A high-strength anchor bolt and its preparation method

Abstract

This invention relates to the field of bolt technology and proposes a high-strength anchor bolt and its preparation method. The anchor bolt comprises a matrix and a reinforcing phase. The matrix is ​​composed of the following components by weight percentage: C 0.2%~0.38%, Mn 0.24%~0.35%, V 0.12%~0.18%, W 0.05%~0.15%, Sn 0.14%~0.28%, Cu 0.018%~0.15%, Se 0.018%~0.15%, P≤0.055%, S≤0.045%, with the remainder being iron and unavoidable impurities. The reinforcing phase is boron nitride. The weight ratio of the matrix to the reinforcing phase is 100:2~5. This technical solution solves the problem of poor mechanical properties in anchor bolts in related technologies.

Description

Technical Field

[0001] This invention relates to the field of bolt technology, specifically to a high-strength anchor bolt and its manufacturing method. Background Technology

[0002] Anchor bolts are fundamental fasteners used to secure machinery or structures to the ground. They play a crucial role in fixing building accessories and ensuring the overall stability of the building structure. For example, in high-rise buildings, elevators are fixed to the structure using anchor bolts. If the anchor bolts malfunction, the elevator may break down, affecting the building's normal operation. Furthermore, for buildings with special requirements, such as earthquake-resistant structures, anchor bolts strengthen the connection between building equipment and the main structure, improving the building's seismic performance in natural disasters like earthquakes and ensuring the safety of people and property within the building. However, traditional anchor bolts have limited mechanical properties, and anchor bolts subjected to various loads over long periods are prone to breakage, reducing their service life and tightening effectiveness. Therefore, improving the mechanical properties of anchor bolts is of great significance for extending their service life. Summary of the Invention

[0003] This invention proposes a high-strength anchor bolt and its preparation method, which solves the problem of poor mechanical properties of anchor bolts in related technologies.

[0004] The technical solution of the present invention is as follows:

[0005] This invention proposes a high-strength anchor bolt, comprising a matrix and a reinforcing phase. The matrix is ​​composed of the following components by weight percentage: C 0.2%~0.38%, Mn 0.24%~0.35%, V 0.12%~0.18%, W 0.05%~0.15%, Sn 0.14%~0.28%, Cu 0.018%~0.15%, Se 0.018%~0.15%, P≤0.055%, S≤0.045%, with the remainder being iron and its unavoidable impurities.

[0006] The reinforcing phase is boron nitride;

[0007] The weight ratio of the matrix to the reinforcing phase is 100:2~5.

[0008] As a further technical solution, the weight ratio of Cu and Se to Sn is 1~3:3.

[0009] When the weight ratio of Cu and Se to Sn is 1~3:3, the mechanical properties of anchor bolts can be further improved.

[0010] As a further technical solution, the weight ratio of Cu to Se is 1:1.

[0011] As a further technical solution, the median particle size of the boron nitride is 200 nm to 10 μm.

[0012] As a further technical solution, the boron nitride is modified boron nitride, and the raw materials for the modified boron nitride include boron nitride, tungsten powder and molybdenum powder.

[0013] In this invention, tungsten powder and molybdenum powder are used together to modify boron nitride, which can improve the chemical activity of boron nitride relative to molten metal, thereby enabling boron nitride to have a better wetting effect on molten metal, further improving the interfacial bonding between boron nitride and the matrix, and further improving the mechanical properties of anchor bolts.

[0014] As a further technical solution, the weight ratio of boron nitride, tungsten powder and molybdenum powder is 90:2 to 4:1.

[0015] When the weight ratio of boron nitride, tungsten powder, and molybdenum powder is 90:2 to 4:1, the mechanical properties of the anchor bolts are further improved.

[0016] As a further technical solution, the preparation method of the modified boron nitride includes the following steps: mixing the boron nitride, the tungsten powder and the molybdenum powder, hot pressing and sintering, and pulverizing to obtain the modified boron nitride.

[0017] As a further technical solution, the hot pressing sintering process is carried out at a temperature of 1500~1600℃, a pressure of 15~25MPa, and a time of 2~3h.

[0018] As a further technical solution, the median particle size of the tungsten powder is 100~200nm, and the median particle size of the molybdenum powder is 50nm~200nm.

[0019] This invention also proposes a method for preparing a high-strength anchor bolt, comprising the following steps:

[0020] S1. Weigh the components according to the weight percentage of the matrix, mix them, and melt them to obtain molten steel;

[0021] S2. Add the reinforcing phase to the molten steel, mix evenly, cast, and mold to obtain a bolt blank;

[0022] S3. The bolt blank is drawn, cold-forged, threaded, and heat-treated, and then cooled to obtain the anchor bolt.

[0023] As a further technical solution, in step S3, the heat treatment temperature is 650~850℃ and the time is 1~2h.

[0024] The working principle and beneficial effects of this invention are as follows:

[0025] In this invention, by optimizing the composition of the matrix in the anchor bolt and introducing a boron nitride reinforcing phase, an anchor bolt with a uniform and stable internal structure and excellent mechanical properties is prepared under the effective action of each component. Specifically, the introduction of Cu, Se, and Sn, through their effective combination, significantly improves the mechanical properties of the anchor bolt. Furthermore, the distribution of the boron nitride reinforcing phase within the anchor bolt ensures uniform stress distribution, thereby enhancing its overall load-bearing capacity and mechanical properties. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] In the following examples and comparative examples, the content of Mn in the iron-manganese alloy is 75 wt%; the content of V in the ferrovanadium alloy is 80 wt%; the content of W in the ferrotungsten powder is 70 wt%; the content of Sn in the tin-manganese alloy is 50 wt%; the content of Cu in the copper-iron alloy is 85 wt%; the content of Fe in the scrap steel is 97.3 wt%; the content of Se in the ferroselenium alloy is 52 wt%; the median particle size of the tungsten powder is 150 nm; the median particle size of the molybdenum powder is 100 nm; and the median particle size of the boron nitride is 10 μm.

[0028] Example 1

[0029] A high-strength anchor bolt comprises a matrix and a reinforcing phase in a weight ratio of 100:2. The matrix consists of the following components in weight percentage: C 0.2%, Mn 0.24%, V 0.12%, W 0.05%, Sn 0.14%, Cu 0.018%, Se 0.018%, P 0.005%, S 0.005%, with the remainder being iron and its unavoidable impurities.

[0030] The reinforcing phase is boron nitride;

[0031] Its preparation method includes the following steps:

[0032] S1. Weigh, mix, and smelt ferromanganese alloy, ferrovanadium alloy, ferrotungsten powder, tin-manganese alloy, ferroselenium alloy, ferrocopper alloy, and scrap steel according to the weight percentage of the matrix to obtain molten steel.

[0033] S2. Add boron nitride to the molten steel, mix evenly, cast, and shape to obtain a bolt blank;

[0034] S3. After the bolt blank is drawn, cold-forged, and threaded, it is heat-treated at 650℃ for 2 hours and then cooled to obtain the anchor bolt.

[0035] Example 2

[0036] A high-strength anchor bolt comprises a matrix and a reinforcing phase in a weight ratio of 100:4. The matrix is ​​composed of the following components in weight percentage: C 0.29%, Mn 0.3%, V 0.15%, W 0.1%, Sn 0.276%, Cu 0.042%, Se 0.042%, P 0.025%, S 0.025%, with the remainder being iron and its unavoidable impurities.

[0037] The reinforcing phase is boron nitride;

[0038] Its preparation method includes the following steps:

[0039] S1. Weigh the iron-manganese alloy, ferrovanadium alloy, ferrotungsten powder, tin-manganese alloy, ferroselenium alloy, ferrocopper alloy, and scrap steel according to the weight percentage of the matrix, mix them, and smelt them to obtain molten steel.

[0040] S2. Add boron nitride to the molten steel, mix evenly, cast, and shape to obtain a bolt blank;

[0041] S3. After the bolt blank is drawn, cold-forged, and threaded, it is heat-treated at 750℃ for 1.5 hours and then cooled to obtain the anchor bolt.

[0042] Example 3

[0043] A high-strength anchor bolt comprises a matrix and a reinforcing phase in a weight ratio of 100:5. The matrix consists of the following components in weight percentage: C 0.38%, Mn 0.35%, V 0.18%, W 0.15%, Sn 0.28%, Cu 0.15%, Se 0.15%, P 0.055%, S 0.045%, with the remainder being iron and its unavoidable impurities.

[0044] The reinforcing phase is boron nitride;

[0045] Its preparation method includes the following steps:

[0046] S1. Weigh the iron-manganese alloy, ferrovanadium alloy, ferrotungsten powder, tin-manganese alloy, ferroselenium alloy, ferrocopper alloy, and scrap steel according to the weight percentage of the matrix, mix them, and smelt them to obtain molten steel.

[0047] S2. Add boron nitride to the molten steel, mix evenly, cast, and shape to obtain a bolt blank;

[0048] S3. After the bolt blank is drawn, cold-forged, and threaded, it is heat-treated at 850℃ for 1 hour and then cooled to obtain the anchor bolt.

[0049] Example 4

[0050] The only difference between this embodiment and Embodiment 2 is that in this embodiment, the weight percentage of Cu added is 0.1%, the weight percentage of Se added is 0.1%, and the weight percentage of Sn added is 0.16%.

[0051] Example 5

[0052] The only difference between this embodiment and Embodiment 2 is that in this embodiment, the weight percentage of Cu added is 0.045%, the weight percentage of Se added is 0.045%, and the weight percentage of Sn added is 0.27%.

[0053] Example 6

[0054] The only difference between this embodiment and Embodiment 2 is that in this embodiment, the weight percentage of Cu added is 0.09%, the weight percentage of Se added is 0.09%, and the weight percentage of Sn added is 0.18%.

[0055] Example 7

[0056] The only difference between this embodiment and Embodiment 6 is that in this embodiment, boron nitride is modified boron nitride, and its preparation method includes the following steps: mixing 90 parts of boron nitride and 2 parts of tungsten powder, hot-pressing and sintering at 1500℃ and 15MPa for 3 hours, and pulverizing to obtain modified boron nitride.

[0057] Example 8

[0058] The only difference between this embodiment and Embodiment 6 is that in this embodiment, boron nitride is modified boron nitride, and its preparation method includes the following steps: mixing 90 parts of boron nitride and 2 parts of molybdenum powder, hot-pressing and sintering at 1600℃ and 25MPa for 2 hours, and pulverizing to obtain modified boron nitride.

[0059] Example 9

[0060] The only difference between this embodiment and Embodiment 6 is that in this embodiment, boron nitride is modified boron nitride, and its preparation method includes the following steps: mixing 90 parts of boron nitride, 1 part of tungsten powder and 1 part of molybdenum powder, hot-pressing and sintering at 1550℃ and 20MPa for 2.5h, and pulverizing to obtain modified boron nitride.

[0061] Example 10

[0062] The only difference between this embodiment and Embodiment 9 is that in this embodiment, 5 parts of tungsten powder are added.

[0063] Example 11

[0064] The only difference between this embodiment and Embodiment 9 is that in this embodiment, 2 parts of tungsten powder are added.

[0065] Example 12

[0066] The only difference between this embodiment and Embodiment 9 is that in this embodiment, 4 parts of tungsten powder are added.

[0067] Comparative Example 1

[0068] The only difference between this comparative example and Example 1 is that Se was not added in this comparative example, the weight percentage of Cu added was 0.036%, and the weight percentage of Sn added was 0.14%.

[0069] Comparative Example 2

[0070] The only difference between this comparative example and Example 1 is that Cu was not added in this comparative example, the weight percentage of Se added was 0.036%, and the weight percentage of Sn added was 0.14%.

[0071] Comparative Example 3

[0072] The only difference between this comparative example and Example 1 is that Cu and Se were not added in this comparative example, and the weight percentage of Sn added was 0.176%.

[0073] Comparative Example 4

[0074] The only difference between this comparative example and Example 1 is that Sn was not added in this comparative example, the weight percentage of Cu added was 0.088%, and the weight percentage of Se added was 0.088%.

[0075] Comparative Example 5

[0076] The only difference between this comparative example and Example 1 is that Cu, Se, and Sn were not added in this comparative example.

[0077] Comparative Example 6

[0078] The only difference between this comparative example and Example 1 is that no boron nitride reinforcing phase was added in this comparative example.

[0079] The anchor bolts prepared in Examples 1-12 and Comparative Examples 1-6 were tested for tensile strength and yield strength according to the test methods in GB / T 228.1-2021 "Metallic materials, tensile testing—Part 1: Test at room temperature," with a test speed of 0.004 s for all tests. -1 The test results for each group are the average of 5 samples.

[0080] Table 1. Mechanical property test results of Examples 1-12 and Comparative Examples 1-6

[0081]

[0082] Compared with Comparative Examples 1-5, the tensile strength and yield strength of Example 1 were significantly improved, indicating that the introduction of Cu, Se, and Sn elements into the anchor bolt matrix has a synergistic effect, which can significantly improve the mechanical properties of the anchor bolt. Compared with Comparative Example 6, the tensile strength and yield strength of Example 1 were significantly improved, indicating that the addition of the boron nitride reinforcing phase can also improve the mechanical properties of the anchor bolt.

[0083] Compared with Examples 2 and 4, the tensile strength and yield strength of Examples 5 and 6 are improved, indicating that the mechanical properties of anchor bolts can be further improved when the weight percentage of Cu and Se is 1 to 3:3 compared with the weight ratio of Sn.

[0084] Compared with Examples 6-8, the tensile strength and yield strength of Examples 9-12 are improved, indicating that modifying boron nitride with tungsten powder and molybdenum powder can further improve the mechanical properties of anchor bolts. Among them, compared with Examples 9-10, the tensile strength and yield strength of Examples 11-12 are improved. When the weight ratio of boron nitride, tungsten powder and molybdenum powder is 90:2 to 4:1, the mechanical properties of anchor bolts are further improved.

[0085] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength anchor bolt, comprising a matrix and a reinforcing phase, characterized in that, The matrix is ​​composed of the following components in weight percentage: C 0.2%~0.38%, Mn 0.24%~0.35%, V 0.12%~0.18%, W 0.05%~0.15%, Sn 0.14%~0.28%, Cu 0.018%~0.15%, Se 0.018%~0.15%, P≤0.055%, S≤0.045%, with the remainder being iron and its unavoidable impurities; The reinforcing phase is boron nitride; The weight ratio of the matrix to the reinforcing phase is 100:2~5; The weight ratio of Cu and Se to Sn is 1~3:3; The boron nitride is modified boron nitride, and the raw materials for the modified boron nitride include boron nitride, tungsten powder, and molybdenum powder.

2. The high-strength anchor bolt according to claim 1, characterized in that, The weight ratio of Cu to Se is 1:

1.

3. A high-strength anchor bolt according to claim 1, characterized in that, The median particle size of the boron nitride is 200 nm to 10 μm.

4. A high-strength anchor bolt according to claim 1, characterized in that, The weight ratio of boron nitride, tungsten powder, and molybdenum powder is 90:2 to 4:

1.

5. A high-strength anchor bolt according to claim 1, characterized in that, The method for preparing the modified boron nitride includes the following steps: mixing the boron nitride, the tungsten powder and the molybdenum powder, hot-pressing and sintering, and pulverizing to obtain the modified boron nitride.

6. A high-strength anchor bolt according to claim 5, characterized in that, During the hot pressing sintering process, the temperature is 1500~1600℃, the pressure is 15~25MPa, and the time is 2~3h.

7. A method for preparing a high-strength anchor bolt according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Weigh the components according to the weight percentage of the matrix, mix them, and melt them to obtain molten steel; S2. Add the reinforcing phase to the molten steel, mix evenly, cast, and mold to obtain a bolt blank; S3. The bolt blank is drawn, cold-forged, threaded, and heat-treated, and then cooled to obtain the anchor bolt.

8. The method for preparing a high-strength anchor bolt according to claim 7, characterized in that, In step S3, the heat treatment is performed at a temperature of 650~850℃ for 1~2 hours.

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