A corrosion-resistant hot-dip galvanized anchor bolt and its preparation method

Abstract

The present invention relates to the technical field of anchor bolts and provides a corrosion-resistant hot-dip galvanized anchor bolt and its preparation method. The hot-dip galvanized anchor bolt is obtained by hot-dip galvanizing the anchor bolt body. Prior to hot-dip galvanizing, the anchor bolt body also undergoes a flux plating treatment. The anchor bolt body is composed of the following components in percentage by weight: C, Mn, Mo, Co, Mg, Cu, W, Al, Nb, Y, S, and P, with the remainder being iron and unavoidable impurities. This technical solution overcomes the problems of poor corrosion resistance and mechanical strength of hot-dip galvanized anchor bolts in related technologies.

Description

Technical Field

[0001] The present invention relates to the technical field of anchor bolts, and in particular to a corrosion-resistant hot-dip galvanized anchor bolt and a preparation method thereof. Background Art

[0002] An anchor bolt is a component used to fasten mechanical equipment to the ground. It is typically composed of a screw, nut, and washer. One end of the bolt is usually buried in the ground, while the other end is connected to the mechanical equipment to be fixed through a nut or other equipment connector, thereby stabilizing the equipment and preventing it from shifting or shaking.

[0003] Hot-dip galvanized anchor bolts are treated with a special hot-dip galvanizing process. During this process, the bolts undergo pre-treatment steps such as pickling. They are then immersed in a high-temperature zinc bath, where the zinc layer firmly adheres to the bolt surface, forming a protective film. This zinc coating enhances the bolts' corrosion resistance and is particularly suitable for structures and facilities exposed to atmospheric conditions and susceptible to rain, dew, and other corrosion, such as outdoor structures, coastal engineering buildings, and agricultural facilities.

[0004] However, the protective capabilities of hot-dip galvanizing on anchor bolts are still limited. In some highly corrosive environments, the hot-dip galvanizing layer may not be able to maintain the integrity of the anchor bolts for a long time, and may even have a negative impact on their mechanical strength.

[0005] Therefore, the development of a hot-dip galvanized anchor bolt with excellent corrosion resistance and mechanical strength is of great significance for extending the service life of the bolt and ensuring its stable performance in various environments. Summary of the Invention

[0006] The invention provides a corrosion-resistant hot-dip galvanized anchor bolt and a preparation method thereof, which solves the problems of poor corrosion resistance and poor mechanical strength of the hot-dip galvanized anchor bolt in the related art.

[0007] The technical solutions of the present invention are as follows:

[0008] The present invention provides a corrosion-resistant hot-dip galvanized anchor bolt, which is obtained by hot-dip galvanizing the anchor bolt body. Before the hot-dip galvanizing, the anchor bolt body needs to undergo a plating treatment. The anchor bolt body is composed of the following components in the following weight percentages:

[0009] C 0.28%~0.35%, Mn 0.41%~0.65%, Mo 0.102%~0.244%, Co 0.14%~0.16%, Mg 0.18%~0.28%, Cu 0.2%~0.26%, W 0.135%~0.26%, Al 0.18%~0.26%, Nb 0.008%~0.056%, Y 0.05%~0.08%, S≤0.016%, P≤0.0035%, and the rest are iron and unavoidable impurities.

[0010] As a further technical solution, the ratio of the weight of the Mg to the sum of the weights of the Mo and the Nb is 1≤Mg / (Mo+Nb)≤1.5.

[0011] When the ratio of the weight of Mg to the sum of the weights of Mo and Nb is 1≤Mg / (Mo+Nb)≤1.5, the mechanical properties of the anchor bolt body can be further improved.

[0012] As a further technical solution, the weight ratio of the Mo to the Nb is 9:1.

[0013] As a further technical solution, during the plating assist treatment, the plating assist agent includes the following components in parts by weight:

[0014] 32-42 parts of zinc chloride, 8-10 parts of ammonium chloride, 4-8 parts of sodium fluoride, 0.2-0.6 parts of emulsifier, 1-10 parts of monoethyl fumarate, 3-9 parts of sodium gluconate, and 80 parts of water.

[0015] In the present invention, zinc chloride is a key component of the plating flux, and cooperates with ammonium chloride, sodium fluoride, an emulsifier, monoethyl fumarate and sodium gluconate to provide a good foundation for the hot-dip galvanizing process of the anchor bolts during the plating flux treatment process, thereby effectively improving the quality of the hot-dip galvanized layer. Specifically, when monoethyl fumarate and sodium gluconate are added to the plating flux, the combined use of monoethyl fumarate and sodium gluconate not only improves the stability of the plating flux, but also promotes a more uniform and stable galvanized layer during the hot-dip galvanizing process, thereby improving the corrosion resistance of the hot-dip galvanized anchor bolts.

[0016] As a further technical solution, the weight ratio of the sodium gluconate to the monoethyl fumarate is 1-2:1.

[0017] When the weight ratio of sodium gluconate to monoethyl fumarate is 1-2:1, the corrosion resistance of the hot-dip galvanized anchor bolts can be further improved.

[0018] As a further technical solution, the emulsifier includes one or more of fatty alcohol polyoxyethylene ether, sodium dodecylbenzene sulfonate, and alkylphenol polyoxyethylene ether.

[0019] As a further technical solution, during the hot-dip galvanizing, the zinc solution is composed of the following components in percentage by weight:

[0020] Fe 0.025%~0.035%, Sn 0.15%~0.25%, Mg 0.06%~0.09%, Si 0.2%~0.4%, and the rest is zinc and its inevitable impurities.

[0021] The present invention also provides a method for preparing the corrosion-resistant hot-dip galvanized anchor bolts, comprising the following steps:

[0022] S1. Dispensing and melting components according to the weight percentage of the anchor bolt body to obtain molten steel;

[0023] S2, casting the molten steel and cooling it to obtain an anchor bolt blank;

[0024] S3, threading, heat treatment, and cryogenic treatment the anchor bolt blank to obtain an anchor bolt;

[0025] S4, pickling and washing the anchor bolt body with water, and then placing the anchor bolt body in a fluxing agent for fluxing treatment to obtain a fluxed anchor bolt;

[0026] S5, placing the anchor bolts after the plating assistance in a zinc solution for hot-dip galvanizing treatment, and then finishing, passivating, and cooling to obtain hot-dip galvanized anchor bolts.

[0027] As a further technical solution, in step S3, during the heat treatment, the temperature is raised to 600~800℃, kept warm for 1~2 hours, and then cooled to room temperature; during the deep freezing treatment, the temperature is -60~-80℃ and the time is 1~2 hours.

[0028] As a further technical solution, in step S4, the assist plating treatment lasts for 3 to 6 minutes.

[0029] As a further technical solution, in step S5, the temperature of the zinc solution is 450-540°C, the hot dip galvanizing time is 20-30s, and the galvanizing amount is 40-70g / m 2 .

[0030] The working principle and beneficial effects of the present invention are:

[0031] The present invention utilizes a rationally proportioned combination of specific components to create an anchor bolt body with excellent mechanical properties, making it suitable for applications in construction, industry, and other fields requiring high structural connection stability. By rationally regulating the contents of Mg, Mo, and Nb, the anchor bolt body's strength under load can be significantly enhanced, thus meeting demanding and complex mechanical conditions. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making any creative efforts are within the scope of protection of the present invention.

[0033] In the following embodiments and comparative examples, the Mn content in the manganese-iron alloy is 75wt%; the Mo content in the molybdenum-iron alloy is 60wt%; the Co content in the iron-cobalt alloy is 50wt%; the Mg content in the magnesium ingot is 99.95wt%; the Cu content in the copper-iron alloy is 90wt%; the W content in the tungsten-iron alloy is 75wt%; the Al content in the aluminum ingot is 99.8wt%; the Nb content in the niobium-iron alloy is 70wt%; the Y content in the yttrium-iron alloy is 60wt%; the Fe content in the scrap steel is 97wt%; and the model of the fatty alcohol polyoxyethylene ether is AEO-9.

[0034] Example 1

[0035] A corrosion-resistant hot-dip galvanized anchor bolt is obtained by hot-dip galvanizing the anchor bolt body. Before hot-dip galvanizing, it also needs to undergo a plating treatment. The anchor bolt body is composed of the following components in percentage by weight:

[0036] C 0.28%, Mn 0.41%, Mo 0.102%, Co 0.14%, Mg 0.18%, Cu 0.2%, W 0.135%, Al 0.18%, Nb 0.008%, Y 0.05%, S 0.003%, P 0.001%, the rest is iron and unavoidable impurities;

[0037] During the plating flux treatment, the plating flux includes the following components in parts by weight:

[0038] 32 parts of zinc chloride, 8 parts of ammonium chloride, 4 parts of sodium fluoride, 0.2 parts of fatty alcohol polyoxyethylene ether, 1 part of monoethyl fumarate, 3 parts of sodium gluconate, 80 parts of water;

[0039] During hot-dip galvanizing, the zinc solution is composed of the following components in weight percentage:

[0040] Fe 0.025%, Sn 0.15%, Mg 0.06%, Si 0.2%, the remainder is zinc and its inevitable impurities;

[0041] The preparation method of hot-dip galvanized anchor bolts comprises the following steps:

[0042] S1. Mixing ferromanganese alloy, ferromolybdenum alloy, iron-cobalt alloy, magnesium ingot, copper-ferroalloy, ferrotungsten alloy, aluminum ingot, ferroniobium alloy, ferroydtrium alloy and scrap steel in proportion to the weight of the anchor bolt body, and smelting to obtain molten steel;

[0043] S2, casting and cooling the molten steel to obtain an anchor bolt blank;

[0044] S3, after threading the anchor bolt blank, heating it to 600°C and keeping it at that temperature for 2 hours, cooling it to room temperature, completing the heat treatment, and then performing a deep cryogenic treatment at -60°C for 2 hours to obtain the anchor bolt;

[0045] S4. After pickling and water washing, the anchor bolt body is placed in a fluxing agent for fluxing treatment. After the fluxing treatment for 6 minutes, the fluxed anchor bolt is obtained;

[0046] S5. Place the anchor bolts after galvanizing in 450℃ zinc bath for hot dip galvanizing. After 30s, the galvanizing amount is 70g / m 2 After finishing, passivation and cooling, hot-dip galvanized anchor bolts are obtained.

[0047] Example 2

[0048] A corrosion-resistant hot-dip galvanized anchor bolt is obtained by hot-dip galvanizing the anchor bolt body. Before hot-dip galvanizing, it also needs to undergo a plating treatment. The anchor bolt body is composed of the following components in percentage by weight:

[0049] C 0.32%, Mn 0.5%, Mo 0.189%, Co 0.15%, Mg 0.19%, Cu 0.23%, W 0.2%, Al 0.22%, Nb 0.021%, Y 0.065%, S 0.01%, P 0.002%, the rest is iron and unavoidable impurities;

[0050] During the plating flux treatment, the plating flux includes the following components in parts by weight:

[0051] 37 parts of zinc chloride, 9 parts of ammonium chloride, 6 parts of sodium fluoride, 0.4 parts of fatty alcohol polyoxyethylene ether, 8 parts of monoethyl fumarate, 4 parts of sodium gluconate, 80 parts of water;

[0052] During hot-dip galvanizing, the zinc solution is composed of the following components in weight percentage:

[0053] Fe 0.03%, Sn 0.2%, Mg 0.08%, Si 0.3%, the remainder is zinc and its inevitable impurities;

[0054] The preparation method of hot-dip galvanized anchor bolts comprises the following steps:

[0055] S1. Mixing ferromanganese alloy, ferromolybdenum alloy, iron-cobalt alloy, magnesium ingot, copper-ferroalloy, ferrotungsten alloy, aluminum ingot, ferroniobium alloy, ferroydtrium alloy and scrap steel in proportion to the weight of the anchor bolt body, and smelting to obtain molten steel;

[0056] S2, casting and cooling the molten steel to obtain an anchor bolt blank;

[0057] S3, after threading the anchor bolt blank, heating it to 700°C and keeping it at that temperature for 1.5 hours, cooling it to room temperature, completing the heat treatment, and then performing a deep cryogenic treatment at -70°C for 1.5 hours to obtain the anchor bolt;

[0058] S4. After pickling and water washing, the anchor bolt body is placed in a fluxing agent for fluxing treatment. After fluxing treatment for 4.5 minutes, a fluxed anchor bolt is obtained;

[0059] S5. Place the anchor bolts after galvanizing in 490℃ zinc bath for hot dip galvanizing. After 25s, the galvanizing amount is 55g / m 2 After finishing, passivation and cooling, hot-dip galvanized anchor bolts are obtained.

[0060] Example 3

[0061] A corrosion-resistant hot-dip galvanized anchor bolt is obtained by hot-dip galvanizing the anchor bolt body. Before hot-dip galvanizing, it also needs to undergo a plating treatment. The anchor bolt body is composed of the following components in percentage by weight:

[0062] C 0.35%, Mn 0.65%, Mo 0.244%, Co 0.16%, Mg 0.28%, Cu 0.26%, W 0.26%, Al 0.26%, Nb 0.056%, Y 0.08%, S 0.016%, P 0.0035%, the rest is iron and unavoidable impurities;

[0063] During the plating flux treatment, the plating flux includes the following components in parts by weight:

[0064] 42 parts of zinc chloride, 10 parts of ammonium chloride, 8 parts of sodium fluoride, 0.6 parts of fatty alcohol polyoxyethylene ether, 10 parts of monoethyl fumarate, 9 parts of sodium gluconate, 80 parts of water;

[0065] During hot-dip galvanizing, the zinc solution is composed of the following components in weight percentage:

[0066] Fe 0.035%, Sn 0.25%, Mg 0.09%, Si 0.4%, the remainder is zinc and its inevitable impurities;

[0067] The preparation method of hot-dip galvanized anchor bolts comprises the following steps:

[0068] S1. Mixing ferromanganese alloy, ferromolybdenum alloy, iron-cobalt alloy, magnesium ingot, copper-ferroalloy, ferrotungsten alloy, aluminum ingot, ferroniobium alloy, ferroydtrium alloy and scrap steel in proportion to the weight of the anchor bolt body, and smelting to obtain molten steel;

[0069] S2, casting and cooling the molten steel to obtain an anchor bolt blank;

[0070] S3, after threading the anchor bolt blank, heating it to 800°C and keeping it at that temperature for 1 hour, cooling it to room temperature, completing the heat treatment, and then performing a deep cryogenic treatment at -80°C for 1 hour to obtain the anchor bolt;

[0071] S4, after pickling and washing the anchor bolt body with water, placing it in a fluxing agent for fluxing treatment, and performing fluxing treatment for 3 minutes to obtain a fluxed anchor bolt;

[0072] S5. Place the anchor bolts after galvanizing in 540℃ zinc bath for hot dip galvanizing. After 20s, the galvanizing amount is 40g / m 2 After finishing, passivation and cooling, hot-dip galvanized anchor bolts are obtained.

[0073] Example 4

[0074] The only difference between this embodiment and embodiment 2 is that, in this embodiment, the weight percentage of Mg added is 0.28%, the weight percentage of Mo added is 0.108%, and the weight percentage of Nb added is 0.012%.

[0075] Example 5

[0076] The only difference between this embodiment and embodiment 2 is that, in this embodiment, the weight percentage of Mg added is 0.2%, the weight percentage of Mo added is 0.15%, and the weight percentage of Nb added is 0.05%.

[0077] Example 6

[0078] The only difference between this embodiment and embodiment 2 is that, in this embodiment, the weight percentage of Mg added is 0.24%, the weight percentage of Mo added is 0.12%, and the weight percentage of Nb added is 0.04%.

[0079] Example 7

[0080] The only difference between this embodiment and embodiment 6 is that, in this embodiment, no sodium gluconate is added to the plating flux, and 12 parts of monoethyl fumarate are added.

[0081] Example 8

[0082] The only difference between this embodiment and embodiment 6 is that, in this embodiment, no monoethyl fumarate is added to the plating flux, and 12 parts of sodium gluconate are added.

[0083] Example 9

[0084] The only difference between this embodiment and embodiment 6 is that, in this embodiment, monoethyl fumarate and sodium gluconate are not added to the plating flux.

[0085] Example 10

[0086] The only difference between this embodiment and embodiment 6 is that in this embodiment, 8.5 parts of sodium gluconate and 3.5 parts of monoethyl fumarate are added to the plating flux.

[0087] Example 11

[0088] The only difference between this embodiment and embodiment 6 is that, in this embodiment, 6 parts of sodium gluconate and 6 parts of monoethyl fumarate are added to the plating flux.

[0089] Example 12

[0090] The only difference between this embodiment and embodiment 6 is that, in this embodiment, 8 parts of sodium gluconate and 4 parts of monoethyl fumarate are added to the plating flux.

[0091] Comparative Example 1

[0092] The only difference between this comparative example and Example 1 is that in this comparative example, no Nb is added, the weight percentage of Mg added is 0.18%, and the weight percentage of Mo added is 0.11%.

[0093] Comparative Example 2

[0094] The only difference between this comparative example and Example 1 is that in this comparative example, no Mo is added, the weight percentage of Mg added is 0.18%, and the weight percentage of Nb added is 0.11%.

[0095] Comparative Example 3

[0096] The only difference between this comparative example and Example 1 is that in this comparative example, Nb and Mo are not added, and the weight percentage of Mg added is 0.29%.

[0097] Comparative Example 4

[0098] The only difference between this comparative example and Example 1 is that in this comparative example, no Mg is added, the weight percentage of Mo added is 0.269%, and the weight percentage of Nb added is 0.021%.

[0099] Comparative Example 5

[0100] The only difference between this comparative example and Example 1 is that in this comparative example, Nb, Mo and Mg are not added.

[0101] Test Example 1 Mechanical properties test

[0102] Based on the test method in GB / T 228.1-2021 "Tensile test of metallic materials Part 1: Room temperature test method", the tensile strength of the anchor bolt bodies prepared in Examples 1 to 6 and Comparative Examples 1 to 5 was tested, wherein the test rate was 0.008s -1 , the test results are shown in Table 1 below:

[0103] Table 1 Test results of tensile strength of anchor bolt bodies of Examples 1 to 6 and Comparative Examples 1 to 5

[0104]

[0105] As can be seen from Table 1, compared with Comparative Examples 1 to 5, the tensile strength of Example 1 is significantly improved, indicating that when Mg, Mo and Nb are introduced into the anchor bolt body, the mechanical properties of the anchor bolt body can be significantly improved by the combined use of Mg, Mo and Nb.

[0106] Compared with Examples 2 and 4, the tensile strength of Examples 5-6 is improved, indicating that when the ratio of the weight of Mg to the sum of the weights of Mo and Nb is 1≤Mg / (Mo+Nb)≤1.5, the mechanical properties of the anchor bolt body can be further improved.

[0107] Test Example 2 Corrosion Resistance Test

[0108] The hot-dip galvanized anchor bolts prepared in Examples 6 to 12 were immersed in an 18% hydrochloric acid aqueous solution for 60 minutes. The corrosion loss test was performed based on the mass before and after immersion. The corrosion loss (%) = (mass of the hot-dip galvanized anchor bolt before corrosion - mass of the hot-dip galvanized anchor bolt after corrosion) / mass of the hot-dip galvanized anchor bolt before corrosion × 100%. The test results are as follows:

[0109] Table 2 Corrosion reduction test results of hot-dip galvanized anchor bolts in Examples 6 to 12

[0110]

[0111] As can be seen from Table 2, compared with Examples 7 to 9, the corrosion loss of the hot-dip galvanized anchor bolts in Examples 6 and 10 to 12 is significantly reduced, indicating that when monoethyl fumarate and sodium gluconate are present in the plating flux, monoethyl fumarate and sodium gluconate have a synergistic effect and can improve the corrosion resistance of the hot-dip galvanized anchor bolts.

[0112] Compared with Examples 6 and 10, the corrosion loss of the hot-dip galvanized anchor bolts in Examples 11-12 is reduced, indicating that when the weight ratio of sodium gluconate to monoethyl fumarate is 1-2:1, the corrosion resistance of the hot-dip galvanized anchor bolts can be further improved.

[0113] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A corrosion-resistant hot-dip galvanized anchor bolt, which is obtained by hot-dip galvanizing the anchor bolt body. Before the hot-dip galvanizing, it needs to undergo a plating treatment, characterized in that: The anchor bolt body is composed of the following components in percentage by weight: C 0.28%~0.35%, Mn 0.41%~0.65%, Mo 0.102%~0.244%, Co 0.14%~0.16%, Mg 0.18%~0.28%, Cu 0.2%~0.26%, W 0.135%~0.26%, Al 0.18%~0.26%, Nb 0.008%~0.056%, Y 0.05%~0.08%, S≤0.016%, P≤0.0035%, the rest are iron and unavoidable impurities; During the plating assist treatment, the plating assist agent includes the following components in parts by weight: 32-42 parts of zinc chloride, 8-10 parts of ammonium chloride, 4-8 parts of sodium fluoride, 0.2-0.6 parts of emulsifier, 1-10 parts of monoethyl fumarate, 3-9 parts of sodium gluconate, and 80 parts of water.

2. The corrosion-resistant hot-dip galvanized anchor bolt according to claim 1, characterized in that: The ratio of the weight of the Mg to the sum of the weights of the Mo and the Nb is 1≤Mg / (Mo+Nb)≤1.

5.

3. The corrosion-resistant hot-dip galvanized anchor bolt according to claim 1, characterized in that: The weight ratio of the Mo to the Nb is 9:

1.

4. The corrosion-resistant hot-dip galvanized anchor bolt according to claim 1, characterized in that: The weight ratio of the sodium gluconate to the monoethyl fumarate is 1-2:

1.

5. The corrosion-resistant hot-dip galvanized anchor bolt according to claim 1, characterized in that: The emulsifier includes one or more of fatty alcohol polyoxyethylene ether, sodium dodecylbenzene sulfonate, and alkylphenol polyoxyethylene ether.

6. The corrosion-resistant hot-dip galvanized anchor bolt according to claim 1, characterized in that: During hot-dip galvanizing, the zinc solution is composed of the following components in percentage by weight: Fe 0.025%~0.035%, Sn 0.15%~0.25%, Mg 0.06%~0.09%, Si 0.2%~0.4%, and the rest is zinc and its inevitable impurities.

7. The method for preparing a corrosion-resistant hot-dip galvanized anchor bolt according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Dispensing and melting components according to the weight percentage of the anchor bolt body to obtain molten steel; S2, casting the molten steel and cooling it to obtain an anchor bolt blank; S3, threading, heat treatment, and cryogenic treatment the anchor bolt blank to obtain an anchor bolt; S4, pickling and washing the anchor bolt body with water, and then placing the anchor bolt body in a fluxing agent for fluxing treatment to obtain a fluxed anchor bolt; S5, placing the anchor bolts after the plating assistance in a zinc solution for hot-dip galvanizing treatment, and then finishing, passivating, and cooling to obtain hot-dip galvanized anchor bolts.

8. The method for preparing a corrosion-resistant hot-dip galvanized anchor bolt according to claim 7, characterized in that: In step S3, during the heat treatment, the temperature is raised to 600-800°C, kept at this temperature for 1-2 hours, and then cooled to room temperature; during the cryogenic treatment, the temperature is -60--80°C and the time is 1-2 hours.

9. The method for preparing a corrosion-resistant hot-dip galvanized anchor bolt according to claim 7, characterized in that: In step S4, the assist plating process is performed for 3 to 6 minutes.

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