Titanium alloy material for high-temperature anti-titanium oxide welding pipe

Abstract

The invention relates to the technical field of alloy materials, and provides a titanium alloy material for a high-temperature antioxidant titanium welding pipe, the titanium alloy material comprises a titanium alloy matrix and a reinforcing phase, the titanium alloy matrix comprises the following components: Sn, Nb, Zr, Al, Si, Cr, Mo, Mn, O, C, N, H, and the balance Ti and inevitable impurities; the reinforcement phase includes silicon carbide. According to the technical scheme, the problem that the high-temperature oxidation resistance of a titanium alloy material in the service process of 600 DEG C or above in the prior art is sharply reduced is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to a titanium alloy material for high-temperature oxidation-resistant titanium welded pipes. Background Art

[0002] Compared with other metals, titanium has superior corrosion resistance and is widely used in the chemical industry, petroleum industry, power plants, seawater desalination and other fields. At present, the use of titanium welded pipes is very common. Titanium welded pipes are pipes made of titanium alloy plates or strips through bending or spinning and then welding. They have the characteristics of light weight, high strength and excellent mechanical properties. They are widely used in heat exchange equipment, coil heat exchangers, serpentine heat exchangers, condensers, evaporators and pipelines.

[0003] With the continuous advancement of technology, titanium welded pipes can no longer meet demand in some aspects. For example, the high-temperature oxidation resistance of titanium alloy materials drops sharply when in service above 600°C, resulting in poor high-temperature oxidation resistance of the produced titanium welded pipes. Summary of the Invention

[0004] The present invention provides a titanium alloy material for high-temperature oxidation-resistant titanium welded pipes, which solves the problem in the related art that the high-temperature oxidation resistance of titanium alloy materials decreases sharply during service at temperatures above 600°C.

[0005] The technical solutions of the present invention are as follows: A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcing phase, wherein the titanium alloy matrix is ​​composed of the following components in percentage by mass: Sn: 1.6%-3.3%, Nb: 0.36%-1.8%, Zr: 3.2%-4.7%, Al: 4.1%-6.5%, Si: 0.1%-0.25%, Cr: 0.02%-0.25%, Mo: 1.8%-3.2%, Mn: 0.03%-0.2%, O: ≤0.1%, C: ≤0.05%, N: ≤0.05%, H: ≤0.01%, and the balance is Ti and unavoidable impurities; the reinforcing phase comprises silicon carbide.

[0006] As a further technical solution, in terms of mass percentage, 0.1≤(6Cr-0.7Mn) / (Mo+0.15Cr)≤0.25.

[0007] In the present invention, the contents of Cr, Mo, and Mn are optimized to meet the requirement of 0.1≤(6Cr-0.7Mn) / (Mo+0.15Cr)≤0.25 in terms of mass percentage, thereby further improving the high-temperature oxidation resistance of the titanium alloy material.

[0008] In the present invention, the ratio of the amount of the reinforcing phase can be any conventional amount in the art, preferably the mass ratio of the titanium alloy matrix and the reinforcing phase is 100:1~4, for example, it can be 100:1, 100:1.5, 100:2, 100:2.5, 100:3, 100:3.5 or 100:4, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0009] As a further technical solution, the silicon carbide includes pretreated silicon carbide, and the pretreated silicon carbide is aluminum oxide composite silicon carbide.

[0010] In the present invention, alumina composited with silicon carbide is used as the reinforcing phase. After the silicon carbide is composited with alumina, the wettability of the reinforcing phase and the titanium alloy matrix is ​​improved. In addition, the thermal expansion coefficients of alumina and the titanium alloy matrix are similar, which reduces the thermal stress caused by the mismatch of the thermal expansion coefficients between the titanium alloy matrix and the reinforcing phase, makes the interface between the two stable, and achieves the effect of improving the tensile strength of the titanium alloy material.

[0011] As a further technical solution, the raw materials of the alumina-silicon carbide composite include alumina and silicon carbide in a mass ratio of 1 to 5:100.

[0012] As a further technical solution, the particle size of the aluminum oxide is nanometer-scale; the particle size of the silicon carbide is micrometer-scale.

[0013] In the present invention, the aluminum oxide can be any one or more conventional nano-scale aluminum oxides in the art, preferably aluminum oxide with a particle size of 20 to 500 nm, for example, 20 nm, 30 nm, 50 nm, 100 nm, 150 nm, 200 nm, 300 nm or 500 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] In the present invention, silicon carbide can be any one or more conventional micron-sized silicon carbide in the art, preferably silicon carbide with a particle size of 1 to 10 μm, for example, it can be 1 μm, 2 μm, 3 μm, 5 μm, 8 μm or 10 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] As a further technical solution, the preparation method of the aluminum oxide composite silicon carbide comprises the following steps: mixing aluminum oxide and silicon carbide, and then ball milling to obtain the aluminum oxide composite silicon carbide.

[0016] In the present invention, after aluminum oxide and silicon carbide are mixed, nano-aluminum oxide can be coated on the surface of micron-sized silicon carbide by ball milling. When used as a reinforcing phase, the wettability of the reinforcing phase and the titanium alloy matrix is ​​improved, so that the reinforcing phase can fully play its role, thereby improving the tensile strength of the titanium alloy material. In addition, the ball milling can adopt any conventional process parameters in the art, preferably a ball milling speed of 300 to 700 rpm, for example, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, 650 rpm or 700 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable. The ball milling time is 3 to 5 h, for example, 3 h, 3.5 h, 4 h, 4.5 h or 5 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] As a further technical solution, the silicon carbide is titanium carbide composite pretreated silicon carbide.

[0018] In the present invention, titanium carbide composite pre-treated silicon carbide is used as a reinforcing phase, which improves the stability of the reinforcing phase in the titanium alloy matrix and further improves the tensile strength of the titanium alloy material.

[0019] As a further technical solution, the raw materials for the titanium carbide composite pretreatment of silicon carbide include aluminum oxide, titanium carbide and silicon carbide in a mass ratio of 1-2:3-4:100.

[0020] As a further technical solution, the particle size of the titanium carbide is nanometer-scale.

[0021] In the present invention, the titanium carbide can be any one or more conventional nano-scale titanium carbides in the art, preferably titanium carbide with a particle size of 40 to 800 nm, for example, 40 nm, 50 nm, 80 nm, 500 nm or 800 nm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0022] As a further technical solution, the method for preparing titanium carbide composite pretreated silicon carbide includes the following steps: mixing aluminum oxide and silicon carbide, and then ball milling; adding titanium carbide and continuing ball milling to obtain titanium carbide composite pretreated silicon carbide.

[0023] In the present invention, aluminum oxide and silicon carbide are first mixed, then ball-milled to coat the surface of micron-sized silicon carbide with nano-aluminum oxide. Titanium carbide is then added and ball-milled to coat the nano-sized titanium carbide as the outermost layer. When used as a reinforcement phase, while ensuring similar thermal expansion coefficients between the reinforcement phase and the titanium alloy matrix, the stability of the reinforcement phase within the titanium alloy matrix is ​​also guaranteed, allowing the reinforcement phase to fully function, thereby further improving the tensile strength of the titanium alloy material. In addition, the ball milling can adopt any conventional process parameters in the art, preferably the ball milling speed is 300~700rpm, for example, it can be 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, 650rpm or 700rpm, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable. The ball milling time is 3~5h, for example, it can be 3h, 3.5h, 4h, 4.5h or 5h, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0024] The working principle and beneficial effects of the present invention are: The present invention provides a titanium alloy material for high-temperature oxidation-resistant titanium welded pipes, comprising a titanium alloy matrix and a reinforcement phase. The titanium alloy matrix is ​​composed of Sn, Nb, Zr, Al, Si, Cr, Mo, Mn, O, C, N, H, Ti, and unavoidable impurities. The high-temperature oxidation resistance of the titanium alloy is enhanced by the addition of Cr, Mo, and Mn and by optimizing the content of each component. Furthermore, the reinforcement phase includes silicon carbide, which has high strength, high hardness, excellent thermal stability, and excellent oxidation resistance. Its use as a reinforcement phase further improves the high-temperature oxidation resistance of the titanium alloy. 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 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.

[0026] The parameters of the raw materials in the following examples and comparative examples are as follows: The particle size of alumina is 30nm and the specific surface area is 50m 2 / g; The particle size of titanium carbide is 40nm and the specific surface area is 65m 2 / g; The particle size of silicon carbide is 8μm and the specific surface area is 8m 2 / g.

[0027] The titanium alloy material for high-temperature oxidation-resistant titanium welded pipes in the following examples and comparative examples was prepared by the following method: S1. After preparing the materials according to the components of the titanium alloy matrix, mixing them evenly, pressing the electrodes, vacuum welding the electrodes, smelting them in a vacuum consumable arc furnace at 1700° C. for 45 minutes, adding the reinforcing phase and blending them, and casting to obtain a titanium alloy ingot; S2. Forging the titanium alloy ingot and subjecting it to heat treatment to obtain a titanium alloy material for high-temperature oxidation-resistant titanium welded pipes.

[0028] Example 1 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase with a mass ratio of 100:1, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 1.6%, Nb: 0.36%, Zr: 3.2%, Al: 4.1%, Si: 0.1%, Cr: 0.02%, Mo: 1.8%, Mn: 0.03%, O: 0.05%, C: 0.02%, N: 0.01%, H: 0.003%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0029] Example 2 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.1%, Mo: 2.7%, Mn: 0.13%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0030] Example 3 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:5, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 3.3%, Nb: 1.8%, Zr: 4.7%, Al: 6.5%, Si: 0.25%, Cr: 0.25%, Mo: 3.2%, Mn: 0.2%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0031] Example 4 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.05%, Mo: 2.5725%, Mn: 0.06%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0032] Example 5 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.14%, Mo: 2.835%, Mn: 0.18%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0033] Example 6 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes includes a titanium alloy matrix and a reinforcement phase with a mass ratio of 100:3. The titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.03%, Mo: 3%, Mn: 0.17%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0034] Example 7 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.25%, Mo: 1.8%, Mn: 0.05%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0035] Example 8 The only difference from Example 2 is that the reinforcement phase is aluminum oxide composite silicon carbide; The preparation method of aluminum oxide composite silicon carbide is as follows: aluminum oxide and silicon carbide are mixed in a mass ratio of 1:20, and ball milled at 300 rpm for 5 hours to obtain aluminum oxide composite silicon carbide.

[0036] Example 9 The only difference from Example 2 is that the reinforcement phase is aluminum oxide composite silicon carbide; The preparation method of aluminum oxide composite silicon carbide is as follows: aluminum oxide and silicon carbide are mixed in a mass ratio of 1:100, and ball milled at 700 rpm for 3 hours to obtain aluminum oxide composite silicon carbide.

[0037] Example 10 The only difference from Example 8 is that the aluminum oxide is replaced by equal amounts of aluminum oxide and titanium carbide in a mass ratio of 1:4.

[0038] Example 11 The only difference from Example 8 is that the aluminum oxide is replaced by equal amounts of aluminum oxide and titanium carbide in a mass ratio of 2:3.

[0039] Example 12 The only difference from Example 11 is that the reinforcement phase is titanium carbide composite pretreated silicon carbide; The preparation method of titanium carbide composite pretreated silicon carbide is as follows: after mixing aluminum oxide and silicon carbide, ball milling at 300 rpm for 3 hours; adding titanium carbide and continuing ball milling for 2 hours to obtain titanium carbide composite pretreated silicon carbide, wherein the mass ratio of aluminum oxide, titanium carbide and silicon carbide is 2:3:100.

[0040] Example 13 The only difference from Example 11 is that the reinforcement phase is titanium carbide composite pretreated silicon carbide; The preparation method of titanium carbide composite pretreated silicon carbide is as follows: titanium carbide and silicon carbide are mixed, and ball milled at 300 rpm for 3 hours; aluminum oxide is added and ball milled for 2 hours to obtain titanium carbide composite pretreated silicon carbide, wherein the mass ratio of aluminum oxide, titanium carbide and silicon carbide is 2:3:100.

[0041] Comparative Example 1 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Mo: 2.85%, Mn: 0.18%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0042] Comparative Example 2 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 1.45%, Mn: 1.48%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0043] Comparative Example 3 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes comprises a titanium alloy matrix and a reinforcement phase in a mass ratio of 100:3, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.165%, Mo: 2.765%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase is silicon carbide.

[0044] Comparative Example 4 A titanium alloy material for high-temperature oxidation-resistant titanium welded pipes is composed of the following components in percentage by mass: Sn: 2.1%, Nb: 0.95%, Zr: 3.8%, Al: 5.4%, Si: 0.17%, Cr: 0.1%, Mo: 2.7%, Mn: 0.13%, O: 0.1%, C: 0.05%, N: 0.05%, H: 0.01%, and the balance being Ti and unavoidable impurities.

[0045] Performance testing: (1) High temperature oxidation resistance: The titanium alloy material was heat treated at 750℃ for 1000h. During this period, the material was weighed using a precision electronic balance every 200h. The test results are recorded in Table 1. (2) Tensile strength: The room temperature tensile strength of the titanium alloy material was tested according to the method in GB / T 228.1-2021. The test results are recorded in Table 2.

[0046] Table 1 High temperature oxidation resistance test results

[0047] As shown in Table 1, the titanium alloy materials obtained in Examples 1-7 exhibited lower oxidation weight gains after heat treatment at 750°C for 1000 hours than those in Comparative Examples 1-4, indicating that the addition of Cr, Mo, and Mn, the optimization of the content of each component, and the use of silicon carbide as a reinforcing phase improved the high-temperature oxidation resistance of the titanium alloy materials. Furthermore, the titanium alloy materials obtained in Examples 2 and Examples 4-5 exhibited lower oxidation weight gains after heat treatment at 750°C for 1000 hours than those in Examples 6-7, indicating that the Cr, Mo, and Mn contents satisfied the requirement of 0.1 ≤ (6Cr - 0.7Mn) / (Mo + 0.15Cr) ≤ 0.25, further enhancing the high-temperature oxidation resistance of the titanium alloy materials.

[0048] Table 2 Tensile strength test results

[0049] As can be seen from Table 2, the tensile strength of the titanium alloy materials obtained in Examples 8 to 13 is higher than that of Example 2, indicating that the use of aluminum oxide composited with silicon carbide as a reinforcement phase improves the tensile strength of the titanium alloy materials. In addition, the tensile strength of the titanium alloy materials obtained in Examples 10 to 13 is higher than that of Examples 8 to 9, indicating that the use of titanium carbide composited with pretreated silicon carbide as a reinforcement phase further improves the tensile strength of the titanium alloy materials.

[0050] 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 titanium alloy material for high-temperature oxidation-resistant titanium welded pipe, characterized in that: The invention comprises a titanium alloy matrix and a reinforcement phase, wherein the titanium alloy matrix is ​​composed of the following components in mass percentage: Sn: 1.6%~3.3%, Nb: 0.36%~1.8%, Zr: 3.2%~4.7%, Al: 4.1%~6.5%, Si: 0.1%~0.25%, Cr: 0.02%~0.25%, Mo: 1.8%~3.2%, Mn: 0.03%~0.2%, O: ≤0.1%, C: ≤0.05%, N: ≤0.05%, H: ≤0.01%, and the balance is Ti and unavoidable impurities; the reinforcement phase comprises silicon carbide.

2. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 1, characterized in that: In terms of mass percentage, 0.1≤(6Cr-0.7Mn) / (Mo+0.15Cr)≤0.

25.

3. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 1, characterized in that: The silicon carbide includes pretreated silicon carbide, and the pretreated silicon carbide is aluminum oxide composite silicon carbide.

4. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 3, characterized in that: The raw materials of the aluminum oxide composite silicon carbide include aluminum oxide and silicon carbide in a mass ratio of 1 to 5:

100.

5. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 4, characterized in that: The particle size of the aluminum oxide is nanometer-level; the particle size of the silicon carbide is micrometer-level.

6. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 5, characterized in that: The preparation method of the aluminum oxide composite silicon carbide comprises the following steps: mixing aluminum oxide and silicon carbide, and then ball milling to obtain the aluminum oxide composite silicon carbide.

7. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 3, characterized in that: The silicon carbide is titanium carbide composite pretreated silicon carbide.

8. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 7, characterized in that: The raw materials for the titanium carbide composite pretreatment of silicon carbide include aluminum oxide, titanium carbide and silicon carbide in a mass ratio of 1-2:3-4:

100.

9. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 8, characterized in that: The particle size of the titanium carbide is nanometer level.

10. The titanium alloy material for high-temperature oxidation-resistant titanium welded pipe according to claim 9, characterized in that: The preparation method of titanium carbide composite pretreated silicon carbide comprises the following steps: mixing aluminum oxide and silicon carbide, and then ball milling; adding titanium carbide and continuing ball milling to obtain titanium carbide composite pretreated silicon carbide.

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