Preparing NiCrMoW-22.5Cr with the thickness of 200 mu m on the surface of the cylinder sleeve substrate subjected to sand blasting or electric spark coarsening by adopting an atmospheric plasma spraying technology₃C₂The coating comprises the following process parameters: the current is 580A, the voltage is 65V, the powder feeding rate is 35g/min, the spraying distance is 80mm, the main gas flow Ar gas is 42L/min, the linear velocity is 600mm/s, and the step pitch is 3 mm;

FIG. 5 shows that the friction coefficient of FeCrBSi coating prepared by plasma spraying at room temperature and lubricating oil is only 0.1146 (as shown in FIG. 5), which is higher than that of NiCrMoW-22.5Cr coating prepared by plasma spraying under the same conditions₃C₂The friction coefficient of the coating at room temperature under lubricating oil is as high as 50%.

The foregoing is merely a preferred embodiment of the invention, which is intended to be illustrative and not limiting. It will be understood by those skilled in the art that various changes, modifications and equivalents may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.