Wear-resistant and corrosion-resistant iron-based amorphous coating slurry and preparation method of coating

Abstract

The invention discloses a wear-resistant and corrosion-resistant iron-based amorphous coating slurry and a preparation method of a coating, and belongs to the technical field of equipment coatings, the wear-resistant and corrosion-resistant iron-based amorphous coating slurry comprises 52-65% of iron-based amorphous composite powder and the balance of a binder; the iron-based amorphous composite powder is obtained by mixing completely amorphous iron-based amorphous powder and Mo powder according to the mass ratio of (94-98): (2-6). The preparation period of the coating on the surface of the ball core is effectively shortened, the prepared coating is excellent in performance, meanwhile, waste of coating materials is reduced, the service life of the ball valve ball core is prolonged, and meanwhile the production cost is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of equipment coatings, and in particular to a wear-resistant and corrosion-resistant iron-based amorphous coating slurry on the surface of a stainless steel ball valve core and a method for preparing the coating. Background Art

[0002] In the fields of aerospace, nuclear energy, marine engineering and military equipment, coating technology has become the core technology for improving the reliability of key equipment, extending its service life and ensuring safety. It is also the basis for enhancing my country's strategic scientific and technological strength and independent innovation capabilities. Breakthroughs in marine engineering and nuclear energy technology have far-reaching significance for my country's energy independence and green and low-carbon development. Technological innovation in the fields of aerospace and military equipment is related to the country's scientific and technological competitiveness and national defense security. At present, the service life of the ball core of a ball valve used under extreme working conditions is relatively short, and it usually needs to have excellent corrosion resistance and wear resistance to reliably fulfill its important role under extreme working conditions.

[0003] In the market, the preparation process for the surface coating of the ball core usually adopts thermal spraying technology to spray nickel-based alloy powder, and then forms the coating through turning. The coating prepared by this method can meet the service requirements of the ball core under normal working conditions, but the production cycle of a single ball core coating is long, and the bonding strength of the coating prepared by this process is low. The coating has a certain porosity, and the service life is greatly shortened when used under extreme working conditions. At the same time, the coating prepared by the common production process has the problem of high waste of coating materials and non-recyclability.

[0004] Therefore, providing a high-efficiency, low-cost production performance of a ball core with excellent wear-resistant and corrosion-resistant iron-based amorphous coating is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of this, the present invention provides a preparation method of a wear-resistant and corrosion-resistant iron-based amorphous coating slurry and a coating on the surface of a stainless steel ball valve core.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A wear-resistant and corrosion-resistant iron-based amorphous coating slurry, composed of the following raw materials by mass fraction: 52-65% of iron-based amorphous composite powder and the rest being a binder;

[0008] The iron-based amorphous composite powder is obtained by mixing completely amorphous iron-based amorphous powder and Mo powder in a mass ratio of 94-98:2-6.

[0009] Furthermore, the particle size of the iron-based amorphous composite powder is 15-53 μm;

[0010] Furthermore, the completely amorphous iron-based amorphous powder is composed of the following elements in mass fraction: Cr 2.2%-2.8%, B 2.2%-2.8%, C 0.5%-1%, Si 6.4%-7%, and the rest is Fe.

[0011] The beneficial effect of adopting the above further scheme is that: in the above element composition of the present invention, the B element can inhibit the growth of grains, making it more difficult for the coating structure to transform from an amorphous phase to a crystalline phase, thereby improving the strength, toughness and plasticity of the alloy; the Cr element has a strong passivation ability in many corrosion-resistant environments. After adding 2-6% of pure Mo powder to the iron-based amorphous powder, the Cr and Mo elements form a synergistic effect, which can further improve the passivation ability and corrosion resistance of the alloy in a corrosion-resistant environment. The chromium oxide passivation film formed by the Cr element provides basic protection, and the addition of the Mo element can improve the structure and performance of the passivation film, making it more dense and stable, improving the resistance to corrosive media such as chloride ions, and enhancing the passivation effect and corrosion resistance of the alloy in various complex corrosion-resistant environments. The composite powder has no precious metal elements, the overall price is low, and the production cost is effectively reduced.

[0012] Furthermore, the binder is composed of the following raw materials in mass fraction: 1%-5% phenolic resin, 1%-5% aluminum dihydrogen phosphate, 5%-10% sodium silicate, and the rest is alcohol.

[0013] The beneficial effect of adopting the above further scheme is that the phenolic resin in the above binder serves as the base of the binder, providing basic bonding force and film-forming properties, so that the alloy powder can be firmly attached to the surface of the base, while giving the binder sufficient mechanical strength and chemical stability. The heat resistance of aluminum dihydrogen phosphate is excellent and can be used in a high temperature environment above 1000°C, so that the binder has high bonding strength and hardness, the coating has good wear resistance, its curing speed is fast, and the production efficiency is high. Sodium silicate has good chemical stability, strong corrosion resistance, and can resist the erosion of acid and alkali media. Alcohol plays a diluting role, which promotes the fluidity and expansibility of the slurry.

[0014] The present invention also provides a method for preparing a wear-resistant and corrosion-resistant iron-based amorphous coating, comprising the following steps:

[0015] (1) Prepare the sample: sandblast the sample, then use an ultrasonic cleaning device to clean the sample surface and dry the sample;

[0016] (2) preparing slurry: preparing slurry according to the above mass fraction, placing the prepared slurry in a ball mill for ball milling, and then taking it out for use;

[0017] (3) Slurry: immerse the sample in the slurry, rotate the sample for 5-8 seconds and take it out;

[0018] (4) Drying: Place the coated sample in a drying oven at 200-300°C for 30-45 min, then leave it in the air for 20-24 h to allow the coating to fully dry.

[0019] (5) Cladding: The dried sample is fixed by a chuck, placed flat on a rotating carrier, and laser cladding is performed using a cladding device;

[0020] (6) Sampling: After laser cladding, remove the sample and place it in a drying oven. Cool it down by 50°C every 15-20 minutes from 300°C. Keep it at room temperature for 10 minutes each time until it reaches room temperature before taking it out.

[0021] Furthermore, in step (2), the ball milling speed is 200-250 r / min, and the ball milling time is 1 h.

[0022] Furthermore, the slurry coating in step (3) is repeated multiple times until the slurry coating thickness on the surface of the sample is 1-1.5 mm.

[0023] The beneficial effects of the present invention are as follows: in view of the fact that the existing ball core coating preparation process is mostly thermal spraying technology, the prepared coating has poor bonding strength with the substrate and has a certain porosity, the service life of the ball valve ball core produced under extreme working conditions is short, and the coating preparation cycle is long, and the preparation process has the phenomenon of waste of coating materials that cannot be recycled. The present invention effectively shortens the preparation cycle of the ball core surface coating, the prepared coating has excellent performance and reduces the waste of coating materials, increases the service life of the ball valve ball core and effectively reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The surface morphology of the sample of Example 1 of the present invention after immersion and drying and the surface morphology after sintering;

[0025] Figure 2 The surface morphology of the sample of Example 2 of the present invention after immersion and drying and the surface morphology after sintering;

[0026] Figure 3 These are the surface morphology images of the sample of Example 3 of the present invention after immersion drying and after sintering.

[0027] Figure 4 This is a hardness test diagram of the sample of Example 1 of the present invention;

[0028] Figure 5 This is a hardness test diagram of the sample of Example 2 of the present invention;

[0029] Figure 6 This is a hardness test diagram of the sample of Example 3 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] (1) Prepare the sample: sandblast the sample, then use an ultrasonic cleaning device to clean the sample surface and dry the sample;

[0033] (2) preparing an iron-based amorphous composite powder and a binder: preparing an iron-based amorphous composite powder according to weight percentage, taking 96% of completely amorphous powder and 4% of pure Mo powder and grinding them in a ball mill for 2 h at a speed of 200 r / min, and then taking them out for use;

[0034] Prepare a binder with a composition of 1% phenolic resin, 5% sodium silicate, 1% aluminum dihydrogen phosphate, and the remainder alcohol;

[0035] (3) preparing slurry: the slurry composition is: 55% of iron-based amorphous composite powder and 45% of binder. The prepared slurry is placed in a ball mill and ground for 1 hour at a speed of 200 r / min, and then taken out for use;

[0036] (4) Slurry coating: immerse the sample (ball core) in the slurry, rotate the sample clockwise for 5 seconds and take it out. The slurry coating thickness is 1.2 mm;

[0037] (5) Drying: Place the coated sample in a drying oven at 200°C for 45 min, and then leave it in air for 24 h to allow the coating to dry fully and prevent defects such as bubbles that affect the coating quality during the laser cladding process;

[0038] (6) Cladding: Fix the dried sample with a chuck and place it flat on the rotating carrier. Adjust the distance between the cladding equipment and the sample to maintain it at 10 mm. Set the running trajectory of the cladding equipment. Set the laser power of the cladding equipment to 950 W, the scanning speed to 600 mm / min, and the rotation speed of the sample to 100 mm / min. Start laser cladding.

[0039] (7) Sampling: The sample after laser cladding was removed and placed in a drying oven. The temperature was lowered by 50°C every 15 minutes from 300°C. After each temperature reduction, the sample was kept at room temperature for 10 minutes and then taken out to form a wear-resistant and corrosion-resistant iron-based amorphous coating. The Vickers hardness was measured to be 923.3 HV.

[0040] Example 2

[0041] (1) Prepare the sample: sandblast the sample, then use an ultrasonic cleaning device to clean the sample surface and dry the sample;

[0042] (2) preparing iron-based amorphous composite powder and binder: preparing iron-based amorphous composite powder according to weight percentage, taking 98% of completely amorphous powder and 2% of pure Mo powder and grinding them in a ball mill for 2 h at a speed of 225 r / min, and then taking them out for use;

[0043] Prepare a binder with a composition of 3% phenolic resin, 8% sodium silicate, 3% aluminum dihydrogen phosphate, and the remainder alcohol;

[0044] (3) Preparation of slurry: The slurry composition is: 60% iron-based amorphous composite powder, 40% binder. The prepared slurry is placed in a ball mill and ground for 1 hour at a speed of 250 r / min, and then taken out for use;

[0045] (4) Slurry coating: immerse the sample (ball core) into the slurry, rotate the sample clockwise for 7 seconds and take it out. The slurry coating thickness is 1 mm.

[0046] (5) Drying: Place the coated sample in a drying oven at 200°C for 45 min, and then leave it in air for 24 h to allow the coating to dry fully and prevent defects such as bubbles that affect the coating quality during the laser cladding process;

[0047] (6) Cladding: Fix the dried sample with a chuck and place it flat on the rotating carrier. Adjust the distance between the cladding equipment and the sample to maintain at 10 mm. Set the running trajectory of the cladding equipment. Set the laser power of the cladding equipment to 1000 W, the scanning speed to 600 mm / min, and the rotation speed of the sample to 100 mm / min. Start laser cladding.

[0048] (7) Sampling: The sample after laser cladding was removed and placed in a drying oven. The temperature was lowered by 50°C every 20 min from 300°C. The sample was kept at room temperature for 10 min each time until it reached room temperature. This formed a wear-resistant and corrosion-resistant iron-based amorphous coating. Its Vickers hardness was measured to be 900.3 HV.

[0049] Example 3

[0050] (1) Prepare the sample: sandblast the sample, then use an ultrasonic cleaning device to clean the sample surface and dry the sample;

[0051] (2) preparing iron-based amorphous composite powder and binder: preparing iron-based amorphous composite powder according to weight percentage, taking 94% of completely amorphous powder and 6% of pure Mo powder and grinding them in a ball mill for 2 h at a speed of 250 r / min, and then taking them out for use;

[0052] Prepare a binder with a composition of 2% phenolic resin, 9% sodium silicate, 4% aluminum dihydrogen phosphate, and the remainder alcohol;

[0053] (3) Preparation of slurry: The slurry composition is: 53% iron-based amorphous composite powder, 47% binder. The prepared slurry is placed in a ball mill and ground for 1 hour at a speed of 250 r / min, and then taken out for use;

[0054] (4) Slurry coating: immerse the sample (ball core) in the slurry, rotate the sample clockwise for 8 seconds and take it out. The slurry coating thickness is 1.5 mm.

[0055] (5) Drying: Place the coated sample in a drying oven at 200°C for 45 min, and then leave it in air for 24 h to allow the coating to dry fully and prevent defects such as bubbles that affect the coating quality during the laser cladding process;

[0056] (6) Cladding: Fix the dried sample with a chuck and place it flat on the rotating carrier. Adjust the distance between the cladding equipment and the sample to maintain it at 10 mm. Set the running trajectory of the cladding equipment. Set the laser power of the cladding equipment to 950 W, the scanning speed to 600 mm / min, and the rotation speed of the sample to 100 mm / min. Start laser cladding.

[0057] (7) Sampling: The sample after laser cladding was removed and placed in a drying oven. The temperature was lowered by 50°C every 18 min from 300°C. The sample was kept at room temperature for 10 min each time until it reached room temperature. Then, the sample was taken out to form a wear-resistant and corrosion-resistant iron-based amorphous coating. The Vickers hardness of the coating was measured to be 982.2 HV.

[0058] The results show that the iron-based amorphous coating prepared by the present invention has a hardness of ≥65HRC, a coating thickness of ≥0.7mm, few micropores and no cracks. The iron-based amorphous composite coating improves the 600°C high-temperature oxidation resistance of the 316 stainless steel substrate by ≥20 times and the conventional corrosion resistance by ≥25 times.

[0059] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A wear-resistant and corrosion-resistant iron-based amorphous coating slurry, characterized in that: The method is composed of the following raw materials by mass fraction: 52-65% of iron-based amorphous composite powder and the rest of the binder; The iron-based amorphous composite powder is obtained by mixing completely amorphous iron-based amorphous powder and Mo powder in a mass ratio of 94-98:2-6.

2. The wear-resistant and corrosion-resistant iron-based amorphous coating slurry according to claim 1, characterized in that: The particle size of the iron-based amorphous composite powder is 15-53 μm; 3. The wear-resistant and corrosion-resistant iron-based amorphous coating slurry according to claim 2, characterized in that: The completely amorphous iron-based amorphous powder is composed of the following elements in mass fraction: 2.2%-2.8% of Cr, 2.2%-2.8% of B, 0.5%-1% of C, 6.4%-7% of Si, and the rest is Fe.

4. The wear-resistant and corrosion-resistant iron-based amorphous coating slurry according to claim 1, characterized in that: The binder is composed of the following raw materials in mass fractions: 1%-5% of phenolic resin, 1%-5% of aluminum dihydrogen phosphate, 5%-10% of sodium silicate, and the rest is alcohol.

5. A method for preparing a wear-resistant and corrosion-resistant iron-based amorphous coating, characterized in that: The following steps are involved: (1) Prepare the sample: sandblast the sample, then use an ultrasonic cleaning device to clean the sample surface and dry the sample; (2) preparing the slurry: preparing the slurry according to the mass fraction of any one of claims 1 to 4, placing the prepared slurry in a ball mill for ball milling, and then taking it out for use; (3) Slurry: immerse the sample in the slurry, rotate the sample for 5-8 seconds and take it out; (4) Drying: Place the coated sample in a drying oven at 200-300°C for 30-45 min, then leave it in the air for 20-24 h to allow the coating to fully dry. (5) Cladding: The dried sample is fixed by a chuck, placed flat on a rotating carrier, and laser cladding is performed using a cladding device; (6) Sampling: After laser cladding, remove the sample and place it in a drying oven. Cool it down by 50°C every 15-20 minutes from 300°C. Keep it warm for 10 minutes each time until it reaches room temperature. Then take it out.

6. The method for preparing a wear-resistant and corrosion-resistant iron-based amorphous coating according to claim 5, characterized in that: In step (2), the ball milling speed is 200-250 r / min, and the ball milling time is 1 h.

7. The method for preparing a wear-resistant and corrosion-resistant iron-based amorphous coating according to claim 5, characterized in that: The slurry coating in step (3) is repeated several times until the slurry coating thickness on the surface of the sample is 1-1.5 mm.

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