Corrosion-resistant iron-based amorphous material suitable for ultrahigh-speed laser cladding and preparation method of corrosion-resistant iron-based amorphous material

Abstract

The invention provides a corrosion-resistant iron-based amorphous material suitable for ultrahigh-speed laser cladding and a preparation method of the corrosion-resistant iron-based amorphous material. The corrosion-resistant iron-based amorphous material is characterized in that an iron-based amorphous coating comprises the following components in percentage by weight: 27-29 wt% of Cr, 2-3 wt% of Co, 1-3 wt% of Nb, 3-5 wt% of Mo, 5-8 wt% of Ce, 3.6-3.8 wt% of B, 4.3-4.5 wt% of Si, 0.7-0.9 wt% of C and the balance of Fe. Amorphous alloy powder is prepared by combining vacuum induction melting with a gas atomization powder preparation technology, a coating is prepared on the surface of a base body by adopting an ultra-high-speed laser cladding technology, the coating has high amorphous content and excellent corrosion resistance, and meanwhile, low porosity (llt) is achieved through the ultra-high-speed laser cladding technology; the coating has the advantages of high hardness (greater than or equal to 800HV) and strong bonding strength (greater than or equal to 70MPa), prolongs the service life of maritime work equipment in a marine environment, is suitable for industrial popularization, is suitable for surface protection of marine equipment, chemical equipment and other severe environments, and has the advantages of efficient process, environmental protection, low cost and strong corrosion resistance.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of material processing, and in particular to a corrosion-resistant iron-based amorphous material suitable for super-high-speed laser cladding and a preparation method thereof. BACKGROUND

[0002] Iron-based amorphous alloys exhibit excellent corrosion resistance due to their unique amorphous structure (long-range disorder, short-range order) and have important application value in the field of surface protection of marine engineering equipment. Marine environment has characteristics such as high salinity, high humidity and strong corrosion, and traditional metal materials (such as carbon steel, stainless steel, etc.) are prone to uniform corrosion, pitting and stress corrosion cracking when exposed to seawater environment for a long time, which seriously affects the service life and safety of the equipment.

[0003] At present, the corrosion protection in marine environment mainly adopts methods such as organic coating, metal coating and alloying modification. Although the organic coating (such as epoxy resin, polyurethane, etc.) has certain corrosion resistance, it is prone to swelling and peeling after long-term immersion, and the mechanical properties are poor; the metal coating (such as nickel-based alloy, zinc-aluminum alloy, etc.) has good corrosion resistance, but the crystal defects such as grain boundary and dislocation may still become the starting point of corrosion, leading to accelerated local corrosion. In comparison, the iron-based amorphous alloy can effectively inhibit electrochemical corrosion due to its uniform structure without grain boundaries and dislocations, and its high chemical stability can promote the formation of a dense passivation film, significantly improving the seawater corrosion resistance.

[0004] However, the iron-based amorphous coating obtained by traditional preparation methods (such as thermal spraying, cladding, etc.) often has problems such as high porosity and insufficient amorphous phase content, which affects its long-term corrosion resistance. The super-high-speed laser cladding technology (EHLA) can significantly improve the amorphous forming ability due to its extremely high cooling rate (10 6 ~10 8 K / s), and can ensure that the coating is dense and has strong adhesion, which is an ideal process for preparing high-performance iron-based amorphous coatings. Therefore, developing a corrosion-resistant iron-based amorphous coating suitable for super-high-speed laser cladding is of great significance for improving the long-term stability of marine equipment in harsh corrosion environments. SUMMARY

[0005] The main technical problem to be solved by the application is that the iron-based amorphous coating obtained by traditional preparation methods (such as thermal spraying, cladding, etc.) often has problems such as high porosity and insufficient amorphous phase content, which affects its long-term corrosion resistance, in order to overcome the above-mentioned defects in the prior art, a The technical scheme adopted by the application to solve the technical problem is: An anticorrosion iron-based amorphous material suitable for super-high-speed laser cladding, characterized in that the iron-based amorphous coating comprises the following components in percentage by weight: 27-29wt% Cr, 2-3wt% Co, 1-3wt% Nb, 3-5wt% Mo, 5-8wt% Ce, 3.6-3.8wt% B, 4.3-4.5wt% Si, 0.7-0.9wt% C, and the balance of Fe.

[0006] Further, the iron-based amorphous coating comprises the following components in percentage by weight: 28wt% Cr, 2.5wt% Co, 2wt% Nb, 4wt% Mo, 6.5wt% Ce, 3.7wt% B, 4.4wt% Si, 0.8wt% C, and the balance of Fe.

[0007] A preparation method of an anticorrosion iron-based amorphous material suitable for super-high-speed laser cladding, characterized in that it comprises the following steps: S1. According to the above iron-based amorphous composition and weight ratio, high-carbon chromium iron, low-carbon chromium iron, cobalt iron, niobium iron, molybdenum iron, cerium powder, boron carbide and silicon iron are weighed, and are added into a vacuum induction electromagnetic furnace according to the principle of high melting point first and low melting point later, and then are heated to fully melt; S2. The molten mixed liquid is subjected to vacuum gas atomization treatment, the gas atomization gas is argon, the vacuum degree of the atomization chamber is 5-10Pa, the argon pressure is 3MPa, and the dry, sieved powder with a particle size of 53-150μm after gas atomization is obtained to obtain the iron-based amorphous powder.

[0008] Further, the induction electromagnetic furnace in step S1 has a heating rate of 50-60K / s.

[0009] Further, the drying temperature in step S2 is 80-120℃, and the drying time is 2-4h.

[0010] An application of an anticorrosion iron-based amorphous material suitable for super-high-speed laser cladding in preparing a corrosion-resistant coating, comprising the following steps: S1. After the surface of the substrate is degreased and derusted, brown corundum sand with a particle size of 5-35 mesh is used to perform sandblasting and roughening treatment on the substrate under a gas pressure of 0.7-0.8MPa; S2. The powder is sprayed by using a super-high-speed laser cladding device, and the process parameters are as follows: laser power 2000-2500W, scanning speed 800-1200mm / s, light spot diameter 1.5-2.0mm, powder feeding rate 10-15g / min, protective gas flow rate 15-20L / min, and overlap rate 30-40%.

[0011] Further, the protective gas in step S2 is argon.

[0012] The beneficial effects of the present application are: 1、The iron-based amorphous coating prepared by the super-high-speed laser cladding technology has low porosity, high hardness and bonding strength, excellent corrosion resistance, is suitable for harsh corrosive environments such as marine engineering equipment and chemical equipment, is easy to industrialize, and has wide market application prospect.

[0013] 2、In the iron-based amorphous material, industrial-grade alloy raw materials are used for smelting, and compared with the traditional high-purity metal raw material scheme, the raw material cost of the prepared amorphous material is significantly reduced.

[0014] 3、The design of the iron-based amorphous composition makes it have good amorphous forming ability, through optimization of the proportioning of Cr, Mo, Ce and other elements, combined with the rapid cooling characteristics (10 6 ~10 8 K / s) of the super-high-speed laser cladding, a coating with amorphous phase content ≥95% can be prepared.

[0015] 4、Through the combined action of high content of Cr and Ce, the formation of dense passivation film is promoted, and the corrosion resistance of the coating is significantly improved, and experiments show that the corrosion rate in 3.5% NaCl solution is ≤0.01mm / year; 5、The super-high-speed laser cladding technology is used to prepare a dense coating with porosity ≤1% on the surface of the base material, and the microhardness of the coating is ≥800HV 0.3 .

[0016] 6. The amorphous alloy powder is prepared by vacuum induction melting combined with gas atomization powder preparation technology, and the coating is prepared on the surface of the substrate by the super-high-speed laser cladding technology. The coating has high amorphous content and excellent corrosion resistance. At the same time, through the super-high-speed laser cladding process, low porosity (<1%), high hardness (≥800HV) and strong bonding strength (≥70MPa) are realized, the service life of marine equipment in marine environment is improved, and industrialization is suitable. The present application is suitable for surface protection of marine equipment, chemical equipment and other harsh environments, and has the advantages of efficient process, environmental protection, low cost and strong corrosion resistance. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present application will be further described below in combination with the drawings and examples.

[0018] Figure 1 The XRD characterization spectrum of Example 1 and Comparative Example 2. DETAILED DESCRIPTION

[0019] The present application will be further described below in combination with the drawings and examples.

[0020] Example: As Figure 1The application discloses an anti-corrosion iron-based amorphous coating suitable for super-high-speed laser cladding and a preparation method thereof.

[0021] In embodiment 1, the anti-corrosion iron-based amorphous material suitable for super-high-speed laser cladding comprises the following components in percentage by weight: 28wt% of Cr, 2.5wt% of Co, 2wt% of Nb, 4wt% of Mo, 6.5wt% of Ce, 3.7wt% of B, 4.4wt% of Si, 0.8wt% of C, and the balance of Fe.

[0022] The anti-corrosion iron-based amorphous material suitable for super-high-speed laser cladding is prepared by the following steps. In the first step, high-carbon chromium iron, low-carbon chromium iron, cobalt iron, niobium iron, molybdenum iron, cerium powder, boron carbide and silicon iron are weighed according to the above-mentioned iron-based amorphous component and weight ratio, and are added into a vacuum induction electromagnetic furnace according to the principle of high melting point first and low melting point later, and then are heated to be completely melted. In the second step, the molten mixed liquid is subjected to vacuum gas atomization treatment, argon is used as the gas atomization gas, the vacuum degree of the atomization chamber is 5-10 Pa, the argon pressure is 3 MPa, and the powder with a particle size of 53-150 μm after drying and screening is obtained to obtain the iron-based amorphous powder.

[0023] The anti-corrosion iron-based amorphous material is applied in the preparation of the anti-corrosion coating, and the specific application steps are as follows. In the first step, after the surface of the substrate is degreased and derusted, brown corundum sand with a particle size of 5-35 mesh is used to perform sand blasting and roughening treatment on the surface of the substrate under the condition that the air pressure is 0.7-0.8 MPa. In the second step, the powder is sprayed by using the super-high-speed laser cladding equipment, and the process parameters are as follows: the laser power is 2000-2500 W, the scanning speed is 800-1200 mm / s, the light spot diameter is 1.5-2.0 mm, the powder feeding rate is 10-15 g / min, the protective gas (argon) flow rate is 15-20 L / min, and the overlap rate is 30-40%.

[0024] In embodiment 2, the anti-corrosion iron-based amorphous material suitable for super-high-speed laser cladding comprises the following components in percentage by weight: 27wt% of Cr, 2wt% of Co, 1wt% of Nb, 3wt% of Mo, 5wt% of Ce, 3.6wt% of B, 4.3wt% of Si, 0.7wt% of C, and the balance of Fe.

[0025] The preparation method of the anti-corrosion iron-based amorphous material suitable for super-high-speed laser cladding, the application of the iron-based amorphous material in the coating and the construction method in this embodiment are the same as those in embodiment 1.

[0026] Example 3, a corrosion resistant Fe-based amorphous material suitable for ultra-high speed laser cladding, the Fe-based amorphous coating comprising the following components in weight percentage: 29wt% Cr, 3wt% Co, 3wt% Nb, 5wt% Mo, 8wt% Ce, 3.8wt% B, 4.5wt% Si, 0.9wt% C, balance Fe The preparation method of the corrosion resistant Fe-based amorphous material suitable for ultra-high speed laser cladding, the application of the Fe-based amorphous material in the coating and the construction method in this example are the same as those in Example 1.

[0027] Example 4, a coating is prepared by using commercial FeCrMoBCSi Fe-based amorphous, the Fe-based amorphous coating comprising the following components in weight percentage: 26wt% Cr, 17wt% Mo, 8wt% Ce, 2.5wt% B, 2.5wt% C, 0.5wt% Si, balance Fe.

[0028] The application of the FeCrMoBC Fe-based amorphous in the coating and the construction method in this example are the same as those in Example 1.

[0029] Comparative Example 1, a Fe-based amorphous / nanocrystalline composite coating is prepared as a comparative material, the Fe-based amorphous / nanocrystalline composite material comprising the following components in weight percentage: 28wt% Cr, 2.5wt% Co, 2wt% Nb, 4wt% Mo, 6.5wt% Ce, 3.7wt% B, 3wt% Si, 0.8wt% C, balance Fe.

[0030] The preparation method of the corrosion resistant Fe-based amorphous material suitable for ultra-high speed laser cladding, the application of the Fe-based amorphous material in the coating and the construction method in this example are the same as those in Example 1.

[0031] Comparative Example 2, a corrosion resistant Fe-based amorphous material suitable for ultra-high speed laser cladding, the Fe-based amorphous coating comprising the following components in weight percentage: 28wt% Cr, 2.5wt% Co, 2wt% Nb, 4wt% Mo, 3.7wt% B, 4.4wt% Si, 0.8wt% C, balance Fe.

[0032] The preparation method of the corrosion resistant Fe-based amorphous material suitable for ultra-high speed laser cladding, the application of the Fe-based amorphous material in the coating and the construction method in this example are the same as those in Example 1.

[0033] Comparative Example 3, a corrosion resistant Fe-based amorphous material suitable for ultra-high speed laser cladding, the Fe-based amorphous coating comprising the following components in weight percentage: 28wt% Cr, 2.5wt% Co, 2wt% Nb, 6.5wt% Ce, 3.7wt% B, 4.4wt% Si, 0.8wt% C, balance Fe.

[0034] The preparation method of the corrosion-resistant iron-based amorphous material suitable for super-high-speed laser cladding, the application of the iron-based amorphous material in the coating, and the construction method in the comparative example 1 are the same as those in the example 1.

[0035] The phase of the coating of the example 1 and the comparative examples 1-3 is characterized by XRD, Figure 1 For the XRD characterization spectrum of the example 1 and the comparative example 2, it can be seen from the figure that the relative intensity of the coating of the example 1 is much larger than that of the comparative example 2. The amorphous phase content in each coating is calculated by the Verdon method, and the amorphous phase content in the coating of the example 1 is 91%, and the amorphous phase content in the coatings of the comparative examples 1-3 is 50%, 36% and 43% respectively.

[0036] Through the comparison of the example 1 and the comparative examples 1-3, it can be known that the change of the elements in an amorphous system or the change of the element content will make the amorphous forming ability of the system worse. The system of the present application has excellent amorphous forming ability, and can be prepared into a coating with high amorphous content by using super-high-speed laser cladding technology. Among them, Cr is the main alloying element, which can form a dense passivation film, significantly improving the corrosion resistance of the coating; Co can optimize the atomic stacking density and improve the amorphous forming ability of the system; Nb as a large atomic element can increase the atomic mismatch degree, thereby improving the amorphous forming ability of the system; Mo can improve the pitting resistance and improve the service performance of the coating in marine environment; Ce has good deoxidizing and desulfurizing ability, which can remove impurity elements in the smelting process, and at the same time improve the self-repairing ability of the coating; B and Si as metalloid elements can reduce the critical cooling rate of amorphous alloy and improve the amorphous forming ability of the system. In addition, by adjusting the ratio of large atoms (Nb, Ce), medium atoms (Cr, Mo, Co) and small atoms (B, C, Si) in the amorphous system, the atomic mismatch between the atoms in the system can be increased to a certain extent, which will lead to the reduction of the free volume of the system and hinder the diffusion of elements, thereby improving the amorphous forming ability and stability of the system.

[0037] The porosity, microhardness and corrosion resistance of the coating prepared from the corrosion-resistant iron-based amorphous material suitable for super-high-speed laser cladding in the above examples 1-3 and the existing FeCrMoBCSi coating of the example 4 are tested. In the present embodiment, the porosity of the coating is measured by the gray scale method according to the DT2000 image analysis software; the microhardness of the coating is measured by the HXD-1000TC microhardness tester, the test load is 300g, and the load holding time is 15s; the seawater corrosion resistance of the coating is measured by the CREST CS350H electrochemical workstation. The test results are as follows: Test results table Compared with the existing iron-based amorphous material, the iron-based amorphous material of the application forms a dense passivation film by adding Ce in combination with high Cr content, thereby improving the corrosion resistance of the system, so that the coating of the application has a lower corrosion rate, that is, the iron-based amorphous material of the application exhibits excellent corrosion resistance, and has outstanding substantial features and significant progress.

[0038] The iron-based amorphous coating prepared by the super-high-speed laser cladding technology has low porosity, high hardness and high bonding strength, has excellent corrosion resistance, is suitable for harsh corrosive environments such as marine engineering equipment and chemical equipment, is easy to be industrialized, has a wide market application prospect; in the iron-based amorphous material, industrial-grade alloy raw materials are used for smelting, compared with the traditional high-purity metal raw material scheme, the raw material cost of the prepared amorphous material is significantly reduced; the design of the composition of the iron-based amorphous material enables it to have good amorphous forming ability, by optimizing the ratio of Cr, Mo, Ce and other elements, in combination with the rapid cooling characteristics (10 6 ~10 8 K / s) of the super-high-speed laser cladding, an amorphous phase content≥95% coating can be prepared; by the combined action of high content of Cr and Ce, the formation of a dense passivation film is promoted, and the corrosion resistance of the coating is significantly improved, experiments show that the corrosion rate in 3.5% NaCl solution is≤0.01mm / year; by using the super-high-speed laser cladding technology, a dense coating with a porosity≤1% is prepared on the surface of the substrate material, and the microhardness of the coating is≥800HV 0.3 .

[0039] The amorphous alloy powder is prepared by vacuum induction melting combined with gas atomization powder preparation technology, and the coating is prepared on the surface of the substrate by using the super-high-speed laser cladding technology, the coating has high amorphous content and excellent corrosion resistance, at the same time, the low porosity (<1%), high hardness (≥800HV) and strong bonding strength (≥70MPa) are realized by the super-high-speed laser cladding process, the service life of the marine equipment in the marine environment is improved, and the application is suitable for industrialization. The application is suitable for surface protection in harsh environments such as marine equipment and chemical equipment, and has the advantages of efficient process, environmental protection, low cost and strong corrosion resistance.

[0040] The above is only a preferred embodiment of the application, and does not limit the application in any form, any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the application still belongs to the scope of the technical solution of the application.

Claims

1. A corrosion resistant iron-based amorphous material suitable for ultra-high speed laser cladding, characterized in that: The iron-based amorphous coating comprises the following ingredients by weight percentage: 27-29wt% Cr, 2-3wt% Co, 1-3wt% Nb, 3-5wt% Mo, 5-8wt% Ce, 3.6-3.8wt% B, 4.3-4.5wt% Si, 0.7-0.9wt% C, and the balance of Fe.

2. The corrosion resistant Fe-based amorphous material suitable for ultrafast laser cladding according to claim 1, characterized in that: The iron-based amorphous coating comprises the following ingredients by weight percentage: 28wt% Cr, 2.5wt% Co, 2wt% Nb, 4wt% Mo, 6.5wt% Ce, 3.7wt% B, 4.4wt% Si, 0.8wt% C, and the balance of Fe.

3. The method according to claim 1 or 2, characterized in that, The method comprises the following steps: S1. According to the above iron-based amorphous composition and weight ratio, high-carbon chromium iron, low-carbon chromium iron, cobalt iron, niobium iron, molybdenum iron, cerium powder, boron carbide and silicon iron are weighed and added to a vacuum induction electromagnetic furnace in the order of high melting point first and low melting point last, and then heated to melt them all; S2. The molten mixed liquid is subjected to vacuum gas atomization treatment, the gas atomization gas is argon, the vacuum degree of the atomization chamber is 5-10 Pa, the argon pressure is 3 MPa, and the dry, sieved powder with a particle size of 53-150 μm after gas atomization is obtained. Iron-based amorphous powder.

4. The method according to claim 3, characterized in that: The induction electromagnetic furnace in step S1 has a heating rate of 50-60 K / s.

5. The method according to claim 3, wherein the method is characterized in that: The drying temperature in step S2 is 80-120℃, and the drying time is 2-4h.

6. The use of the corrosion-resistant iron-based amorphous material according to claim 1 or 2 for preparing a corrosion-resistant coating layer, characterized in that, The method comprises the following steps: S1. After the surface of the substrate is degreased and derusted, it is subjected to sandblasting and roughening treatment under a gas pressure of 0.7-0.8 MPa using brown corundum sand with a particle size of 5-35 mesh; S2. The powder is sprayed using a super-high-speed laser cladding device, and the process parameters are: laser power 2000-2500 W, scanning speed 800-1200 mm / s, spot diameter 1.5-2.0 mm, powder feeding rate 10-15 g / min, protective gas flow 15-20 L / min, and overlap rate 30-40%.

7. Use according to claim 6, characterized in that, The protective gas in step S2 is argon.

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