Steel for fire-resistant and anti-seismic bracket as well as preparation method and application of steel

Abstract

The invention relates to the technical field of steel for buildings, and provides steel for a fire-resistant anti-seismic support and a preparation method and application of the steel. Steel for a fire-resistant and shock-resistant support comprises an iron matrix and a reinforcing phase, the iron matrix is composed of C, Si, Mn, Cr, B, P, N, Nb, Cu, Ni, Mo, Ti, V, W, Co, S, iron and inevitable impurities, and the reinforcing phase is titanium carbide. According to the technical scheme, the problems of poor fire resistance and shock resistance of the steel for the bracket in the related technology are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of building steel, and in particular to a fire-resistant and earthquake-resistant support steel and a preparation method and application thereof. Background Art

[0002] In the construction industry, it is inevitable to use supports, such as pipe supports, boiler supports and other steel structures. They not only need to have good fire resistance, but also be able to withstand high temperature environments without quickly losing structural strength in the event of a fire, so that the supports can continue to play a certain supporting role for a certain period of time. They also need to have seismic resistance, which is mainly reflected in having high strength and good toughness, and being able to effectively resist deformation and damage in the event of an earthquake, so as to absorb and disperse seismic energy.

[0003] In the field of construction, fire-resistant and earthquake-resistant support steel has a wide range of market applications. As people pay more and more attention to residential safety, higher requirements are placed on the fire resistance and earthquake resistance of existing fire-resistant and earthquake-resistant support steel. Summary of the invention

[0004] The present invention provides a fire-resistant and earthquake-resistant support steel, a preparation method and an application thereof, which solve the problem of poor fire resistance and earthquake resistance of the support steel in the related art.

[0005] The technical solution of the present invention is as follows: A steel for fire-resistant and earthquake-resistant brackets, comprising an iron matrix and a reinforcement phase, wherein the iron matrix is ​​composed of the following components in mass percentage: C: 0.06%-0.09%, Si: 0.2%-0.3%, Mn: 1.45%-1.55%, Cr: 0.35%-0.45%, B: 0.001%-0.003%, P: 0.001%-0.005%, N: 0.005%-0.01%, Nb: 0.001%-0.003%, P: 0.001%-0.005%, N: 0.005%-0.01%, Nb: 0.001%-0.003%, Nb: 0.001%-0.003%, Nb: 0.001%-0.005 ...3%, N .003%~0.008%, Cu: 0.1%~0.25%, Ni: 0.25%~0.35%, Mo: 0.2%~0.3%, Ti: 0.01%~0.02%, V: 0.035%~0.055%, W: 0.002%~0.005%, Co: 0.03%~0.1%, S<0.001%, the rest are iron and unavoidable impurities, and the reinforcing phase is titanium carbide.

[0006] As a further technical solution, the mass ratio of the iron matrix to the reinforcement phase is 100:1~3.

[0007] As a further technical solution, in terms of mass percentage, 30≤(Co+0.6Cu) / (5W-2.3Nb)≤50.

[0008] The present invention limits 30≤(Co+0.6Cu) / (5W-2.3Nb)≤50, which further improves the fire resistance and earthquake resistance of the steel for the bracket.

[0009] As a further technical solution, the reinforcing phase is modified titanium carbide, and the modifier of the modified titanium carbide includes tungsten carbide and / or silicon carbide.

[0010] The present invention uses tungsten carbide and / or silicon carbide modified titanium carbide as a reinforcing phase, thereby further improving the fire resistance and earthquake resistance of the steel for the bracket.

[0011] As a further technical solution, the mass ratio of the modifier to titanium carbide is 5~15:100.

[0012] As a further technical solution, the modifier for modifying titanium carbide includes tungsten carbide and silicon carbide in a mass ratio of 1:9 to 9:1.

[0013] The present invention further improves the fire resistance and earthquake resistance of the steel for the bracket by using tungsten carbide and silicon carbide with a mass ratio of 1:9 to 9:1 as modifiers to modify titanium carbide as a reinforcing phase.

[0014] As a further technical solution, the mass of the tungsten carbide is ≤ the mass of the silicon carbide.

[0015] The present invention limits the mass of tungsten carbide to less than the mass of silicon carbide, thereby further improving the fire resistance and earthquake resistance of the steel for the bracket.

[0016] As a further technical solution, the mass ratio of the tungsten carbide to the silicon carbide is 4:6~3:7.

[0017] The present invention limits the mass ratio of tungsten carbide to silicon carbide to 4:6-3:7, thereby further improving the fire resistance and earthquake resistance of the steel for the bracket.

[0018] As a further technical solution, the silicon carbide is silicon carbide nanowires.

[0019] The present invention limits the silicon carbide to silicon carbide nanowires, which further improves the fire resistance and earthquake resistance of the steel for the bracket.

[0020] As a further technical solution, the silicon carbide nanowire has a diameter of 50 nm and a length of 20 μm.

[0021] As a further technical solution, the method for preparing modified silicon carbide comprises the following steps: mixing the modifier with silicon carbide, and then grinding to obtain modified silicon carbide.

[0022] The present invention also proposes a method for preparing steel for fire-resistant and earthquake-resistant brackets, comprising the following steps: S1. After materials are prepared according to the composition of the iron matrix, molten steel is obtained through smelting and refining; S2, adding a reinforcing phase to the molten steel and dispersing it uniformly, and then die-casting to obtain a steel billet; S3. The steel billet is subjected to heat treatment to obtain steel for fire-resistant and earthquake-resistant brackets.

[0023] The present invention also proposes the use of the fire-resistant and earthquake-resistant support steel or the fire-resistant and earthquake-resistant support steel prepared by the preparation method on a support.

[0024] The working principle and beneficial effects of the present invention are: The present invention provides a fire-resistant and earthquake-resistant support steel, comprising an iron matrix and a reinforcement phase, wherein the iron matrix is ​​composed of C, Si, Mn, Cr, B, P, N, Nb, Cu, Ni, Mo, Ti, V, W, Co, S and iron and inevitable impurities, and the reinforcement phase is titanium carbide. The fire resistance and earthquake resistance of the support steel are improved by coordinating the elements and optimizing the dosage of each component. DETAILED DESCRIPTION

[0025] 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 described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The parameters of the raw materials in the following examples and comparative examples are as follows: The particle size of titanium carbide is 1 μm; The particle size of tungsten carbide is 400nm; The particle size of silicon carbide powder is 50nm; The diameter of the silicon carbide nanowire is 50 nm and the length is 20 μm.

[0027] Example 1 A steel for fire-resistant and earthquake-resistant brackets, comprising an iron matrix and a reinforcement phase with a mass ratio of 100:3, wherein the iron matrix is ​​composed of the following components in mass percentage: C: 0.08%, Si: 0.25%, Mn: 1.51%, Cr: 0.39%, B: 0.0017%, P: 0.0026%, N: 0.0072%, Nb: 0.0045%, Cu: 0.15%, Ni: 0.31%, Mo: 0.25%, Ti: 0.018%, V: 0.041%, W: 0.0033%, Co: 0.078%, S: 0.0004%, and the rest are iron and unavoidable impurities, and the reinforcement phase is titanium carbide; The preparation process comprises the following steps: S1. After materials are prepared according to the composition of the iron matrix, molten steel is obtained through smelting and refining; S2, adding the reinforcing phase to the molten steel and dispersing it uniformly, and then die-casting to obtain a steel billet; S3. Quench the steel billet at 900°C for 3 hours, and temper it at 500°C for 7 hours to obtain fire-resistant and earthquake-resistant support steel.

[0028] Example 2 The only difference from Example 1 is: A steel for fire-resistant and earthquake-resistant supports comprises an iron matrix and a reinforcement phase in a mass ratio of 100:1, wherein the iron matrix is ​​composed of the following components in mass percentage: C: 0.06%, Si: 0.2%, Mn: 1.45%, Cr: 0.35%, B: 0.001%, P: 0.001%, N: 0.005%, Nb: 0.004%, Cu: 0.2%, Ni: 0.25%, Mo: 0.2%, Ti: 0.01%, V: 0.035%, W: 0.003%, Co: 0.03%, S: 0.0009%, and the rest are iron and unavoidable impurities, and the reinforcement phase is titanium carbide.

[0029] Example 3 The only difference from Example 1 is: A steel for fire-resistant and earthquake-resistant supports comprises an iron matrix and a reinforcement phase in a mass ratio of 100:2, wherein the iron matrix is ​​composed of the following components in mass percentage: C: 0.09%, Si: 0.3%, Mn: 1.55%, Cr: 0.45%, B: 0.003%, P: 0.005%, N: 0.01%, Nb: 0.006%, Cu: 0.25%, Ni: 0.35%, Mo: 0.3%, Ti: 0.02%, V: 0.055%, W: 0.004%, Co: 0.1%, S: 0.0001%, and the rest are iron and unavoidable impurities, and the reinforcement phase is titanium carbide.

[0030] Example 4 The only difference from Example 1 is: A steel for a fire-resistant and earthquake-resistant support comprises an iron matrix and a reinforcement phase in a mass ratio of 100:3, wherein the iron matrix is ​​composed of the following components in mass percentage: C: 0.08%, Si: 0.25%, Mn: 1.51%, Cr: 0.39%, B: 0.0017%, P: 0.0026%, N: 0.0072%, Nb: 0.008%, Cu: 0.1%, Ni: 0.31%, Mo: 0.25%, Ti: 0.018%, V: 0.041%, W: 0.005%, Co: 0.03%, S: 0.0004%, and the rest are iron and unavoidable impurities, and the reinforcement phase is titanium carbide.

[0031] Example 5 The only difference from Example 1 is: A steel for a fire-resistant and earthquake-resistant support comprises an iron matrix and a reinforcement phase in a mass ratio of 100:3, wherein the iron matrix is ​​composed of the following components in mass percentage: C: 0.08%, Si: 0.25%, Mn: 1.51%, Cr: 0.39%, B: 0.0017%, P: 0.0026%, N: 0.0072%, Nb: 0.003%, Cu: 0.25%, Ni: 0.31%, Mo: 0.25%, Ti: 0.018%, V: 0.041%, W: 0.002%, Co: 0.1%, S: 0.0004%, and the rest are iron and unavoidable impurities, and the reinforcement phase is titanium carbide.

[0032] Example 6 The only difference from Example 1 is that the reinforcing phase is silicon carbide powder and titanium carbide in a mass ratio of 1:10.

[0033] Example 7 The only difference from Example 6 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is: after mixing 1 part of silicon carbide powder with 10 parts of titanium carbide, grinding them at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0034] Example 8 The only difference from Example 7 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is: after mixing 1 part of tungsten carbide with 10 parts of titanium carbide, grinding them at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0035] Example 9 The only difference from Example 7 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is: 0.9 parts of tungsten carbide, 0.1 parts of silicon carbide powder and 10 parts of titanium carbide are mixed, and then ground at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0036] Example 10 The only difference from Example 9 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is: 0.5 parts of tungsten carbide, 0.5 parts of silicon carbide powder and 10 parts of titanium carbide are mixed, and then ground at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0037] Embodiment 11 The only difference from Example 9 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is as follows: 0.4 parts of tungsten carbide, 0.6 parts of silicon carbide powder and 10 parts of titanium carbide are mixed, and then ground at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0038] Example 12 The only difference from Example 9 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is: 0.3 parts of tungsten carbide, 0.7 parts of silicon carbide powder and 10 parts of titanium carbide are mixed, and then ground at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0039] Embodiment 13 The only difference from Example 9 is that the reinforcing phase is modified titanium carbide, and the preparation method of the modified titanium carbide is: 0.1 parts of tungsten carbide, 0.9 parts of silicon carbide powder and 10 parts of titanium carbide are mixed, and then ground at a ball mill speed of 400r / min for 20min to obtain modified titanium carbide.

[0040] Embodiment 14 The only difference from Example 12 is that the reinforcing phase is modified titanium carbide. The preparation method of the modified titanium carbide is as follows: 0.3 parts of tungsten carbide, 0.7 parts of silicon carbide nanowires and 10 parts of titanium carbide are mixed, and then ground at a ball mill speed of 400 r / min for 20 minutes to obtain modified titanium carbide.

[0041] The steel for fire-resistant and earthquake-resistant brackets obtained in Examples 1 to 14 was subjected to a high temperature resistance test at 600°C for 2h, and the lower yield strength before and after high temperature treatment was tested with reference to method B in GB / T228.1-2021. The change rate was calculated according to the following formula to evaluate the fire resistance; the impact performance KV at -20°C was tested with reference to the method in GB / T 229-2020 2 Used to evaluate earthquake resistance; Change rate (%) = (lower yield strength before high temperature treatment - lower yield strength after high temperature treatment) / lower yield strength before high temperature treatment × 100; The results are recorded in Table 1.

[0042] Table 1 Fire resistance and seismic resistance of steel used for fire-resistant and seismic support

[0043] It can be seen from Table 1 that the steel for fire-resistant and earthquake-resistant brackets provided by the present invention has a lower yield strength of more than 731 MPa before high-temperature treatment, a change rate of less than 29% after high-temperature treatment, and an impact performance of more than 81 J at -20°C, and has good fire resistance and earthquake resistance.

[0044] The change rate of the fire-resistant and earthquake-resistant bracket steel obtained in Examples 1 to 3 after high-temperature treatment is lower than that in Examples 4 to 5, and the -20°C impact performance is higher than that in Examples 4 to 5, indicating that when 30≤(Co+0.6Cu) / (5W-2.3Nb)≤50, the fire resistance and earthquake resistance of the bracket steel can be further improved.

[0045] The change rate of the fire-resistant and earthquake-resistant bracket steel obtained in Examples 7 to 14 after high-temperature treatment is lower than that in Example 1 and Example 6, and the -20°C impact performance is higher than that in Example 1 and Example 6, indicating that when tungsten carbide and / or silicon carbide modified titanium carbide is used as a reinforcing phase, the fire resistance and earthquake resistance of the bracket steel can be further improved.

[0046] The change rate of the fire-resistant and earthquake-resistant bracket steel obtained in Examples 9 to 14 after high-temperature treatment is lower than that in Examples 7 to 8, and the -20°C impact performance is higher than that in Examples 7 to 8, indicating that the fire resistance and earthquake resistance of the bracket steel can be further improved by modifying titanium carbide as a reinforcing phase with tungsten carbide and silicon carbide in a mass ratio of 1:9 to 9:1 as modifiers.

[0047] The change rate of the fire-resistant and earthquake-resistant bracket steel obtained in Examples 10 to 14 after high-temperature treatment is lower than that in Example 9, and the -20°C impact performance is higher than that in Example 9, indicating that when the mass of tungsten carbide is ≤ the mass of silicon carbide, the fire resistance and earthquake resistance of the bracket steel can be further improved.

[0048] The change rate of the fire-resistant and earthquake-resistant bracket steel obtained in Examples 11 to 12 after high-temperature treatment is lower than that in Examples 10 and 13, and the -20°C impact performance is higher than that in Examples 10 and 13, indicating that limiting the mass ratio of tungsten carbide to silicon carbide to 4:6 to 3:7 can further improve the fire resistance and earthquake resistance of the bracket steel.

[0049] The change rate of the fire-resistant and earthquake-resistant bracket steel obtained in Example 14 after high-temperature treatment is lower than that in Example 12, and the -20°C impact performance is higher than that in Example 12, indicating that when silicon carbide is silicon carbide nanowires, the fire resistance and earthquake resistance of the bracket steel can be further improved.

[0050] The above are only 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 in the protection scope of the present invention.

Claims

1. A steel for fire-resistant and earthquake-resistant support, characterized in that: It includes an iron matrix and a reinforcement phase, wherein the iron matrix is ​​composed of the following components in mass percentage: Composition: C: 0.06%~0.09%, Si: 0.2%~0.3%, Mn: 1.45%~1.55%, Cr: 0.35%~0.45%, B: 0.001%~0.003%, P: 0.001%~0.005%, N: 0.005%~0.01%, Nb: 0.003%~0.008%, Cu: 0.1%~0.25%, Ni: 0.25%~0.35%, Mo: 0.2%~0.3%, Ti: 0.01%~0.02%, V: 0.035%~0.055%, W: 0.002%~0.005%, Co: 0.03%~0.1%, S<0.001%, the rest are iron and unavoidable impurities, and the reinforcing phase is titanium carbide.

2. The fire-resistant and earthquake-resistant support steel according to claim 1, characterized in that: In terms of mass percentage, 30≤(Co+0.6Cu) / (5W-2.3Nb)≤50.

3. The fire-resistant and earthquake-resistant support steel according to claim 1, characterized in that: The reinforcing phase is modified titanium carbide, and the modifier of the modified titanium carbide includes tungsten carbide and / or silicon carbide.

4. The fire-resistant and earthquake-resistant support steel according to claim 3, characterized in that: The mass ratio of the modifier to titanium carbide is 5-15:

100.

5. The fire-resistant and earthquake-resistant support steel according to claim 4, characterized in that: The modifier includes tungsten carbide and silicon carbide in a mass ratio of 1:9 to 9:

1.

6. The fire-resistant and earthquake-resistant support steel according to claim 5, characterized in that: The mass of the tungsten carbide is ≤ the mass of the silicon carbide.

7. The fire-resistant and earthquake-resistant support steel according to claim 6, characterized in that: The mass ratio of the tungsten carbide to the silicon carbide is 4:6 to 3:

7.

8. The fire-resistant and earthquake-resistant support steel according to claim 7, characterized in that: The silicon carbide is silicon carbide nanowire.

9. A method for preparing fire-resistant and earthquake-resistant support steel according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. After materials are prepared according to the composition of the iron matrix, molten steel is obtained through smelting and refining; S2, adding a reinforcing phase to the molten steel and dispersing it uniformly, and then die-casting to obtain a steel billet; S3. The steel billet is subjected to heat treatment to obtain steel for fire-resistant and earthquake-resistant brackets.

10. Use of the fire-resistant and earthquake-resistant support steel according to any one of claims 1 to 8 or the fire-resistant and earthquake-resistant support steel prepared by the preparation method according to claim 9 in a support.

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