Corrosion-resistant anchor rod and method of manufacturing the same

Abstract

The application discloses a kind of corrosion-resistant anchor rod and manufacturing method thereof, it is related to metal corrosion protection field, can improve the corrosion resistance of anchor rod.The composition and mass percentage of anchor rod body include:Fe 94.36%~95.27%, C 0.111~0.134%, Cu 0.2~0.4%, Si 0.3~0.34%, Mn 0.74~0.88%, Ni 1.37~1.55%, Cr 1.84~2.04%, Mo 0.06~0.12%, V 0.07~0.09%;The composition and mass percentage of antimicrobial corrosion coating include:water-based epoxy resin 57%~78%, nano-ZnO 3%~5%, Sb-doped nano-ZnO 2%~3%, nano-TiO2 2%~3%, flaky mica powder 4%~6%.The anchor rod of the application is suitable for the occasion of downhole support.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal corrosion protection, and particularly relates to a corrosion-resistant anchor rod and a manufacturing method thereof. BACKGROUND

[0002] The anchor rod is a commonly used supporting material in the underground coal mine, and is widely applied to maintaining the stability of the roadway due to its excellent anchoring performance. During the service of the anchor rod in the underground mine, the anchor rod is prone to brittle fracture under the action of stress, corrosive ions, microorganisms and other factors, and the fracture strength of the anchor rod is far lower than the failure strength. The reason for the brittle fracture of the anchor rod is that the stress corrosion cracking occurs in the anchor rod, and the microorganisms are an important factor affecting the stress corrosion of the anchor rod.

[0003] The microorganisms affecting the corrosion of the anchor rod in the underground coal mine mainly include sulfate-reducing bacteria, nitrate-reducing bacteria, acid-producing bacteria, sulfur-oxidizing bacteria and iron-oxidizing bacteria. The corrosion of the microorganisms to the anchor rod is a multi-field coupling process of bio-community driven electrochemistry-biochemistry-mechanics. Firstly, the microorganisms adhere to the anchor rod surface to form a biological membrane; then the direct corrosion of the metabolic products of the microorganisms occurs, such as the reaction of hydrogen sulfide generated by the sulfate-reducing bacteria and iron to promote the anode dissolution, and the acid generated by the metabolism of the acid-producing bacteria to destroy the passivation film of the anchor rod; then the more hidden bio-electrochemical corrosion occurs, in which the microorganisms directly steal metal electrons to accelerate the anode dissolution; finally, the stress synergy effect cannot be ignored, in which the stress gradient promotes the hydrogen atoms to penetrate into the anchor rod lattice to cause hydrogen embrittlement, the stress concentration points are formed under the pitting corrosion pits of the biological membrane to promote the crack initiation and accelerate the crack propagation.

[0004] The premature fracture of the anchor rod caused by the microbial corrosion seriously threatens the safety and stability of the roadway of the coal mine, however, the existing anchor rod and the related corrosion prevention measures cannot effectively prevent the corrosion of the microorganisms to the anchor rod. Therefore, it is urgent to provide a technical solution for the above-mentioned technical problems of the prior art. SUMMARY

[0005] Therefore, the present application provides a corrosion-resistant anchor rod and a manufacturing method thereof, which can effectively resist the corrosion of the microorganisms to the anchor rod.

[0006] In a first aspect, an embodiment of the present application provides a corrosion-resistant anchor rod, comprising: a rod body and an anti-microbial corrosion coating layer coated on the surface of the rod body.

[0007] The composition and mass percentage of the rod body are as follows: Fe 94.36%-95.27%, C 0.111-0.134%, Cu 0.2-0.4%, Si 0.30-0.34%, Mn 0.74-0.88%, Ni 1.37-1.55%, Cr 1.84-2.04%, Mo 0.06-0.12%, V 0.07-0.09%, W 0.005-0.015%, Co 0.03-0.05%, P≤0.026%, and S≤0.003%.

[0008] The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 58%-77%, nano-ZnO 3%-5%, Sb-doped nano-ZnO 2%-3%, nano-TiO2 2%-3%, flaky mica powder 4%-6%, silane coupling agent 10%-25%, polyether-modified siloxane 0.3%-0.5%, mineral oil antifoam 0.2%-0.3%, and sucrose ester dispersant 0.5%-1%; wherein, in the Sb-doped nano-ZnO, Zn / Sb=10:1.

[0009] Optionally, the particle sizes of the nano-ZnO and nano-TiO2 are 20-40 nm respectively; and the aspect ratio of the flaky mica powder is greater than 50.

[0010] The composition and mass percentage of the rod body are as follows: Fe 94.7%, C 0.124%, Cu 0.27%, Si 0.32%, Mn 0.84%, Ni 1.55%, Cr 1.94%, Mo 0.08%, V 0.07%, W 0.01%, Co 0.04%, P 0.024%, and S 0.002%.

[0011] The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 65%, nano-ZnO with a particle size of 20-40 nm 4%, Sb-doped nano-ZnO 2%, nano-TiO2 2%, flaky mica powder 4%, silane coupling agent 21.1%, polyether-modified siloxane 0.5%, mineral oil antifoam 0.3%, and sucrose ester dispersant 1%.

[0012] The composition and mass percentage of the rod body are as follows: Fe 95.1%, C 0.114%, Cu 0.35%, Si 0.3%, Mn 0.74%, Ni 1.37%, Cr 1.84%, Mo 0.06%, V 0.07%, W 0.005%, Co 0.03%, P 0.014%, and S 0.001%.

[0013] The composition and mass percentage of the anti-microbial corrosion coating are: water-based epoxy resin 70%, nano-ZnO with a particle size of 20-40 nm 5%, Sb-doped nano-ZnO 3%, nano-TiO2 2%, flaky mica powder 6%, silane coupling agent 12%, polyether modified siloxane 0.5%, mineral oil defoaming agent 0.2%, sucrose ester dispersant 0.5%.

[0014] Optionally, the composition and mass percentage of the rod body are: Fe 94.5%, C 0.111%, Cu 0.25%, Si 0.30%, Mn 0.74%, Ni 1.37%, Cr 1.84%, Mo 0.06%, V 0.07%, W 0.005%, Co 0.03%, P 0.026%, S 0.003%;

[0015] The composition and mass percentage of the anti-microbial corrosion coating are: water-based epoxy resin 77%, nano-ZnO 3%, Sb-doped nano-ZnO 2%, nano-TiO2 2%, flaky mica powder 4%, silane coupling agent 10.8%, polyether modified siloxane 0.3%, mineral oil defoaming agent 0.2%, sucrose ester dispersant 0.5%.

[0016] Optionally, the composition and mass percentage of the rod body are: Fe 94.4%, C 0.134%, Cu 0.3%, Si 0.34%, Mn 0.88%, Ni 1.55%, Cr 2.04%, Mo 0.12%, V 0.09%, W 0.015%, Co 0.05%, P 0.012%, S 0.001%;

[0017] The composition and mass percentage of the anti-microbial corrosion coating are: water-based epoxy resin 60%, nano-ZnO 5%, Sb-doped nano-ZnO 3%, nano-TiO2 3%, flaky mica powder 6%, silane coupling agent 21%, polyether modified siloxane 0.5%, mineral oil defoaming agent 0.3%, sucrose ester dispersant 1%.

[0018] Optionally, the anti-microbial corrosion coating can also be used in the anti-corrosion measures of anchor cables.

[0019] In a second aspect, embodiments of the present application provide a manufacturing method of the corrosion-resistant anchor rod according to any one of the preceding embodiments, comprising the following steps:

[0020] a. Steel billet smelting, prepared according to the preset mass percentage of each component, molten iron, scrap steel, alloy, limestone smelting, maintaining the end point carbon content of 0.111~0.134%, limestone for slagging desulfurization and dephosphorization, so that the phosphorus content in the molten steel is maintained below 0.026%, the sulfur content is maintained below 0.003%, and the refined molten steel is obtained at 1650~1680℃;

[0021] b. Continuous casting, pouring the refined molten steel into a mold for continuous casting, cooling the billet at a cooling water amount of 0.8~1.2L / kg steel and a drawing speed of 1.8~2.2m / min, and detecting the billet defects after cooling, eliminating the defective billets;

[0022] c. Hot rolling, placing the detected billet into a heating furnace for pretreatment, heating temperature 1150~1250℃, soaking time≥120min, oxygen content in the furnace≤0.5%; the pretreated continuous casting billet is sequentially subjected to rough rolling into a rod with a diameter of 60mm, water cooling, and finish rolling into a left-handed non-longitudinal rib screw thread steel with a diameter of 18~25mm;

[0023] d. Rod body finishing, cutting the finish-rolled screw thread steel into specified lengths by using a hydraulic cold shearing machine, ensuring that the cutting inclination is≤1°, straightening the screw thread steel by using a multi-roll reverse bending straightening process, ensuring that the straightness of the screw thread steel is≤1mm / m, and cold rolling the threads at the end of the screw thread steel by using a three-axis thread rolling machine;

[0024] e. Coating preparation, mixing nano-ZnO, Sb-ZnO, and TiO2 according to a predetermined ratio, adding a predetermined proportion of silane coupling agent, then immersing the dry powder in anhydrous ethanol with a liquid-solid mass ratio of 3:1, ultrasonic treatment at 60℃ and a power of 200W for 1h, and then sequentially performing suction filtration, drying at 80℃, and crushing through a 400 mesh sieve to obtain a nano-powder mixture; adding the nano-powder mixture, flaky mica powder, sucrose ester dispersant, water-based epoxy resin, polyether modified siloxane, and mineral oil defoaming agent into a reaction kettle according to a predetermined ratio for melting, ultrasonic stirring, and mechanical stirring to obtain an anti-microbial corrosion coating with a final viscosity of 90~110cP and a particle size distribution of D50=85±10nm;

[0025] f. Rod body surface spraying of coating, sequentially performing sand blasting, rust removal, and oil removal on the rod body, preheating at 60℃ for 1h, and uniformly spraying the anti-microbial corrosion coating on the surface of the rod body by using an electrostatic spraying process.

[0026] Optionally, in step a, the molten iron, scrap steel, alloy, limestone are smelted, and the proportions of the components are adjusted to ensure that the composition and mass percentage in the molten steel are: Fe 94.36%~95.27%, C 0.111~0.134%, Cu 0.2~0.4%, Si 0.30~0.34%, Mn 0.74~0.88%, Ni 1.37~1.55%, Cr 1.84~2.04%, Mo 0.06~0.12%, V 0.07~0.09%, W 0.005~0.015%, Co 0.03~0.05%, P ≤0.026%, S ≤0.003%, to obtain refined molten steel.

[0027] Optionally, in step e, the nano-powder mixture, flaky mica powder, sucrose ester dispersant, water-based epoxy resin, polyether modified siloxane and mineral oil defoaming agent are added into the reaction kettle in a predetermined proportion for melting, ultrasonic stirring and mechanical stirring, and the components are adjusted to ensure that the composition and mass percentage in the coating are: water-based epoxy resin 58%~77%, nano-ZnO 3%~5%, Sb-doped nano-ZnO 2%~3%, nano-TiO2 2%~3%, flaky mica powder 4%~6%, silane coupling agent 10%~25%, polyether modified siloxane 0.3%~0.5%, mineral oil defoaming agent 0.2%~0.3%, sucrose ester dispersant 0.5%~1%.

[0028] Optionally, in step f, the rod body is sequentially subjected to sand blasting, rust removal and oil removal, and the specific operation is that the rod body is subjected to rust removal by using a sand blasting rust removal process, and the surface roughness Ra of the rod body is ensured to be 40~60μm, so as to enhance the adhesion of the coating, and the oil removal is performed by spraying the rod body with an alkaline cleaning agent with pH=9.5 at 60℃ for 3min, then rinsing the rod body with deionized water and blowing the rod body dry with compressed air, so that the surface of the rod body is kept dry, clean and pollution-free.

[0029] The corrosion-resistant anchor rod and the manufacturing method thereof provided by the embodiment of the application add alloy elements that effectively inhibit microorganisms in the rod body manufacturing process, adjust the composition of the anchor rod, coat the surface of the rod body with an antimicrobial corrosion-resistant coating containing nano-ZnO bacteriostatic material, and adjust the components of the coating, so as to ensure that the coating has good coating performance and inhibits the corrosion of various microorganisms in the wellbore on the anchor rod; the application improves the corrosion resistance of the anchor rod while ensuring the mechanical properties of the anchor rod, can not only inhibit the adhesion of microorganisms, but also block the electrochemical corrosion chain, ensures the service safety of the anchor rod in the process of supporting the coal mine roadway, and solves the serious problem of corrosion of the existing anchor rod by microorganisms in the wellbore. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative work.

[0031] Figure 1 It is a physical picture of the coated anchor rod in the embodiment 5 of the present application, wherein the white wrapping material on the surface of the anchor rod is the anti-microbial corrosion coating containing the nano-ZnO bacteriostatic material;

[0032] Figure 2 It is a scanning electron microscope picture of long-term corrosion of the embodiment, wherein (a) is the morphology of corrosion for 100 days of the embodiment 5, and (b) is the morphology of corrosion for 100 days of the comparative example. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0034] It should be clear that the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0035] The embodiments of the present application aim to provide a corrosion-resistant anchor rod and a manufacturing method thereof, which can effectively resist the corrosion problem of the anchor rod caused by microorganisms.

[0036] In the first aspect, the embodiments of the present application provide a corrosion-resistant anchor rod, comprising: a rod body and an anti-microbial corrosion coating coated on the surface of the rod body.

[0037] The composition and mass percentage of the rod body are as follows: Fe 94.36%~95.27%, C 0.111~0.134%, Cu 0.2~0.4%, Si 0.30~0.34%, Mn 0.74~0.88%, Ni 1.37~1.55%, Cr 1.84~2.04%, Mo 0.06~0.12%, V 0.07~0.09%, W 0.005~0.015%, Co 0.03~0.05%, P ≤0.026%, S ≤0.003%.

[0038] The composition and mass percentage of the antimicrobial corrosion coating are as follows: 58%~77% waterborne epoxy resin, 3%~5% nano ZnO, 2%~3% Sb-doped nano ZnO, 2%~3% nano TiO2 (rutile type), 4%~6% flake mica powder, 10%~25% silane coupling agent, 0.3%~0.5% polyether-modified siloxane, 0.2%~0.3% mineral oil defoamer, and 0.5%~1% sucrose ester dispersant; wherein, in the Sb-doped nano ZnO, Zn / Sb = 10:1.

[0039] In some embodiments, the particle sizes of the nano-ZnO and nano-TiO2 are 20~40nm respectively; the aspect ratio of the flake mica powder is >50.

[0040] The roles of key elements in corrosion-resistant anchor bolts with anti-corrosion coatings:

[0041] Cu: The core component for resisting microbial corrosion; Cu is released during the service of the anchor bolt. 2+ It disrupts the cell membranes of sulfate-reducing bacteria and other microorganisms, enhancing the antibacterial rate while reducing the corrosion rate in environments with pH 3 to 6. Simultaneously, the nanoscale Cu-rich phase pins dislocations, which can improve the hardness of anchor bolts.

[0042] Cr: A dense Cr2O3 passivation film is formed on the surface of the anchor rod, which blocks the penetration of microorganisms and corrosive media, enhances salt spray resistance, and significantly reduces the microbial adhesion rate compared with ordinary mining anchor rods. At the same time, it can shrink the austenite region, promote the formation of ferrite phase, refine the grains, and increase the yield strength of the anchor rod.

[0043] Ni: Repairs the passivation film on anchor bolts, enhances austenite stability, shifts the pitting potential to the positive, resists corrosion from nitrate-reducing bacteria and their acidic metabolic environment, while also increasing the toughness and impact strength of anchor bolts and preventing the propagation of corrosion cracks.

[0044] Mo: Inhibits Cl - The localized corrosion caused by the bacteria resists the sulfides produced by sulfate-reducing bacteria metabolism, generates carbides Mo2C to delay sensitization, and inhibits the tendency of intergranular corrosion.

[0045] V: Captures hydrogen atoms produced by nitrate-reducing bacteria, reducing the hydrogen diffusion coefficient, increasing anchor rod hardness, and decreasing wear rate. At the same time, carbide VC can refine grains and block corrosion channels.

[0046] W: It suppresses strength softening under high downhole temperatures (>60℃) and has a high high-temperature yield strength retention rate. Carbide W2C can stabilize martensitic laths and prevent temper brittleness.

[0047] Co: Accelerate the regeneration of Cr2O3, inhibit the formation of iron oxidizing bacteria, interfere with microbial electron transport chain, and improve the antibacterial rate with Cu, while inhibiting the anchoring organization phase change, delaying the γ→α transformation, and improving the stability of reversed austenite.

[0048] C: Solid solution strengthening, increase the tensile strength of the anchor rod by 300~400MPa, carbon content >0.15% causes intergranular corrosion, carbon content <0.10% leads to insufficient strength, while carbon content of 0.111~0.134% can form fine MC carbide with V / Mo, rather than harmful Cr 23 C6.

[0049] Mn: Can deoxidize and fix sulfur to form harmless spherical MnS, prevent sulfur segregation to initiate corrosion, and assist Ni to expand the γ phase region, improve quenching property, and promote austenite stability.

[0050] Si: Form SiO2 internal oxidation layer, block penetration, resist organic acids produced by acid-producing bacteria metabolism, and enhance the continuity of corrosion-resistant phase of anchor rod matrix.

[0051] P, S: Impurities, control the upper limit of P and S content, reduce P grain boundary segregation and decrease hydrogen brittleness sensitivity of anchor rod; S upper limit control can avoid MnS chain inclusions and reduce microbial corrosion initiation points.

[0052] The role of each component in the antimicrobial corrosion coating:

[0053] Waterborne epoxy resin: Main component of the coating, provides adhesion and mechanical strength, when the waterborne epoxy resin content is >70%, the flexibility of the coating decreases; when the waterborne epoxy resin content is <50%, the coating is not wrapped enough.

[0054] Nano ZnO (particle size 20~40nm): Release destroy microbial cell membranes, can inhibit or kill a variety of different types of bacteria, has a high killing rate for sulfate-reducing bacteria and nitrate-reducing bacteria, particle size ≤40nm, specific surface area ≥50m 2 / g, can improve the ion release rate.

[0055] Sb-doped nano-ZnO (Zn / Sb=10:1): Enhance the antibacterial ability of the coating in dark environment.

[0056] Nano TiO2 (rutile type): Form heterojunction with ZnO to synergistically resist bacteria, while delaying resin aging, rutile type is more stable than anatase type.

[0057] Flaky mica powder (aspect ratio >50): Form a physical barrier to enhance the wear resistance of the coating.

[0058] Silane coupling agent: bridge between anchor rod and coating interface, enhance the corrosion resistance of the coating.

[0059] Polyether modified siloxane: control the flow properties of the coating on the anchor rod surface, reduce the surface tension, reduce the foam generation.

[0060] Mineral oil defoamer: eliminate foam during coating production and spraying process, ensure the uniformity of the anchor rod surface coating and the protection ability.

[0061] Sucrose ester dispersant: ensure the stable dispersion of nanoparticles, slow release of Zn in the coating 2+ , long duration of antibacterial activity.

[0062] The corrosion-resistant anchor rod with anti-corrosion coating provided by the embodiment of the present application adds alloy elements that effectively inhibit microorganisms during the manufacturing process of the rod body, adjusts the composition of the anchor rod, and on the other hand, applies an anti-microbial corrosion coating containing a nano-ZnO bacteriostatic material on the surface of the rod body, and adjusts the composition of the coating to ensure that the coating has good coating performance while inhibiting the corrosion of various microorganisms in the well on the anchor rod. The present application improves the corrosion resistance of the anchor rod while ensuring the mechanical properties of the anchor rod, not only inhibits the adhesion of microorganisms, but also blocks the electrochemical corrosion chain, ensures the service safety of the anchor rod in the process of coal mine roadway support, and solves the serious problem of corrosion of the existing anchor rod by microorganisms in the well.

[0063] The specific embodiments of the corrosion-resistant anchor rod with anti-corrosion coating of the present application are as follows: Embodiment 1

[0064] A corrosion-resistant anchor rod, comprising: a rod body and an anti-microbial corrosion coating applied on the surface of the rod body.

[0065] The composition and mass percentage of the rod body are as follows: Fe 94.7%, C 0.124%, Cu 0.27%, Si 0.32%, Mn 0.84%, Ni 1.55%, Cr 1.94%, Mo 0.08%, V 0.07%, W 0.01%, Co 0.04%, P 0.024%, and S 0.002%.

[0066] The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 65%, nano-ZnO (particle size 20-40 nm) 4%, Sb-doped nano-ZnO (Zn / Sb=10:1) 2%, nano-TiO2 (rutile type) 2%, flaky mica powder (diameter-thickness ratio>50) 4%, silane coupling agent 21.1%, polyether modified siloxane 0.5%, mineral oil defoamer 0.3%, and sucrose ester dispersant 1%.

[0067] Embodiment 2

[0068] A corrosion-resistant anchor rod comprises a rod body and an anti-microbial corrosion coating coated on the surface of the rod body;

[0069] The composition and mass percentage of the rod body are as follows: Fe 95.1%, C 0.114%, Cu 0.35%, Si 0.3%, Mn 0.74%, Ni 1.37%, Cr 1.84%, Mo 0.06%, V 0.07%, W 0.005%, Co 0.03%, P 0.014%, and S 0.001%.

[0070] The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 70%, nano-ZnO (particle size 20-40 nm) 5%, Sb-doped nano-ZnO (Zn / Sb=10:1) 3%, nano-TiO2 (rutile type) 2%, flaky mica powder (diameter-thickness ratio>50) 6%, silane coupling agent 12%, polyether-modified siloxane 0.5%, mineral oil-based defoaming agent 0.2%, and sucrose ester dispersant 0.5%.

[0071] Embodiment 3

[0072] A corrosion-resistant anchor rod comprises a rod body and an anti-microbial corrosion coating coated on the surface of the rod body;

[0073] The composition and mass percentage of the rod body are as follows: Fe 94.5%, C 0.111%, Cu 0.25%, Si 0.30%, Mn 0.74%, Ni 1.37%, Cr 1.84%, Mo 0.06%, V 0.07%, W 0.005%, Co 0.03%, P 0.026%, and S 0.003%.

[0074] The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 77%, nano-ZnO 3%, Sb-doped nano-ZnO (Zn / Sb=10:1) 2%, nano-TiO2 (rutile type) 2%, flaky mica powder 4%, silane coupling agent 10.8%, polyether-modified siloxane 0.3%, mineral oil-based defoaming agent 0.2%, and sucrose ester dispersant 0.5%.

[0075] Embodiment 4

[0076] A corrosion-resistant anchor rod comprises a rod body and an anti-microbial corrosion coating coated on the surface of the rod body;

[0077] The composition and mass percentage of the rod body are as follows: Fe 94.4%, C 0.134%, Cu 0.3%, Si 0.34%, Mn 0.88%, Ni 1.55%, Cr 2.04%, Mo 0.12%, V 0.09%, W 0.015%, Co 0.05%, P 0.012%, and S 0.001%.

[0078] The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 60%, nano-ZnO 5%, Sb-doped nano-ZnO (Zn / Sb=10:1) 3%, nano-TiO2 (rutile type) 3%, flaky mica powder 6%, silane coupling agent 21%, polyether-modified siloxane 0.5%, mineral oil defoaming agent 0.3%, and sucrose ester dispersant 1%.

[0079] In a second aspect, the embodiment of the present application further provides a manufacturing method of the corrosion-resistant anchor rod, which comprises the following steps:

[0080] a. Steel billet smelting: smelting molten iron, scrap steel, alloy and limestone prepared according to the preset mass percentage of each component, maintaining the end-point carbon content at 0.111-0.134%, limestone for slagging desulfurization and dephosphorization, maintaining the phosphorus content in the molten steel below 0.026% and the sulfur content below 0.003%, and obtaining refined molten steel at 1650-1680°C;

[0081] b. Continuous casting: pouring the refined molten steel into a mold for continuous casting, cooling the steel billet at a cooling water amount of 0.8-1.2 L / kg steel and a drawing speed of 1.8-2.2 m / min, and detecting the defects of the billet after cooling to eliminate the defective billets;

[0082] c. Hot rolling: placing the detected steel billet into a heating furnace for pretreatment, heating at a temperature of 1150-1250°C and for a soaking time of ≥120 min, and maintaining the oxygen content in the furnace at ≤0.5%; sequentially performing rough rolling into a bar with a diameter of 60 mm, water cooling and fine rolling into left-handed non-longitudinal rib screw thread steel with a diameter of 18-25 mm;

[0083] d. Rod body finishing: cutting the fine-rolled screw thread steel into specified lengths by using a hydraulic cold shearing machine, ensuring that the inclination of the cut is ≤1°, straightening the screw thread steel by using a multi-roll reverse bending straightening process, ensuring that the straightness of the screw thread steel is ≤1 mm / m, and cold-rolling threads at the end of the screw thread steel by using a three-axis thread rolling machine;

[0084] e. Coating preparation, mixing nano-ZnO, Sb-ZnO, TiO2 according to the predetermined proportion, adding a predetermined weight of silane coupling agent, then using liquid-solid mass ratio of 3:1 anhydrous ethanol to immerse the dry powder, 60℃, power 200W ultrasonic treatment for 1h, then sequentially carry out suction filtration, 80℃ drying, crushing through 400 mesh screen to obtain nano-powder mixture; the nano-powder mixture, flaky mica powder, sucrose ester dispersing agent, water-based epoxy resin, polyether modified siloxane, mineral oil defoaming agent are added into the reaction kettle according to the predetermined proportion to carry out melting, ultrasonic stirring and mechanical stirring, and an anti-microbial corrosion coating with a final viscosity of 90~110cP and a particle size distribution of D50=85±10nm is obtained;

[0085] f. Rod body surface spray coating, the rod body is sequentially subjected to sand blasting rust removal and oil removal, 60℃ preheating for 1h, and the anti-microbial corrosion coating is uniformly sprayed on the surface of the rod body by using electrostatic spraying process.

[0086] The manufacturing method of the corrosion-resistant anchor rod provided by the embodiment of the present application adds alloy elements effective in inhibiting microorganisms in the rod body manufacturing process, adjusts the composition of the anchor rod, and coats an anti-microbial corrosion coating containing a nano-ZnO bacteriostatic material on the surface of the rod body and adjusts the components of the coating, so that the coating has good coating performance and can inhibit the corrosion of various microorganisms in the well on the anchor rod. The present application improves the corrosion resistance of the anchor rod while ensuring the mechanical properties of the anchor rod, can not only inhibit the adhesion of microorganisms, but also can block the electrochemical corrosion chain, ensure the service safety of the anchor rod in the process of coal mine roadway support, and solve the serious problem of corrosion of the existing anchor rod by microorganisms in the well.

[0087] In some embodiments, in step a, the molten iron, scrap steel, alloy, and limestone are smelted, and the proportions of the components are adjusted to ensure that the composition and mass percentage in the molten steel are: Fe 94.36%~95.27%, C 0.111~0.134%, Cu 0.2~0.4%, Si 0.30~0.34%, Mn 0.74~0.88%, Ni 1.37~1.55%, Cr 1.84~2.04%, Mo 0.06~0.12%, V 0.07~0.09%, W 0.005~0.015%, Co 0.03~0.05%, P ≤0.026%, S ≤0.003%, to obtain refined molten steel.

[0088] In some embodiments, in step e, the nanometer powder mixture, flaky mica powder, sucrose ester dispersant, water-based epoxy resin, polyether modified siloxane, mineral oil antifoaming agent are added into the reaction kettle in a predetermined ratio for melting, ultrasonic stirring and mechanical stirring, and the components and mass percentage in the coating are adjusted to be: water-based epoxy resin 58%~77%, nanometer ZnO 3%~5%, Sb doped nanometer ZnO 2%~3%, nanometer TiO2 2%~3%, flaky mica powder 4%~6%, silane coupling agent 10%~25%, polyether modified siloxane 0.3%~0.5%, mineral oil antifoaming agent 0.2%~0.3%, sucrose ester dispersant 0.5%~1%.

[0089] In some embodiments, in step f, the rod body is sequentially subjected to sand blasting rust removal and oil removal, and the specific operation is that the rod body is subjected to rust removal by adopting a sand blasting rust removal process, and the surface roughness Ra of the rod body is ensured to be 40~60μm, so as to enhance the adhesion of the coating, and the oil removal is performed by spraying the rod body with an alkaline cleaning agent with pH=9.5 at 60℃ for 3min, then rinsing the rod body with deionized water and blowing the rod body dry with compressed air, so that the surface of the rod body is kept dry, clean and pollution-free.

[0090] The specific embodiments of the manufacturing method of the corrosion-resistant anchor rod are as follows: Example 5

[0091] A manufacturing method of a corrosion-resistant anchor rod, comprising the following steps:

[0092] (1) Steel billet smelting, smelting molten iron, scrap steel, alloy, limestone according to the preset mass percentage of each component in example 1, keeping the end point carbon content at 0.124%, limestone for slagging desulfurization and dephosphorization, keeping the phosphorus content in the molten steel at 0.024% and the sulfur content at 0.002%, obtaining refined molten steel at 1680℃;

[0093] (2) Continuous casting, pouring the refined molten steel into a 150×150mm mold for continuous casting, cooling the steel billet at a cooling water amount of 1.2L / kg steel and a drawing speed of 2.2m / min, and detecting the billet defects after cooling, and eliminating the defective billets;

[0094] (3) Hot rolling, placing the detected steel billet into a heating furnace for pretreatment, heating temperature 1250℃, soaking time 130min, oxygen content in the furnace 0.5%; the pretreated continuous casting billet is sequentially subjected to rough rolling into a rod with a diameter of 60mm, water cooling and finish rolling into a left-handed non-longitudinal rib screw thread steel with a diameter of 25mm;

[0095] (4). Rod body finishing, using hydraulic cold shears to cut the finished threaded steel according to the specified length, ensuring that the cut is smooth and the inclination is 0.51°, using multi-roll reverse bending straightening process (9 rolls) to straighten the threaded steel, ensuring that the threaded steel is straight and the straightness is 0.81 mm / m, using a three-axis thread rolling machine to cold roll the threads at the end of the threaded steel;

[0096] (5). Coating preparation, mixing nano-ZnO, Sb-ZnO and TiO2 according to the proportions in Example 1 (8% of the total weight), adding 21.1% silane coupling agent, then immersing the dry powder in anhydrous ethanol with a liquid-solid mass ratio of 3:1, ultrasonic treatment at 60°C and power 200W for 1h, then sequentially performing suction filtration, drying at 80°C, and crushing through a 400 mesh sieve to obtain a nano-powder mixture; adding the nano-powder mixture, flaky mica powder, sucrose ester dispersant, water-based epoxy resin, polyether modified siloxane, and mineral oil defoaming agent into a reaction kettle according to the predetermined proportions, and performing melting, ultrasonic stirring and mechanical stirring to obtain an antimicrobial corrosion coating with a final viscosity of 100 cP and a particle size distribution of D50=87 nm;

[0097] (6). Rod body surface spraying coating, sequentially sandblasting, rust removal and oil removal, preheating at 60°C for 1h, using electrostatic spraying process to uniformly spray the antimicrobial corrosion coating on the surface of the rod body, and the coating sequentially undergoes wet film spraying, 25°C surface drying for 2h, staged temperature rising (20, 40, 60°C for 20min), 80°C constant temperature curing for 30min, and slow cooling to room temperature, ensuring that the coating surface is continuous, uniform, smooth, free of bubbles, pinholes, cracks, impurities, sagging and other defects, and the dry film thickness is 81μm.

[0098] Example 6

[0099] A method for manufacturing a corrosion-resistant anchor rod, comprising the following steps:

[0100] (1). Steel billet smelting, smelting molten iron, scrap steel, alloy, and limestone according to the predetermined mass percentage of each component in Example 2, maintaining the end-point carbon content at 0.114%, and limestone for slagging desulfurization and dephosphorization, so that the phosphorus content in the molten steel is maintained at 0.014% and the sulfur content is maintained at 0.001%, obtaining refined molten steel at 1650°C;

[0101] (2). Continuous casting, pouring the refined molten steel into a 150x150mm mold for continuous casting, cooling the billet at a cooling water amount of 1L / kg of steel and a pulling speed of 1.8m / min, and detecting the billet defects after cooling, and eliminating the defective billets;

[0102] (3) Hot rolling forming, the detected steel billet is put into a heating furnace for pretreatment, the heating temperature is 1150℃, the soaking time is 125min, the oxygen content in the furnace is 0.3%; the pretreated continuous casting billet is subjected to rough rolling into a rod with a diameter of 60mm, water cooling and fine rolling into a left-handed non-longitudinal rib screw thread steel with a diameter of 18mm;

[0103] (4) Rod body finishing, the screw thread steel after fine rolling is cut according to the specified length by using a hydraulic cold shearing machine, the cut surface is ensured to be smooth, the inclination is 0.8°, the screw thread steel is straightened and strengthened by using a multi-roller reverse bending straightening process (9 rollers), the straightness of the screw thread steel is ensured to be straight, the straightness is 0.52mm / m, the end of the screw thread steel is subjected to cold rolling thread by using a three-shaft thread rolling machine;

[0104] (5) Coating preparation, the nano ZnO, Sb-ZnO and TiO2 are mixed according to the proportion in embodiment 2 (accounting for 10% of the total weight), 12% of silane coupling agent is added, then the dry powder is immersed by using anhydrous ethanol with a liquid-solid mass ratio of 3:1, ultrasonic treatment is carried out at 60℃ and a power of 200W for 1h, then the nano powder mixture is obtained by carrying out suction filtration, drying at 80℃ and crushing through a 400 mesh screen in sequence; the nano powder mixture, flaky mica powder, sucrose ester dispersant, water-based epoxy resin, polyether modified siloxane and mineral oil defoaming agent are added into a reaction kettle according to a predetermined proportion to carry out melting, ultrasonic stirring and mechanical stirring, and finally an anti-microbial corrosion coating with a viscosity of 110cP and a particle size distribution of D50=82nm is obtained;

[0105] (6) Rod body surface spraying coating, the rod body is subjected to sand blasting rust removal and oil removal, preheating at 60℃ for 1h in sequence, the anti-microbial corrosion coating is uniformly sprayed on the surface of the rod body by using an electrostatic spraying process, the coating is subjected to wet film spraying, surface drying at 25℃ for 2h, stage heating (20, 40, 60℃ for 20min), 80℃ constant temperature curing for 30min and slow cooling to room temperature in sequence, and the coating surface is ensured to be continuous, uniform, smooth, free of defects such as bubbles, pinholes, cracks, impurities and sagging, and the dry film thickness is 85μm.

[0106] Corrosion resistance test of the corrosion-resistant anchor rod

[0107] Comparative example

[0108] The ordinary anchor rod for mining (Fe 98%, C 0.22%, Si:0.25%, Mn 1.2%, P 0.045%, S 0.05%) is used as a control anchor rod.

[0109] Figure 1 The physical map of the coated anchor rod of embodiment 5, wherein the white wrapping material on the surface of the anchor rod is the anti-microbial corrosion coating containing the nano ZnO bacteriostatic material, and the white coating wraps the anchor rod body with anti-microbial corrosion.

[0110]

[0111] As shown in Table 1, the corrosion-resistant anchor rod provided by the embodiment of the present application has good mechanical properties.

[0112] (1) Test scheme

[0113] According to the real service environment of the anchor rod in a certain underground coal mine seriously corroded by microorganisms, the concentrations of various ions and various microorganisms in the mine water environment in which the anchor rod serves are measured, and a corrosion solution with the same concentration is configured. The coated anchor rod material of Example 5 and the ordinary mine anchor rod material of the comparative example are respectively immersed in the prepared corrosion solution for long-term indoor immersion corrosion test, and the corrosion conditions of the two kinds of anchor rod materials are observed and compared.

[0114] (2) Corrosion result analysis

[0115] After being immersed in the corrosion solution for 100 days, the two kinds of anchor rod materials are taken out in turn for cleaning, rust removal and scanning electron microscope observation. Figure 2 The scanning electron microscope pictures are shown in FIGS. 5 and 6, wherein FIG. 5(a) is the appearance of the coated anchor rod material of Example 5 after being corroded for 100 days, and FIG. 5(b) is the appearance of the ordinary mine anchor rod material of the comparative example after being corroded for 100 days.

[0116] The corrosion conditions of the anchor rod materials of Example 5 and the comparative example are analyzed, and it can be seen from FIGS. 5 and 6 that Figure 2 After 100 days of corrosion, the number of corrosion pits on the surface of the coated anchor rod material of Example 5 is small, the distribution is sparse, the surface is relatively flat, the local corrosion is slight, the corrosion pits are few and independent, the edge is clear, and the performance is mild corrosion state; the number of corrosion pits on the surface of the ordinary mine anchor rod material of the comparative example is large, the distribution is dense, the surface is rough and uneven as a whole, the corrosion pits are connected into a piece, the boundary is blurred, and the performance is severe corrosion state.

[0117] Comprehensive comparison of the mechanical properties and corrosion results of the coated anchor rod and the ordinary mine anchor rod shows that the mechanical properties of the coated anchor rod are good, and the corrosion degree is obviously lighter than that of the ordinary mine anchor rod. The anti-microbial corrosion performance of the coated anchor rod is excellent.

[0118] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical range disclosed by the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A corrosion resistant anchor rod, characterized in that, The utility model relates to a kind of left-handed screw thread steel bars with anti-microbial corrosion coating, including: Rod body and the anti-microbial corrosion coating coated on the surface of the rod body; Wherein, the composition and mass percentage of the rod body are as follows: Fe 94.36%~95.27%, C 0.111~0.134%, Cu 0.2~0.4%, Si 0.3~0.34%, Mn 0.74~0.88%, Ni 1.37~1.55%, Cr 1.84~2.04%, Mo 0.06~0.12%, V 0.07~0.09%, W 0.005~0.015%, Co 0.03~0.05%, P ≤0.026%, S ≤0.003%; The composition and mass percentage of the anti-microbial corrosion coating are as follows: water-based epoxy resin 57%~78%, nano-ZnO 3%~5%, Sb-doped nano-ZnO 2%~3%, nano-TiO2 2%~3%, flaky mica powder 4%~6%, silane coupling agent 10%~25%, polyether-modified siloxane 0.3%~0.5%, mineral oil antifoam agent 0.2%~0.3%, sucrose ester dispersant 0.5%~1%; wherein, in the Sb-doped nano-ZnO, Zn / Sb=10:

1.

2. The corrosion resistant anchor rod of claim 1, wherein, The particle size of the nano-ZnO and nano-TiO2 is 20~40 nm respectively, and the diameter-thickness ratio of the flaky mica powder is >50.

3. A method of manufacturing a corrosion resistant anchor rod as claimed in any one of claims 1-2, characterized in that, The utility model relates to a kind of left-handed screw thread steel bars with anti-microbial corrosion coating, including the following steps: a. Steel billet smelting, molten iron, scrap steel, alloy, limestone prepared according to the preset mass percentage of each component are smelted, the end-point carbon content is kept at 0.111~0.134%, limestone is used for slagging desulfurization and dephosphorization, so that the phosphorus content in molten steel is kept below 0.026%, the sulfur content is kept below 0.003%, and refined molten steel at 1650~1680 ℃ is obtained; b. Continuous casting, pour the refined molten steel into a mold for continuous casting, cool the steel billet at a cooling water amount of 0.8~1.2 L / kg steel and a drawing speed of 1.8~2.2 m / min, detect the billet defects after cooling, and eliminate the defective billets; c. Hot rolling, place the detected steel billet into a heating furnace for pretreatment, the heating temperature is 1150~1250 ℃, the soaking time is ≥120 min, and the oxygen content in the furnace is ≤0.5%; the pretreated continuous casting billet is successively coarsely rolled into a bar with a diameter of 60 mm, water-cooled, and finely rolled into left-handed screw thread steel with a diameter of 18~25 mm without longitudinal reinforcement; d. Rod body finishing, cut the screw thread steel after finishing according to the specified length using a hydraulic cold shearing machine, ensure that the cutting inclination is ≤1°, straighten the screw thread steel using multi-roll reverse bending straightening process to strengthen, ensure that the straightness of the screw thread steel is ≤1 mm / m, and cold roll the threads at the end of the screw thread steel using a three-axis thread rolling machine. e. Coating preparation, the nano ZnO, Sb-ZnO, TiO2 is mixed according to the predetermined proportion, add the predetermined proportion of silane coupling agent, then use liquid solid mass ratio is 3:1 anhydrous ethanol to immerse dry powder, 60℃, power 200W ultrasonic treatment 1h, then carry on filtration, 80℃ drying, crushing through 400 mesh screen in turn to obtain nano powder mixture; The nano powder mixture, flaky mica powder, sucrose ester dispersing agent, water-based epoxy resin, polyether modified siloxane, mineral oil antifoaming agent is added into the reaction kettle according to the predetermined proportion to melt, ultrasonic stirring and mechanical stirring, the final viscosity is 90~110cP, the particle size distribution is D50=85±10nm of antimicrobial corrosion coating is obtained; f. The rod body surface is sprayed with a coating, the rod body is sequentially subjected to sand blasting, rust removal and oil removal, and is preheated at 60℃ for 1h. The antimicrobial corrosion coating is uniformly sprayed on the surface of the rod body using an electrostatic spraying process.

4. The method of manufacturing a corrosion-resistant anchor rod according to claim 3, characterized by, In step a, molten iron, scrap steel, alloy, limestone are smelted, the proportion of each component is adjusted to ensure that the composition and mass percentage in the molten steel are: Fe 94.36%~95.27%, C 0.111~0.134%, Cu 0.2~0.4%, Si 0.30~0.34%, Mn 0.74~0.88%, Ni 1.37~1.55%, Cr 1.84~2.04%, Mo 0.06~0.12%, V 0.07~0.09%, W 0.005~0.015%, Co 0.03~0.05%, P≤0.026%, S≤0.003%, to obtain refined molten steel.

5. The method of manufacturing a corrosion resistant anchor rod according to claim 3, wherein In step e, the nano powder mixture, flaky mica powder, sucrose ester dispersing agent, water-based epoxy resin, polyether modified siloxane, mineral oil antifoaming agent are added into the reaction kettle according to the predetermined proportion to melt, ultrasonic stirring and mechanical stirring, the proportion of each component is adjusted to ensure that the composition and mass percentage in the coating are: water-based epoxy resin 58%~77%, nano ZnO 3%~5%, Sb-doped nano ZnO 2%~3%, nano TiO2 2%~3%, flaky mica powder 4%~6%, silane coupling agent 10%~25%, polyether modified siloxane 0.3%~0.5%, mineral oil antifoaming agent 0.2%~0.3%, sucrose ester dispersing agent 0.5%~1%.

6. The method of manufacturing a corrosion resistant anchor rod according to claim 3, wherein In step f, the rod body is sequentially subjected to sand blasting, rust removal and oil removal, and the specific operation is to remove rust on the rod body using a sand blasting rust removal process, and to ensure that the surface roughness Ra of the rod body is 40~60μm to enhance the adhesion of the coating. After the rod body is sprayed with an alkaline cleaning agent at 60℃ for 3min, the rod body is rinsed with deionized water and dried with compressed air, and the surface of the rod body is kept dry, clean and pollution-free.

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