Corrosion-resistant multilayer composite coating and method of making same

Abstract

The application discloses a kind of corrosion-resistant multilayer composite coating, belong to surface corrosion protection technical field, including sequentially arranged primer layer, intermediate coating and surface coating, the primer layer is FeCrAl coating, the intermediate coating includes intermediate coating one and intermediate coating two, the intermediate coating is FeCrAlY coating, FeCrAlTi coating, FeCrAlZr coating, FeCrAlSi coating in any two kinds, the surface coating is FeCrAlYSi coating, FeCrAlYTi coating, FeCrAlYZr coating, FeCrAlSiZr coating, FeCrAlSiTi coating, FeCrAlTiZr coating in any one kind;The application corrosion-resistant multilayer composite coating and substrate binding force are good, excellent thermal shock resistance, coating has excellent lead / lead bismuth alloy corrosion resistance, and preparation method is simple.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of surface corrosion protection technology, in particular to a kind of corrosion-resistant multilayer composite coating and preparation method thereof. BACKGROUND

[0002] In order to improve nuclear safety and the economy of reactor, six advanced fourth generation reactors are proposed, among which lead-cooled fast reactor (LFR) is considered as one of the most promising fourth generation reactors due to its high thermal cycle efficiency, high power density and inherent safety. Lead and its alloys (LBE) are considered as ideal coolants due to their high thermal conductivity, low melting point, high boiling point and excellent neutron performance. However, a large number of studies have shown that lead / lead bismuth alloy at high temperature will cause serious corrosion to reactor structural materials, especially fuel cladding tubes, resulting in the formation of thick oxide layer on the surface of structural materials, which will periodically peel off under the scouring action of flowing lead / lead bismuth, and the peeled-off corrosion products may eventually block the pipes in the reactor. In addition, the formation of thick oxide layer on the surface of cladding tube will also seriously affect the heat transfer performance of cladding tube wall. Therefore, it is particularly important to slow down the corrosion of structural materials in reactor at high temperature.

[0003] Existing corrosion mitigation strategies include the addition of corrosion inhibitors in lead / lead bismuth alloy, the design of new structural materials and the surface modification of structural materials. Among these corrosion mitigation strategies, the surface modification technology of structural materials, especially the deposition of corrosion-resistant coating on the surface of structural materials, has attracted more and more researchers to invest in it.

[0004] In the prior art, Al2O3, TiO2, AlTiN, TiSiN, FeAl, HEA and FeCrAl-based coatings have been widely studied, but the adhesion between the coating and the substrate, the thermal shock resistance and the corrosion resistance to lead / lead bismuth alloy still need to be improved. SUMMARY

[0005] The present application is to solve the technical problem of the adhesion between the existing corrosion-resistant coating on the surface of structural materials and the substrate, the thermal shock resistance and the corrosion resistance to lead / lead bismuth alloy, and aims to provide a kind of corrosion-resistant multilayer composite coating and preparation method thereof. The corrosion-resistant multilayer composite coating has good adhesion to the substrate, excellent thermal shock resistance, and the coating has excellent corrosion resistance to lead / lead bismuth alloy, and the preparation method is simple.

[0006] The present application is realized by the following technical scheme:

[0007] A kind of corrosion-resistant multilayer composite coating, comprising bottom coating, intermediate coating and surface coating arranged in sequence;

[0008] The bottom coating is a FeCrAl coating;

[0009] The intermediate coating comprises intermediate coating one and intermediate coating two, and the intermediate coating is any two of FeCrAlY coating, FeCrAlTi coating, FeCrAlZr coating and FeCrAlSi coating.

[0010] The surface coating is any one of FeCrAlYSi coating, FeCrAlYTi coating, FeCrAlYZr coating, FeCrAlSiZr coating, FeCrAlSiTi coating and FeCrAlTiZr coating.

[0011] As a further technical scheme of the application, the thickness of the corrosion-resistant multilayer composite coating is 1-30 microns.

[0012] The application also provides a preparation method of the corrosion-resistant multilayer composite coating, comprising the following steps:

[0013] S1: after polishing and polishing the substrate, ultrasonic cleaning, drying for standby;

[0014] S2: fixing the cleaned substrate on the magnetron sputtering sample table, installing FeCrAl alloy target and elemental target, and the elemental target is any two of Si, Zr, Y and Ti;

[0015] S3: using single target, double target and three target co-sputtering respectively, sequentially obtaining the bottom coating FeCrAl coating, the intermediate coating and the surface coating on the substrate surface, and the intermediate coating comprises intermediate coating one and intermediate coating two.

[0016] As a further technical scheme of the application, S1 is specifically:

[0017] After polishing the substrate with sandpaper, polishing to mirror surface with diamond polishing paste, and then ultrasonic cleaning with acetone and alcohol for 20 minutes and drying for standby.

[0018] As a further technical scheme of the application, the sandpaper is water-based SiC sandpaper with a roughness of 400-5000 mesh, and the diamond polishing paste is water-soluble diamond polishing paste.

[0019] As a further technical scheme of the application, the preparation method of the bottom coating is:

[0020] Opening the mechanical pump, molecular pump and elemental target shutter, closing the FeCrAl alloy target shutter, heating, and when the vacuum degree of the cavity reaches 10 -3 ~ 10 -4 Pa, introducing Ar gas and starting sputtering, and obtaining the bottom coating FeCrAl coating under the conditions of sputtering pressure of 0.5-1.0 Pa, pulse bias of -50-200 V, sputtering power of 100-500 W and sputtering time of 1-5 h.

[0021] As a further technical solution of the present application, the preparation method of the intermediate coating is:

[0022] After the single-target sputtering is completed, the shutters of any one of the single-element targets are closed, the shutter of the FeCrAl target is kept closed, the shutters of the remaining targets are opened, Ar gas is introduced and glow sputtering is started, the sputtering pressure is 0.5-1.0 Pa, the pulse bias is -50-200 V, the sputtering power of the FeCrAl alloy target is 100-500 W, the sputtering power of the single-element target is 30-100 W, the sputtering time is 1-5 h, and the intermediate coating one is obtained.

[0023] The above steps are repeated to obtain the intermediate coating two.

[0024] As a further technical solution of the present application, the preparation method of the surface coating is:

[0025] After the double-target sputtering is completed, the shutters of two single-element targets among the single-element targets are closed, the shutter of the FeCrAl target is kept closed, Ar gas is introduced and glow sputtering is started, the sputtering pressure is 0.5-1.0 Pa, the pulse bias is -50-200 V, the sputtering power of the FeCrAl alloy target is 100-500 W, the sputtering power of the single-element target is 30-100 W, the sputtering time is 1-5 h, and the surface coating is obtained.

[0026] As a further technical solution of the present application, the base body is stainless steel or ferritic / martensitic stainless steel. The stainless steel is 316L, and the ferritic / martensitic stainless steel is any one of T91, SIMP, CLAM and CLF-1.

[0027] As a further technical solution of the present application, in the FeCrAl alloy target, the content of Cr is 9-20 wt%, the content of Al is 4-15 wt%, and the rest is Fe.

[0028] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0029] 1. The corrosion-resistant multilayer composite coating of the present application has good adhesion to the base body, excellent thermal shock resistance, and excellent lead / lead-bismuth alloy corrosion resistance.

[0030] 2. The composite coating of the present application is prepared by a conventional magnetron sputtering method, which is simple and mature. By controlling the sputtering time of different coating systems, single-layer coatings of different thicknesses and multilayer coatings of certain thicknesses can be prepared. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0032] Figure 1 It is a structural schematic diagram of the present application;

[0033] Figure 2 It is a substrate bonding strength test diagram of the corrosion-resistant multilayer composite coating of Example 1;

[0034] Figure 3 It is a substrate bonding strength test diagram of the corrosion-resistant multilayer composite coating of the comparative example;

[0035] Figure 4 It is a coating surface morphology diagram of the corrosion-resistant multilayer composite coating of Example 1 after 600℃ corrosion test.

[0036] Markings in the drawings and corresponding component names:

[0037] 1-substrate, 2-bottom coating, 3-intermediate coating one, 4-intermediate coating two, 5-surface coating. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application more clear and obvious, the following will further describe the present application in combination with embodiments and drawings. The exemplary embodiments of the present application and their descriptions are only used to explain the present application, and should not be considered as limiting the present application.

[0039] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be practiced without these specific details. In other embodiments, well-known structures, circuits, materials or methods are not specifically described in order to avoid obscuring the present application.

[0040] Example 1

[0041] The present embodiment provides a corrosion-resistant multilayer composite coating, which comprises a bottom coating 2, an intermediate coating one 3, an intermediate coating two 4 and a surface coating 5 arranged on the surface of a substrate 1 in sequence, the bottom coating 2 is a FeCrAl coating, the intermediate coating one 3 is a FeCrAlY coating, the intermediate coating two 4 is a FeCrAlSi coating, and the surface coating 5 is a FeCrAlYSi coating.

[0042] A preparation method of a corrosion-resistant multilayer composite coating, comprising the following steps:

[0043] S1, ferrite / martensite stainless steel (T91) is cut into a disc with a diameter of 10 mm and a thickness of 1.5 mm by using an electric spark wire cutting device;

[0044] S2, the disc obtained in step S1 is polished to a mirror surface by using water-based SiC sandpaper with a mesh size of 400, 600, 800, 1000, 2000, 3000, and 5000 respectively, and then polished by using diamond polishing paste with a mesh size of W3.5-W0.01, and then cleaned by ultrasonic cleaning with acetone and alcohol for 20 minutes and dried for standby use;

[0045] S3, the cleaned sample obtained in step S2 is fixed on a magnetron sputtering sample table for 16 times, and an FeCrAl alloy target (the content of Cr is 15wt%, and the content of Al is 10wt%), a Y target and a Si target are installed; then a mechanical pump, a molecular pump, a Y target shutter, a Si target shutter, heating, a FeCrAl target shutter are opened respectively, the heating temperature is set to 300℃ to improve the adhesion between the coating and the substrate, and after the vacuum degree of the cavity reaches 6.0×10 -4 Pa, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.6 Pa, the pulse bias is-200 V, the sputtering power is 300 W, the sputtering time is 2 h, and the obtained FeCrAl coating has a thickness of about 2 um;

[0046] S4, after the sputtering is completed, the Y target shutter is closed and the Si target shutter is kept open, the FeCrAl target shutter is closed, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.6 Pa, the pulse bias is-200 V, the power of the single target material is controlled individually, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Y target is 50 W, the sputtering time is 3 h, and the obtained FeCrAlY coating has a thickness of about 3 um;

[0047] S5, after the sputtering is completed, the Y target shutter is opened, the Si target shutter is closed and the FeCrAl target shutter is kept closed, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.6 Pa, the pulse bias is-200 V, the power of the single target material is controlled individually, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Si target is 60 W, the sputtering time is 2 h, and the obtained FeCrAlSi coating has a thickness of about 2 um;

[0048] S6, after the sputtering is completed, the Y target shutter is closed, and the Si target and the FeCrAl target shutter are kept closed, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.8 Pa, the pulse bias is-200 V, the power of the single target material is controlled individually, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Si target is 60 W, the sputtering power of the Y target is 50 W, the sputtering time is 4 h, and the obtained FeCrAlYSi coating has a thickness of about 4 um.

[0049] S7, after sputtering, open the Y target, Si target and FeCrAl target shutter respectively; naturally cool the cavity to room temperature and close the molecular pump, mechanical pump, and take out the sample for standby.

[0050] Example 2

[0051] The embodiment provides a corrosion-resistant multilayer composite coating, which comprises a base layer 2, an intermediate layer one 3, an intermediate layer two 4 and a surface layer 5 arranged on the surface of a substrate 1 in sequence, the base layer 2 is a FeCrAl coating layer, the intermediate layer one 3 is a FeCrAlY coating layer, the intermediate layer two 4 is a FeCrAlTi coating layer, and the surface layer 5 is a FeCrAlYTi coating layer.

[0052] A preparation method of a corrosion-resistant multilayer composite coating, comprising the following steps:

[0053] S1, cutting ferrite / martensite stainless steel (T91) into a round piece with a diameter of 10 mm and a thickness of 1.5 mm by using an electric spark wire cutting device;

[0054] S2, polishing the round piece obtained in step S1 by using water-based SiC sandpaper with a granularity of 400, 600, 800, 1000, 2000, 3000 and 5000 respectively, and polishing to a mirror surface by using diamond polishing paste with a granularity of W3.5-W0.01, then ultrasonic cleaning the polished round piece by using acetone and alcohol for 20 minutes and drying for standby;

[0055] S3, fixing the cleaned sample obtained in step S2 on a magnetron sputtering sample table for 16 times, and installing a FeCrAl alloy target (the content of Cr is 15wt%, and the content of Al is 10wt%), a Y target and a Ti target; then starting a mechanical pump, a molecular pump, a Y target shutter, a Ti target shutter, heating and closing a FeCrAl target shutter respectively, setting the heating temperature to 300 DEG C to improve the adhesion between the coating and the substrate, and after the vacuum degree of the cavity reaches 6.0x10 -4 Pa, introducing Ar gas and starting glow sputtering; the sputtering pressure is 0.6 Pa, the pulse bias is-200 V, the sputtering power is 300 W, the sputtering time is 2 h, and the obtained FeCrAl coating layer has a thickness of about 2 um;

[0056] S4, after sputtering, closing the Y target shutter and keeping the Ti target shutter open, closing the FeCrAl target shutter, introducing Ar gas and starting glow sputtering; the sputtering pressure is 0.6 Pa, the pulse bias is-200 V, and the sputtering power of a single target material is controlled individually, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Y target is 50 W, the sputtering time is 3 h, and the obtained FeCrAlY coating layer has a thickness of about 3 um;

[0057] S5, after sputtering, open the Y target shutter, close the Ti target shutter and keep the FeCrAl target shutter closed, introduce Ar gas and glow sputtering; the sputtering pressure is 0.6 Pa, the pulse bias is -200 V, the single target material power is controlled independently, wherein the sputtering power of the FeCrAl alloy target material is 300 W, the sputtering power of the Si target material is 60 W, the sputtering time is 2 h, and the obtained FeCrAlTi coating thickness is about 2 um;

[0058] S6, after sputtering, close the Y target shutter, and keep the Ti target and FeCrAl target shutters closed, introduce Ar gas and glow sputtering; the sputtering pressure is 0.8 Pa, the pulse bias is -200 V, the single target material power is controlled independently, wherein the sputtering power of the FeCrAl alloy target material is 300 W, the sputtering power of the Si target material is 60 W, the sputtering power of the Y target material is 50 W, the sputtering time is 4 h, and the obtained FeCrAlYTi coating thickness is about 4 um;

[0059] S7, after sputtering, open the Y target, Ti target and FeCrAl target shutters respectively; naturally cool the cavity to room temperature and close the molecular pump and mechanical pump, and take out the sample for standby.

[0060] Example 3

[0061] The embodiment provides a kind of corrosion-resistant multilayer composite coating, including sequentially arranged on the surface of substrate 1 bottom coating 2, intermediate coating one 3, intermediate coating two 4 and surface coating 5, the bottom coating 2 is FeCrAl coating, intermediate coating one 3 is FeCrAlY coating, intermediate coating two 4 is FeCrAlZr coating, and surface coating 5 is FeCrAlYZr coating.

[0062] A kind of corrosion-resistant multilayer composite coating preparation method, comprising the following steps:

[0063] S1, ferrite / martensite stainless steel (T91) is cut into round piece with diameter of 10 mm and thickness of 1.5 mm by electric spark wire cutting equipment;

[0064] S2, the round piece obtained in step S1 is polished with 400, 600, 800, 1000, 2000, 3000 and 5000 purpose water-based SiC sandpaper respectively, and is polished to mirror surface with W3.5-W0.01 diamond polishing paste, then the polished round piece is ultrasonically cleaned with acetone and alcohol for 20 minutes and dried for standby;

[0065] S3, the cleaned sample obtained in step S2 is fixed on the magnetron sputtering sample table for 16 times, and FeCrAl alloy target (the content of Cr is 15wt%, and the content of Al is 10wt%), Y target and Zr target are installed; then the mechanical pump, the molecular pump, the Y target shutter, the Zr target shutter, the heating, the FeCrAl target shutter are opened respectively, the heating temperature is set to 300 DEG C to improve the coating and the substrate bonding force, and the cavity is vacuumized to 6.0*10 -4 After 0.6 Pa, the pulse bias is -200 V, the sputtering power is 300 W, the sputtering time is 2 h, and the obtained FeCrAl coating thickness is about 2 um.

[0066] S4, after sputtering, the Y target shutter is closed and the Zr target shutter is kept open, the FeCrAl target shutter is closed, Ar gas is introduced and sputtering is started; the sputtering pressure is 0.6 Pa, the pulse bias is -200 V, and the single target power is controlled independently, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Y target is 50 W, the sputtering time is 3 h, and the obtained FeCrAlY coating thickness is about 3 um.

[0067] S5, after sputtering, the Y target shutter is opened, the Zr target shutter is closed and the FeCrAl target shutter is kept closed, Ar gas is introduced and sputtering is started; the sputtering pressure is 0.6 Pa, the pulse bias is -200 V, and the single target power is controlled independently, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Si target is 60 W, the sputtering time is 2 h, and the obtained FeCrAlZr coating thickness is about 2 um.

[0068] S6, after sputtering, the Y target shutter is closed, and the Zr target and the FeCrAl target shutter are kept closed, Ar gas is introduced and sputtering is started; the sputtering pressure is 0.8 Pa, the pulse bias is -200 V, and the single target power is controlled independently, wherein the sputtering power of the FeCrAl alloy target is 300 W, the sputtering power of the Si target is 60 W, the sputtering power of the Y target is 50 W, the sputtering time is 4 h, and the obtained FeCrAlYZr coating thickness is about 4 um.

[0069] S7, after sputtering, the Y target, the Zr target and the FeCrAl target shutter are opened respectively; the cavity is naturally cooled to room temperature and the molecular pump and the mechanical pump are closed, and the sample is taken out for standby.

[0070] Example 4

[0071] The embodiment provides a kind of corrosion-resistant multilayer composite coating, including sequentially arranged in the surface of base 1 bottom coating 2, intermediate coating one 3, intermediate coating two 4 and surface coating 5, the bottom coating 2 is FeCrAl coating, intermediate coating one 3 is FeCrAlZr coating, intermediate coating two 4 is FeCrAlSi coating, and surface coating 5 is FeCrAlSiZr coating.

[0072] A kind of corrosion-resistant multilayer composite coating preparation method, comprising the following steps:

[0073] S1, ferrite / martensite stainless steel (T91) is cut into round piece with diameter of 10mm and thickness of 1.5mm by spark erosion wire cutting equipment;

[0074] S2, the round piece obtained in step S1 is respectively polished with 400, 600, 800, 1000, 2000, 3000, 5000 purpose water-based SiC sandpaper, and is respectively polished to mirror surface with W3.5-W0.01 diamond polishing paste, then the polished round piece is ultrasonically cleaned with acetone, alcohol for 20 minutes and dried for standby use;

[0075] S3, the sample cleaned in step S2 is fixed on magnetron sputtering sample table for 16 times, and FeCrAl alloy target (the content of Cr is 15wt%, and the content of Al is 10wt%), Zr target and Si target are installed;Then respectively open mechanical pump, molecular pump, Zr target shutter, Si target shutter, heating, close FeCrAl target block, and the heating temperature is set to 300 DEG C to improve the adhesion of coating and substrate, after the cavity vacuum degree reaches 6.0x10 -4 Pa, Ar gas is introduced and glow sputtering is started;Sputtering pressure is 0.6Pa, pulse bias is-200V, sputtering power is 300W, sputtering time is 2h, and the obtained FeCrAl coating thickness is about 2um;

[0076] S4, after sputtering, Zr target shutter is closed and Si target shutter is kept open, FeCrAl target shutter is closed, Ar gas is introduced and glow sputtering is started;Sputtering pressure is 0.6Pa, pulse bias is-200V, single target power is controlled independently, wherein the sputtering power of FeCrAl alloy target is 300W, and the sputtering power of Y target is 50W, sputtering time is 3h, and the obtained FeCrAlZr coating thickness is about 3um;

[0077] S5, after sputtering, open the Zr target shutter, close the Si target shutter and keep the FeCrAl target shutter closed, introduce Ar gas and glow sputter; the sputtering pressure is 0.6 Pa, the pulse bias is -200 V, the single target material power is controlled independently, wherein the sputtering power of the FeCrAl alloy target material is 300 W, the sputtering power of the Si target material is 60 W, the sputtering time is 2 h, and the obtained FeCrAlSi coating thickness is about 2 um;

[0078] S6, after sputtering, close the Zr target shutter, and keep the Si target and FeCrAl target shutters closed, introduce Ar gas and glow sputter; the sputtering pressure is 0.8 Pa, the pulse bias is -200 V, the single target material power is controlled independently, wherein the sputtering power of the FeCrAl alloy target material is 300 W, the sputtering power of the Si target material is 60 W, the sputtering power of the Y target material is 50 W, the sputtering time is 4 h, and the obtained FeCrAlSiZr coating thickness is about 4 um;

[0079] S7, after sputtering, open the Zr target, Si target and FeCrAl target shutters respectively; naturally cool the cavity to room temperature and close the molecular pump and mechanical pump, and take out the sample for standby.

[0080] Example 5

[0081] The embodiment provides a kind of corrosion-resistant multilayer composite coating, including sequentially arranged in the surface of substrate 1 bottom coating 2, intermediate coating one 3, intermediate coating two 4 and surface coating 5, the bottom coating 2 is FeCrAl coating, intermediate coating one 3 is FeCrAlTi coating, intermediate coating two 4 is FeCrAlSi coating, and surface coating 5 is FeCrAlSiTi coating.

[0082] A kind of corrosion-resistant multilayer composite coating preparation method, comprising the following steps:

[0083] S1, ferrite / martensite stainless steel (T91) is cut into round piece with diameter of 10 mm and thickness of 1.5 mm by electric spark wire cutting equipment;

[0084] S2, the round piece obtained in step S1 is polished with 400, 600, 800, 1000, 2000, 3000 and 5000 purpose water-based SiC sandpaper respectively, and is polished to mirror surface with W3.5-W0.01 diamond polishing paste, then the polished round piece is ultrasonically cleaned with acetone and alcohol for 20 minutes and dried for standby;

[0085] S3, the cleaned sample obtained in step S2 is fixed on the magnetron sputtering sample table for 16 times, and FeCrAl alloy target (the content of Cr is 15wt%, and the content of Al is 10wt%), Ti target and Si target are installed; then the mechanical pump, the molecular pump, the Ti target shutter, the Si target shutter, the heating, the FeCrAl target shutter are opened respectively, the heating temperature is set to 300 DEG C to improve the coating and the substrate bonding force, and the cavity vacuum degree reaches 6.0*10 -4 After Pa, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.6Pa, the pulse bias is-200V, the sputtering power is 300W, the sputtering time is 2h, and the obtained FeCrAl coating thickness is about 2um;

[0086] S4, after sputtering, the Ti target shutter is closed and the Si target shutter is kept open, the FeCrAl target shutter is closed, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.6Pa, the pulse bias is-200V, the single target power is controlled independently, wherein the sputtering power of the FeCrAl alloy target is 300W, the sputtering power of the Y target is 50W, the sputtering time is 3h, and the obtained FeCrAlTi coating thickness is about 3um;

[0087] S5, after sputtering, the Ti target shutter is opened, the Si target shutter is closed and the FeCrAl target shutter is kept closed, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.6Pa, the pulse bias is-200V, the single target power is controlled independently, wherein the sputtering power of the FeCrAl alloy target is 300W, the sputtering power of the Si target is 60W, the sputtering time is 2h, and the obtained FeCrAlSi coating thickness is about 2um;

[0088] S6, after sputtering, the Ti target shutter is closed, and the Si target and the FeCrAl target shutter are kept closed, Ar gas is introduced and glow sputtering is started; the sputtering pressure is 0.8Pa, the pulse bias is-200V, the single target power is controlled independently, wherein the sputtering power of the FeCrAl alloy target is 300W, the sputtering power of the Si target is 60W, the sputtering power of the Y target is 50W, the sputtering time is 4h, and the obtained FeCrAlSiTi coating thickness is about 4um;

[0089] S7, after sputtering, the Ti target, the Si target and the FeCrAl target shutter are opened respectively; the cavity is naturally cooled to room temperature and the molecular pump and the mechanical pump are closed, and the sample is taken out for standby.

[0090] Example 6

[0091] The embodiment provides a kind of corrosion-resistant multilayer composite coating, including sequentially arranged in the surface of base 1 bottom coating 2, intermediate coating one 3, intermediate coating two 4 and surface coating 5, the bottom coating 2 is FeCrAl coating, intermediate coating one 3 is FeCrAlTi coating, intermediate coating two 4 is FeCrAlZr coating, and surface coating 5 is FeCrAlTiZr coating.

[0092] A kind of corrosion-resistant multilayer composite coating preparation method, comprising the following steps:

[0093] S1, ferrite / martensite stainless steel (T91) is cut into round piece with diameter of 10mm and thickness of 1.5mm by spark erosion wire cutting equipment;

[0094] S2, the round piece obtained in step S1 is respectively polished with 400, 600, 800, 1000, 2000, 3000, 5000 purpose water-based SiC sandpaper, and is respectively polished to mirror surface with W3.5-W0.01 diamond polishing paste, then the polished round piece is ultrasonically cleaned with acetone, alcohol for 20 minutes and dried for standby use;

[0095] S3, the sample cleaned in step S2 is fixed on magnetron sputtering sample table for 16 times, and FeCrAl alloy target (the content of Cr is 15wt%, and the content of Al is 10wt%), Ti target and Zr target are installed;Then respectively open mechanical pump, molecular pump, Ti target shutter, Zr target shutter, heating, close FeCrAl target block, and heating temperature is set to 300 DEG C to improve the adhesion of coating and substrate, after the cavity vacuum degree reaches 6.0x10 -4 Pa, Ar gas is introduced and glow sputtering is started;Sputtering pressure is 0.6Pa, pulse bias is-200V, sputtering power is 300W, sputtering time is 2h, and the obtained FeCrAl coating thickness is about 2um;

[0096] S4, after sputtering, Ti target shutter is closed and Zr target shutter is kept open, FeCrAl target shutter is closed, Ar gas is introduced and glow sputtering is started;Sputtering pressure is 0.6Pa, pulse bias is-200V, and single target power is controlled independently, wherein the sputtering power of FeCrAl alloy target is 300W, and the sputtering power of Y target is 50W, sputtering time is 3h, and the obtained FeCrAlTi coating thickness is about 3um;

[0097] S5, after sputtering, open the Ti target shutter, close the Zr target shutter and keep the FeCrAl target shutter closed, introduce Ar gas and glow sputtering; the sputtering pressure is 0.6 Pa, the pulse bias is -200 V, the single target material power is controlled independently, wherein the sputtering power of the FeCrAl alloy target material is 300 W, the sputtering power of the Si target material is 60 W, the sputtering time is 2 h, and the obtained FeCrAlZr coating thickness is about 2 um;

[0098] S6, after sputtering, close the Ti target shutter, and keep the Zr target and FeCrAl target shutters closed, introduce Ar gas and glow sputtering; the sputtering pressure is 0.8 Pa, the pulse bias is -200 V, the single target material power is controlled independently, wherein the sputtering power of the FeCrAl alloy target material is 300 W, the sputtering power of the Si target material is 60 W, the sputtering power of the Y target material is 50 W, the sputtering time is 4 h, and the obtained FeCrAlTiZr coating thickness is about 4 um;

[0099] S7, after sputtering, open the Ti target, Zr target and FeCrAl target shutters respectively; naturally cool the cavity to room temperature and close the molecular pump and mechanical pump, and take out the sample for standby.

[0100] Comparative example

[0101] The difference between the present comparative example and example 1 is that the FeCrAlYSi coating is first sputtered on the surface of the substrate, and then the single element target material is replaced by an Al2O3 ceramic target material, the preparation method and setting parameters are the same as those of example 1, and finally the obtained corrosion-resistant multilayer composite coating is a FeCrAlYSi-Al2O3 coating.

[0102] In order to test the performance of the corrosion-resistant multilayer composite coating prepared by the present application, the samples prepared in example 1 and the comparative example are taken as experimental objects, and the coating and substrate adhesion is tested by an automatic scratch tester, as shown in Figure 2 The coating and substrate adhesion strength test diagram of the corrosion-resistant multilayer composite coating (metal multilayer coating) of the present example 1, Figure 3 The coating and substrate adhesion strength test diagram of the corrosion-resistant multilayer composite coating (metal + ceramic multilayer coating) of the comparative example. From Figure 2 and Figure 3 It can be seen from the comparison of the above that the coating prepared by the present application is well combined with the substrate, and the coating does not appear any peeling phenomenon, while the comparative example appears a lot of peeling around the scratch, and the adhesion strength with the substrate is low.

[0103] The coating prepared in example 1 of the present application has good thermal shock resistance at ΔT = 1200℃, and the coating does not appear peeling.

[0104] The coating prepared by the embodiment 1 of the present application still maintains the metal luster on the coating surface after 1000h corrosion at 600℃ in static lead / lead bismuth environment under the condition of corrosion and oxygen-poor; as shown in Figure 4 As can be observed under the scanning electron microscope, the coating surface after corrosion contains a large number of circles, as shown in Figure 4 As shown in the figure, the coating surface morphology of the corrosion-resistant multilayer coating of embodiment 1 after the corrosion test at 600℃, it can be observed under the scanning electron microscope that the coating surface after corrosion contains a large number of circles. The appearance of the circle-shaped morphology is usually derived from the poor wettability of LBE on the coating surface. Under the current conditions, a protective corrosion layer is generated on the coating surface. Therefore, the appearance of the circle-shaped morphology implies that there is an outward growing corrosion layer on the coating surface, and also implies the poor wettability of LBE on the surface of the protective corrosion layer. The non-wettability of the coating is crucial for the interaction between less LBE and the coating / substrate, which proves that the coating of the present application has good corrosion resistance in lead / lead bismuth environment.

[0105] In summary, the metal multilayer coating of the present application has good adhesion to the substrate, excellent thermal shock resistance, and excellent corrosion resistance in lead / lead bismuth alloy environment.

[0106] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A corrosion resistant multilayer composite coating characterized by, The coating comprises a bottom coating (2), an intermediate coating and a surface coating (5) arranged in sequence; The bottom coating (2) is an FeCrAl coating; The intermediate coating comprises an intermediate coating one (3) and an intermediate coating two (4), and the intermediate coating is any two of FeCrAlY coating, FeCrAlTi coating, FeCrAlZr coating and FeCrAlSi coating. The surface coating (5) is any one of FeCrAlYSi coating, FeCrAlYTi coating, FeCrAlYZr coating, FeCrAlSiZr coating, FeCrAlSiTi coating and FeCrAlTiZr coating.

2. The corrosion resistant multi-layer composite coating according to claim 1, wherein, The thickness of the corrosion-resistant multilayer composite coating is 1-30 microns.

3. A method for producing a corrosion-resistant multilayer composite coating, characterized by, The method comprises the following steps: S1: After polishing and polishing the substrate, ultrasonic cleaning and drying are performed for standby; S2: The cleaned substrate is fixed on a magnetron sputtering sample table, an FeCrAl alloy target and a single element target are installed, and the single element target is any two of Si, Zr, Y and Ti; S3: Single target, double target and triple target co-sputtering are used to obtain a bottom coating FeCrAl coating, an intermediate coating and a surface coating on the substrate surface in sequence, the intermediate coating comprises an intermediate coating one and an intermediate coating two, and the intermediate coating is any two of FeCrAlY coating, FeCrAlTi coating, FeCrAlZr coating and FeCrAlSi coating.

4. A method of producing a corrosion resistant multi-layer composite coating according to claim 3, characterized in that, S1 is specifically: After polishing the substrate with sandpaper, polish it to a mirror surface with diamond polishing paste, then ultrasonic clean it with acetone and alcohol for 20 minutes, and dry it for standby.

5. A method of producing a corrosion resistant multi-layer composite coating according to claim 4, characterized in that, The sandpaper is water-based SiC sandpaper with a roughness of 400-5000 mesh, and the diamond polishing paste is water-soluble diamond polishing paste.

6. The method of claim 3, wherein the corrosion resistant multilayer composite coating is prepared by a process comprising: The preparation method of the bottom coating is: Open the mechanical pump, molecular pump, single element target shutter, close the FeCrAl alloy target shutter, heat, and wait until the vacuum degree of the cavity reaches 10 -3 ~10 -4 After 10 Pa, Ar gas is introduced and glow sputtering is started, and a bottom coating FeCrAl coating is obtained under the conditions of a sputtering pressure of 0.5-1.0 Pa, a pulse bias voltage of-50-200 V, a sputtering power of 100-500 W, and a sputtering time of 1-5 h.

7. The method of claim 3, wherein the corrosion resistant multilayer composite coating is prepared by a process comprising: The preparation method of the intermediate coating is: After single target sputtering, the shutter of any one of the single element targets is closed, the shutter of the FeCrAl target is kept closed, the shutters of the remaining targets are opened, Ar gas is introduced and glow sputtering is started, the sputtering pressure is 0.5-1.0 Pa, the pulse bias is-50-200 V, the sputtering power of the FeCrAl alloy target is 100-500 W, the sputtering power of the single element target is 30-100 W, the sputtering time is 1-5 h, and the intermediate coating one is obtained. Repeat the above steps to obtain the intermediate coating two.

8. The method of claim 3, wherein the corrosion resistant multilayer composite coating is prepared by, The preparation method of the surface coating is: After double target sputtering, the shutters of the two single element targets are closed, the shutter of the FeCrAl target is kept closed, Ar gas is introduced and glow sputtering is started, the sputtering pressure is 0.5-1.0 Pa, the pulse bias is-50-200 V, the sputtering power of the FeCrAl alloy target is 100-500 W, the sputtering power of the single element target is 30-100 W, the sputtering time is 1-5 h, and the surface coating is obtained.

9. The method of claim 3, wherein the corrosion resistant multilayer composite coating is prepared by, The substrate is austenitic stainless steel or ferritic / martensitic stainless steel.

10. The method of claim 3, wherein the corrosion resistant multilayer composite coating is prepared by, In the FeCrAl alloy target, the content of Cr is 9-20wt%, the content of Al is 4-15wt%, and the rest is Fe.

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