Multi-component alloy co-penetrated large-specification mining anti-corrosion chain and manufacturing method thereof

Abstract

The manufacturing method comprises the following steps that S1, a prepared common large-specification mining chain is subjected to sand blasting and cleaning treatment; s2, the treated mining chain is subjected to multi-component alloy co-permeation treatment; s3, oil cooling is conducted on the mining chain subjected to multi-element alloy co-permeation treatment; and S4, the cooled mining chain is subjected to passivation treatment. The method simplifies the process, reduces the raw material and energy consumption cost, improves the corrosion resistance, and has the advantages of high bonding strength, high coating hardness, no hydrogen embrittlement hazard, good coating thickness uniformity and the like. According to the chain manufactured through the method, the organizational structure and performance of the infiltrated layer on the surface of the chain are effectively improved, the hardness of the infiltrated layer is high, and the abrasion resistance is improved by 40% compared with that of a single zinc infiltrated layer.

Description

Technical Field

[0001] The present invention relates to the technical field of mining chains, and particularly to a large-size mining anti-corrosion chain with multi-element alloy co-permeation and a manufacturing method thereof. Background Art

[0002] As an important component for connecting and driving scraper conveyors, mining chains play a crucial role in mining machinery and equipment. However, the coal mine environment is complex and harsh, and mining chains are long-term exposed to harsh working conditions with high humidity, high corrosiveness (such as acidic water environment in mine shafts), and high wear, resulting in easy corrosion and wear on the chain surface. Currently, the mainstream surface treatment anti-corrosion technologies include electro-galvanizing (hot-dip galvanizing), organic coatings, and single-metal permeation layers (such as zinc permeation, aluminum permeation), etc. Although they can delay the corrosion rate of the chain to a certain extent, the effect is limited, and these technologies have the following significant defects:

[0003] Electro-galvanizing: (1) The coating adhesion is weak (≤10 MPa), and it is easy to peel off under dynamic load; (2) The process generates heavy metal-containing wastewater, causing serious environmental pollution.

[0004] Organic coatings: (1) Poor chemical corrosion resistance, blistering and peeling within 3 months in acidic water with pH = 2 - 3 (adhesion ≤5 MPa); (2) Solvent-based coatings release VOCs, not meeting the green mine standard.

[0005] Single-metal permeation layer: (1) The zinc permeation layer has low hardness (≤300 HV) and insufficient wear resistance; (2) The aluminum permeation layer has high brittleness (impact toughness ≤20 J / cm 2 ), easy to crack; (3) The porosity of the permeation layer ≥5%, accelerating the penetration of corrosive media. Summary of the Invention

[0006] To solve the technical problems existing in the above technologies, in view of this, it is necessary to provide a manufacturing method for a large-size mining anti-corrosion chain with multi-element alloy co-permeation.

[0007] A manufacturing method for a large-size mining anti-corrosion chain with multi-element alloy co-permeation includes the following steps:

[0008] Step S1: Sandblasting and cleaning the prepared ordinary large-size mining chain;

[0009] Step S2: Performing multi-element alloy co-permeation treatment on the processed mining chain;

[0010] Step S3: Oil-cooling the mining chain after multi-element alloy co-permeation treatment;

[0011] Step S4: Passivating the cooled mining chain.

[0012] Preferably, the treatment method in step S4 is to soak the cooled mining chain in chromate with a pH value of 3 - 4 for 5 - 8 minutes for passivation treatment.

[0013] Preferably, the treatment method in step S3 is to put the treated mining chain and the infiltration agent formula into a multi - alloy co - infiltration furnace under nitrogen protection for catalytic diffusion, heat up to 380 - 420 °C and keep warm for 2 - 4 hours for multi - alloy co - infiltration treatment.

[0014] Preferably, the infiltration agent formula is: zinc powder: 50% - 60%, aluminum powder: 30% - 40%, rare earth oxide: 5% - 10%.

[0015] Preferably, the sand - blasting treatment method in step S1 is to blast the mining chain with quartz sand of 60 - 80 mesh to ensure that the roughness Ra is controlled within 3.2 - 6.3 μm.

[0016] Preferably, the cleaning treatment method in step S1 is to put the sand - blasted mining chain in acetone solvent and clean it by ultrasonic cleaning for 10 - 15 minutes.

[0017] Preferably, the ordinary large - sized mining chain in step S1 is obtained through the following method:

[0018] (1) Cut the raw materials into short materials of the same length and then braid them into chains;

[0019] (2) Shot - blast and remove rust from the braided chains, and then weld and deburr the rust - removed chains;

[0020] (3) Conduct a primary stretching correction on the welded and deburred chains;

[0021] (4) Heat - treat the chains after the primary stretching using an intermediate - frequency induction furnace;

[0022] (5) Stretch the dimensions and eliminate stress through a secondary stretching process to make ordinary large - sized mining chains.

[0023] Preferably, in step (4), the arc temperature of the quenched chain link is about 990 ± 10 °C, and the straight - edge temperature of the tempered chain link is 520 ± 10 °C.

[0024] Preferably, in step (1), the short materials need to be heated to 850 ± 10 °C during chain braiding.

[0025] It is also necessary to provide a large - sized mining anti - corrosion chain with multi - alloy co - infiltration.

[0026] A large - sized mining anti - corrosion chain with multi - alloy co - infiltration is manufactured by using the manufacturing method of the large - sized mining anti - corrosion chain with multi - alloy co - infiltration described above.

[0027] Compared with the prior art, the multi - element alloy co - permeation large - size mining anti - corrosion chain and its manufacturing method provided by the present invention utilize the theory of metal atom penetration and diffusion. Taking zinc, aluminum powder, etc. as the main raw materials, the heated mining chain workpieces are made to contact with zinc and aluminum powder under vacuum conditions. Through a rather complex physical and chemical reaction process, zinc and aluminum atoms uniformly penetrate into the surface of the mining chain, thus changing the surface composition and forming a dense and uniform intermetallic compound with different zinc - iron ratios - zinc - aluminum - iron alloy co - permeation layer (hereinafter referred to as the co - permeation layer) on the surface of the chain matrix. In addition, adding rare - earth oxides during the co - permeation process can have a certain activation and acceleration effect on the penetration process, thereby effectively improving the organizational structure and performance of the surface permeation layer of the chain. This manufacturing method not only simplifies the process, reduces the raw material and energy consumption costs, but also improves the anti - corrosion performance, and has the advantages of high bonding strength, high coating hardness, no hydrogen embrittlement hazard, good coating thickness uniformity, etc. For the chain manufactured by the present invention, Zn / Al provides basic anti - corrosion, and CeO2 inhibits grain boundary migration through the "pinning effect", with the porosity ≤ 2%; it can enable the chain to form a gradient permeation layer structure: the surface layer (Zn - Al - Ce dense layer, 20 - 30μm), with a hardness ≥ 450HV; the middle layer (diffusion transition layer, 15 - 20μm): a gradient distribution of Al / Zn atoms to inhibit the expansion of corrosion; the bottom layer (matrix bonding layer, 5 - 10μm): metallurgical bonding, with a bonding force ≥ 30MPa. The permeation layer has a high hardness, and the wear resistance is 40% higher than that of a single zinc - permeated layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 This is the static tensile strength test result of the present invention.

[0030] Figure 2 This is the fatigue test result of the present invention.

[0031] Figure 3 This is the test result of the sample of the present invention under the salt spray condition in an alkaline environment.

[0032] Figure 4 This is the test result of a normal link of the comparative example under the salt spray condition in an alkaline environment.

[0033] Figure 5 This is the acid - environment corrosion test result of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Embodiment 1, taking the production of a 48×152 mining C-grade multi-alloy co-permeation anti-corrosion chain product as an example, the material is 23MnNiMoCr54:

[0036] The specific manufacturing method is as follows:

[0037] 1. Blanking, chain knitting, and rust removal:

[0038] For a 48×152 specification chain, the standard straight-edge diameter size is (48±1) mm. Select a material with a diameter of 48.5 mm, cut it into short materials, heat the bar stock to 850 °C, and string the forged vertical rings along the core of the chain knitting mold to form a V-shaped mouth link. The surface of the knitted chain is rust-removed by a chain rust remover.

[0039] 2. Welding and deburring:

[0040] Flash butt welding is performed on the flat ring open ring of the rust-removed chain. After welding, remove the burrs. After removal, the diameter of the welded area ≤ Φ49.5 mm.

[0041] 3. First stretching, heat treatment (quenching, tempering), and second stretching:

[0042] The welded chain is subjected to first stretching on a stretching machine to correct the dimensions and eliminate stress. Then, the 48×152 specification chain after the first stretching is heat-treated in an intermediate frequency heat treatment device (the arc temperature of the quenched link is about 990 °C, and the straight-edge temperature of the tempered link is about 520 °C). The heat-treated chain is subjected to second stretching for sizing and stress elimination to produce a common large-specification mining chain.

[0043] 4. Sandblasting treatment:

[0044] Use quartz sand with a mesh size of 60-80 for sandblasting, and control the roughness within Ra (3.2-6.3) μm to enhance the adsorbing force of the permeating agent; observed by SEM, the bonding force of the permeating layer on the rough surface is increased by 30%.

[0045] 5. Cleaning treatment:

[0046] Place the sandblasted mining chain in an acetone solvent and clean it by ultrasonic cleaning for 10-15 minutes to remove oil stains and fine particles and avoid permeating layer defects.

[0047] 6. Multi-alloy co-permeation treatment:

[0048] Put the cleaned chain into the infiltration agent formula (60% zinc powder, 30% aluminum powder, 10% rare earth oxide, where the rare earth oxide is CeO2), and put it into a multi-alloy co-permeation furnace under nitrogen protection for catalytic diffusion. Heat it to 410 °C and keep it warm for 3 hours for multi-alloy co-permeation treatment. Zinc powder provides cathodic protection, preferentially corrodes the sacrificial anode, aluminum powder forms a dense oxide film (Al2O3) to block the penetration of corrosive media, and Ce 3 + ions are adsorbed on the grain boundaries to inhibit grain coarsening, the grain size ≤ 2 μm, and the porosity ≤ 2%. Catalytic diffusion can reduce the activation energy of Zn / Al atomic diffusion and accelerate the co-permeation rate. Nitrogen protection (purity ≥ 99.99%) prevents oxidation and ensures uniform composition of the permeation layer.

[0049] 7. Post-treatment:

[0050] Place the mine-used chain after multi-alloy co-permeation treatment in oil for cooling, and then carry out a sealing treatment. Place the cooled chain in chromate with pH = 3 - 4 and soak it for 5 - 8 minutes for passivation treatment to form a Cr(OH)3 / Cr2O3 composite film to fill the micropores, and finally form a finished multi-alloy co-permeation chain.

[0051] Example 2, taking the manufacture of 48×152 mine-used Class C multi-alloy co-permeation anti-corrosion chain products as an example, the material is 23MnNiMoCr54:

[0052] The specific manufacturing method is as follows.

[0053] 1. Blanking, chain knitting, and rust removal:

[0054] For the 48×152 specification chain, the standard straight-edge diameter size is (48 ± 1) mm. Select a material with a diameter of 48.5 mm, cut it into short materials, heat the bar to 840 °C, and string the forged vertical rings along the core of the chain knitting mold to form a V-shaped mouth link. Carry out surface rust removal on the knitted chain through a chain rust removal machine.

[0055] 2. Welding and deburring:

[0056] Flash butt weld the flat ring open ring of the rust-removed chain, and remove the burrs after welding. The diameter of the welded area after removal ≤ Φ49.5 mm.

[0057] 3. First stretching, heat treatment (quenching, tempering), and second stretching:

[0058] The welded chain is subjected to one-time stretching to correct the dimensions and eliminate stress on a stretching machine. Then, the 48×152 specification chain after one-time stretching is heat-treated in an intermediate frequency heat treatment equipment (the arc temperature of the quenched link is about 980 °C, and the straight edge temperature of the tempered link is about 510 °C). After heat treatment, the chain is subjected to secondary stretching to correct the dimensions and eliminate stress, and a common large-specification mining chain is made.

[0059] 4. Sandblasting treatment:

[0060] Quartz sand with a mesh size of 60 - 80 is used for sandblasting, and the roughness is controlled at Ra (3.2 - 6.3) μm to enhance the adsorbing force of the infiltration agent; observed by SEM, the bonding force of the infiltration layer on the rough surface is increased by 30%.

[0061] 5. Cleaning treatment:

[0062] The mining chain after sandblasting treatment is placed in acetone solvent and cleaned by ultrasonic cleaning for 10 - 15 minutes to remove oil stains and fine particles, avoiding defects in the infiltration layer.

[0063] 6. Multi - alloy co - infiltration treatment:

[0064] The cleaned chain is put into an infiltration agent formula (60% zinc powder, 30% aluminum powder, 10% rare earth oxide, where the rare earth oxide is CeO2), and is placed in a multi - alloy co - infiltration furnace under nitrogen protection for catalytic diffusion. It is heated to 380 °C and kept warm for 2 hours for multi - alloy co - infiltration treatment. Zinc powder provides cathodic protection and preferentially corrodes the sacrificial anode. Aluminum powder forms a dense oxide film (Al2O3) to block the penetration of corrosive media. The Ce 3 + ions in the rare earth oxide are adsorbed on the grain boundaries to inhibit grain coarsening, the grain size ≤ 2 μm, and the porosity ≤ 2%. Catalytic diffusion can reduce the diffusion activation energy of Zn / Al atoms and accelerate the co - infiltration rate. Nitrogen protection (purity ≥ 99.99%) prevents oxidation and ensures the uniformity of the infiltration layer composition.

[0065] 7. Post - treatment:

[0066] The mining chain after multi - alloy co - infiltration treatment is placed in oil for cooling, and oil cooling increases the surface hardness (≥ 450 HV); then, it is subjected to a sealing treatment. The cooled chain is placed in chromate with pH = 3 - 4 and soaked for 5 - 8 minutes for passivation treatment to form a Cr(OH)3 / Cr2O3 composite film to fill the micropores, and finally a finished multi - alloy co - infiltration chain is formed.

[0067] Example 3, taking the production of a 48×152 mining C - grade multi - alloy co - infiltration anti - corrosion chain product as an example, the material is 23MnNiMoCr54:

[0068] The specific manufacturing method is as follows,

[0069] 1. Blanking, chain braiding, rust removal:

[0070] For the 48×152 specification chain, the standard straight-edge diameter size is (48±1)mm. Select materials with a diameter of 48.5mm, cut them into short materials, heat the bar stock to 860°C, and string and braid the forged vertical rings along the core of the chain-braiding mold to form a chain link with a V-shaped upper opening. Then, surface rust removal of the braided chain is performed through a chain rust removal machine.

[0071] 2. Welding, deburring:

[0072] Flash butt welding is performed on the flat ring opening ring of the rust-removed chain. After welding, burrs are removed, and the diameter of the welded area after removal is ≤Φ49.5mm.

[0073] 3. First stretching, heat treatment (quenching, tempering), second stretching:

[0074] The welded chain is subjected to first stretching on a stretching machine to correct the dimensions and eliminate stress. Then, the 48×152 specification chain after the first stretching is heat-treated in an intermediate frequency heat treatment equipment (the arc temperature of the quenched chain link is about 1000°C, and the straight-edge temperature of the tempered chain link is about 530°C). After heat treatment, the chain is subjected to second stretching for sizing and stress elimination to make a common large-specification mining chain.

[0075] 4. Sandblasting treatment:

[0076] Quartz sand with 60 - 80 mesh is used for sandblasting, and the roughness is controlled at Ra(3.2 - 6.3)μm to enhance the adsorbing force of the infiltrant; observed by SEM, the bonding force of the infiltration layer on the rough surface is increased by 30%.

[0077] 5. Cleaning treatment:

[0078] The mining chain after sandblasting treatment is placed in an acetone solvent and cleaned by ultrasonic cleaning for 10 - 15 minutes to remove oil stains and fine particles and avoid infiltration layer defects.

[0079] 6. Multi-element alloy co-infiltration treatment:

[0080] The cleaned chain is put into an infiltrant formula (60% zinc powder, 30% aluminum powder, 10% rare earth oxide, where the rare earth oxide uses CeO2), and is placed in a multi-element alloy co-infiltration furnace under nitrogen protection for catalytic diffusion. The temperature is raised to 420°C and held for 4 hours for multi-element alloy co-infiltration treatment. Zinc powder provides cathodic protection and preferentially corrodes the sacrificial anode. Aluminum powder forms a dense oxide film (Al2O3) to block the penetration of corrosive media. Ce in the rare earth oxide 3Positive ions are adsorbed on the grain boundaries, inhibiting grain coarsening. The grain size is ≤2 μm and the porosity is ≤2%. Catalytic diffusion can reduce the activation energy of Zn / Al atomic diffusion and accelerate the co-permeation rate. Nitrogen protection (purity ≥99.99%) prevents oxidation and ensures uniform composition of the permeated layer.

[0081] 7. Post-treatment:

[0082] The mined chain after multi-alloy co-permeation treatment is placed in oil for cooling, and then undergoes a sealing treatment. The cooled chain is placed in chromate with a pH of 3 - 4 and soaked for 5 - 8 minutes for passivation treatment to form a Cr(OH)3 / Cr2O3 composite film, filling the micropores, and finally forming the finished multi-alloy co-permeation chain.

[0083] Comparative example:

[0084] Using 23MnNiMoCr54 material, a 48×152 mined C-class chain is manufactured using the existing technology as a normal chain. The specific process method is the existing technology and will not be elaborated here again.

[0085] Take 2 five-ring chains manufactured in the examples for static tensile strength inspection. The inspection results are shown in Table 1, Figure 1 as shown; take 1 three-ring chain manufactured in the examples for fatigue inspection. The inspection results are as Figure 2 shown, indicating that the above chains meet the mechanical property requirements of the 48×152 specification chains with a quality grade of C in the GB / T 12718-2009 "High-strength Round Link Chains for Mining" standard and the MT / T 929-2004 standard. The reference standard is shown in Table 1:

[0086] Table 1

[0087]

[0088] Take 1 single-ring chain manufactured in the examples and 1 single-ring chain manufactured in the comparative example for a salt spray test in an alkaline environment. Test method: GB / T 10125-2021, test equipment: salt spray test chamber, test conditions: collected brine concentration: 50 g / L ± 5 g / L, salt spray chamber temperature: 35°C ± 2°C, brine sedimentation rate: 1.5 mL / h ± 0.5 mL / h, pH value: 6.5 - 7.2, salt spray test for 72 hours on the sample. The test results are as Figure 3 、 Figure 4 shown. A large amount of white rust is generated on the multi-alloy co-permeated chain link, and the mass loss rate is ≤10 g / m 2 , a large amount of red rust is generated on the normal chain link, and the mass loss rate > 10 g / m 2 .

[0089] Take one single-loop chain manufactured in the example and one single-loop chain manufactured in the comparative example for the acid environment corrosion test. Simulate soaking in the acid environment with pH = 4.8 - 5.5 in the mine for 11 months. The test results are as follows Figure 5 shown. After comparison, less red rust is generated on the multi-alloy co-permeated chain links, and more red rust is generated on the normal chain links. The mass loss of the multi-alloy co-permeated chain links ≤ 0.5 mg / cm 2 , and the mass loss of the normal chain links > 0.5 mg / cm 2 .

[0090] Take one single-loop chain manufactured in the example for inspection. After inspection, the penetration layer thickness of the multi-alloy co-permeated chain link is 51 μm, and the surface hardness is 460 HV.

[0091] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A manufacturing method for a large-sized anti-corrosion mining chain with multi-element alloy co-permeation, characterized in that: Including the following steps, Step S1: Sandblast and clean the prepared ordinary large-sized mining chains; Step S2: Perform multi-element alloy co-permeation treatment on the treated mining chains; Step S3: Oil-cool the mining chains after multi-element alloy co-permeation treatment; Step S4: Passivate the cooled mining chains.

2. The manufacturing method of a large-sized mining anti-corrosion chain with multi-element alloy co-permeation according to claim 1, characterized in that: The treatment method of Step S4 is to soak the cooled mining chains in chromate with a pH value of 3-4 for 5-8 minutes for passivation treatment.

3. The manufacturing method of a large-size mining anti-corrosion chain with multi-element alloy co-permeation according to claim 2, characterized in that: The treatment method of Step S3 is to put the treated mining chains and the infiltration agent formula into a multi-element alloy co-permeation furnace under nitrogen protection for catalytic diffusion, heat up to 380-420°C and keep it warm for 2-4 hours for multi-element alloy co-permeation treatment.

4. The manufacturing method of the large-sized anti-corrosion mining chain with multi-element alloy co-permeation according to claim 3, characterized in that: The infiltration agent formula is: zinc powder: 50%-60%, aluminum powder: 30%-40%, rare earth oxide: 5%-10%.

5. The manufacturing method of a large-sized mining anti-corrosion chain with multi-element alloy co-permeation according to claim 4, characterized in that: The sandblasting treatment method of Step S1 is to sandblast the mining chains with quartz sand of 60-80 mesh to ensure that the roughness Ra is controlled within 3.2-6.3μm.

6. The manufacturing method of the large-size mining anti-corrosion chain with multi-element alloy co-permeation according to claim 5, characterized in that: The cleaning treatment method of Step S1 is to place the sandblasted mining chains in acetone solvent and clean them by ultrasonic cleaning for 10-15 minutes.

7. The manufacturing method of the large-sized mining anti-corrosion chain with multi-alloy co-permeation according to claim 1, characterized in that: The ordinary large-sized mining chains in Step S1 are obtained through the following methods: (1) Cut the raw materials into short materials of the same length and then braid them into chains; (2) Shot blast and remove rust from the braided chains, and then weld and deburr the rust-removed chains; (3) Perform primary stretching and straightening on the welded and deburred chains; (4) Heat-treat the chains after primary stretching using an intermediate frequency induction furnace; (5) Stretch the size and eliminate stress through a secondary stretching process to make ordinary large-sized mining chains.

8. The manufacturing method of a large-sized anti-corrosion mining chain with multi-element alloy co-permeation according to claim 7, characterized in that: In Step (4), the arc temperature of the quenched chain links is about 990±10°C, and the straight-edge temperature of the tempered chain links is 520±10°C.

9. The manufacturing method of the large-sized mining anti-corrosion chain with multi-element alloy co-permeation according to claim 7, characterized in that: In Step (1), the short materials need to be heated to 850±10°C during chain braiding.

10. A large-sized mining anti-corrosion chain with multi-element alloy co-permeation, characterized in that: Manufactured by using the manufacturing method of the multi-element alloy co-permeation large-sized mining anti-corrosion chain described in any one of claims 1-9.

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