Titanium alloy material for heat-resistant titanium welded pipe

Abstract

The application relates to the technical field of titanium alloy materials, and discloses a titanium alloy material for heat-resistant titanium welded pipes, which comprises a base alloy and a reinforcing phase in a mass ratio of 100:0.5-1.5; the base alloy is composed of the following components in percentage by weight: V 1.5-2.0%, Al 3.6-4.0%, Cr 1.0-1.8%, Zr 1.5-2.5%, Si 0.5-1.0%, Sn 0.5-1.2%, Mo 1.2-2.0%, C<=0.1%, B 0.04-0.2%, Sm 0.02-0.05%, Nb 0.1-0.15%, Er 0.04-0.18%, and the balance is Ti and inevitable impurities; and the reinforcing phase is zirconium oxide. Through the technical scheme, the problem of poor heat resistance of the titanium alloy material for titanium welded pipes in the related art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium alloy materials, in particular to a titanium alloy material for heat-resistant titanium welded pipes. BACKGROUND

[0002] Titanium alloy is widely used in high-temperature pipelines in the fields of aerospace, energy and chemical industry, shipbuilding, etc. due to its high strength, low density, excellent corrosion resistance and good weldability. Especially in high-temperature environments, the heat resistance of titanium alloy becomes a key factor determining its application range. However, traditional titanium alloy often has problems such as grain growth and unstable structure under high-temperature conditions. Long-term use under high temperature will cause changes in microstructure such as grain coarsening, resulting in a significant decrease in mechanical properties such as tensile strength. Especially in severe working conditions above 600℃, the strength retention rate is often less than 70%, which is difficult to meet the load-bearing requirements of high-pressure high-temperature pipelines.

[0003] Therefore, it is of great significance to develop a titanium alloy material with excellent heat resistance, high structure stability and suitable for welding, which can expand the application range of titanium alloy materials and improve their service life. SUMMARY

[0004] The present application provides a titanium alloy material for heat-resistant titanium welded pipes, which solves the problem of poor heat resistance of titanium alloy materials for titanium welded pipes in related technologies.

[0005] The technical scheme of the present application is as follows:

[0006] The present application provides a titanium alloy material for heat-resistant titanium welded pipes, which includes a base alloy and a reinforcing phase with a mass ratio of 100:0.5-1.5, and the base alloy is composed of the following components by weight percentage:

[0007] V 1.5%-2.0%, Al 3.6%-4.0%, Cr 1.0%-1.8%, Zr 1.5%-2.5%, Si 0.5%-1.0%, Sn 0.5%-1.2%, Mo 1.2%-2.0%, C≤0.1%, B 0.04%-0.2%, Sm 0.02%-0.05%, Nb 0.1%-0.15%, Er 0.04%-0.18%, and the balance is Ti and unavoidable impurities; the reinforcing phase is zirconium oxide.

[0008] As a further technical scheme, the weight ratio of B and Er to the weight ratio of Mo is 1-3:15.

[0009] As a further technical scheme, the weight ratio of B and Er is 1:1.

[0010] In the present application, by reasonably optimizing the content ratio among B, Er and Mo, when the weight ratio of B and Er to Mo is 1-3:15, and the weight ratio of B and Er is 1:1, the high-temperature resistance of the titanium alloy material for heat-resistant titanium welded pipe can be further improved. According to the calculation of high-temperature tensile strength retention rate = 700℃ tensile strength / room temperature tensile strength*100%, the 700℃ tensile strength retention rate is above 81%, and when the weight ratio of B and Er to Mo is outside the range of 1-3:15, the 700℃ tensile strength retention rate is slightly lower.

[0011] As a further technical solution, the zirconium oxide is boride composite zirconium oxide, and the raw materials of the boride composite zirconium oxide include boride and zirconium oxide in a weight ratio of 1-3:50.

[0012] As a further technical solution, the boride includes one or both of titanium diboride and molybdenum boride.

[0013] In the present application, the boride includes one or both of titanium diboride and molybdenum boride, and the boride is used for composite treatment of zirconium oxide, which can effectively improve the bonding strength of the zirconium oxide reinforcing phase and the matrix alloy, thereby more effectively pinning the grain boundary, inhibiting grain growth, making the microstructure of the titanium alloy material for heat-resistant titanium welded pipe more stable, and further improving the high-temperature resistance of the titanium alloy material for heat-resistant titanium welded pipe, so that the 700℃ tensile strength retention rate is above 85%.

[0014] As a further technical solution, the average particle size of the zirconium oxide is 5-20μm, for example, it can be 5μm, 10μm, 15μm, 20μm, and preferably 10μm.

[0015] As a further technical solution, the average particle size of the boride is 30-50nm, for example, it can be 30nm, 35nm, 40nm, 45nm, 50nm, and preferably 50nm.

[0016] As a further technical solution, the preparation method of the boride composite zirconium oxide includes the following steps: blending the zirconium oxide and the boride, ball milling to obtain the boride composite zirconium oxide.

[0017] As a further technical solution, during the ball milling, the ball milling speed is 100-200rpm, for example, it can be 100rpm, 120rpm, 150rpm, 180rpm, 200rpm, and preferably 150rpm, and the ball milling time is 20-30min, for example, it can be 20min, 25min, 30min, and preferably 25min.

[0018] As a further technical solution, the preparation method of the titanium alloy material for heat-resistant titanium welded pipe includes the following steps:

[0019] S1, according to the component of the base alloy, smelting, adding the reinforced phase blending, casting, obtaining the titanium alloy casting blank;

[0020] S2, the titanium alloy casting blank is forged, and the titanium alloy bar is obtained;

[0021] S3, the titanium alloy bar is heat treated, and the titanium alloy material for the heat-resistant titanium welded pipe is obtained.

[0022] As a further technical scheme, before smelting, the components of the base alloy are uniformly mixed, the electrode is pressed, and the vacuum welding of the electrode is carried out.

[0023] As a further technical scheme, when smelting, the vacuum consumable arc furnace is used for smelting.

[0024] When smelting, the temperature is 1680-1700 DEG C, for example, it can be 1680 DEG C, 1690 DEG C, 1700 DEG C, preferably 1690 DEG C, more preferably 1630 DEG C, and the time is 20-30 min, for example, it can be 20 min, 25 min, 30 min.

[0025] As a further technical scheme, when forging, first, at 1050-1100 DEG C, for example, it can be 1050 DEG C, 1060 DEG C, 1070 DEG C, 1080 DEG C, 1090 DEG C, 1100 DEG C, preferably 1050 DEG C, 1080 DEG C, 1100 DEG C, more preferably 1080 DEG C, forging 30-40 min, for example, it can be 30 min, 35 min, 40 min, then at 950-970 DEG C, for example, it can be 950 DEG C, 960 DEG C, 970 DEG C, forging 10-20 min, for example, it can be 10 min, 15 min, 20 min.

[0026] As a further technical scheme, when heat treating, it is divided into first-stage heat treatment and second-stage heat treatment.

[0027] When the first-stage heat treatment, the temperature is raised to 650-680 DEG C at a heating rate of 30-40 DEG C / min, and the temperature is kept for 2-3 h, and then the temperature is cooled to room temperature at a cooling rate of 30-40 DEG C / min.

[0028] When the second-stage heat treatment, the temperature is raised to 930-960 DEG C at a heating rate of 40-50 DEG C / min, and the temperature is kept for 20-40 min, and then the temperature is cooled to 600-650 DEG C at a cooling rate of 15-25 DEG C / min, and the temperature is kept for 2-3 h, and then the temperature is cooled to room temperature in the furnace.

[0029] The working principle and beneficial effects of the application are as follows:

[0030] In the present application, the titanium alloy material for heat-resistant titanium welded pipe comprises a base alloy and a reinforcing phase, the base alloy takes Ti element as a base element, combines V, Al, Cr, Zr, Si, Sn, Mo, C, B, Sm, Nb, Er elements, and meanwhile under the action of the zirconia reinforcing phase, the titanium alloy material for heat-resistant titanium welded pipe with uniform and stable internal structure can be obtained, and the titanium alloy material has good high-temperature resistance. Among them, by using Mo, B and Er together and optimizing the content of the three, the titanium alloy grain can be refined while the grain growth is effectively inhibited, so that the uniformity of the titanium alloy material is improved, thereby the titanium alloy material for heat-resistant titanium welded pipe has good high-temperature resistance, and the 700 DEG C tensile strength retention rate can be above 79% compared with the room temperature tensile strength. In addition, the reinforcing phase is zirconia, by introducing zirconia, the pinning effect can be achieved at the grain boundary, which can hinder the grain growth of the titanium alloy material at high temperature, so that the uniformity of the titanium alloy material is further improved. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also fall within the scope of protection of the present application.

[0032] In the following examples and comparative examples, the average particle size of zirconia is 10 μm, the average particle size of titanium diboride is 50 nm, and the average particle size of molybdenum boride is 50 nm; Ti, V, Al, Cr, Zr, Si, Sn, Mo, B, Sm, Nb and Er in the base alloy are added in the form of alloy.

[0033] Example 1

[0034] A titanium alloy material for heat-resistant titanium welded pipe comprises a base alloy and a reinforcing phase in a mass ratio of 100:0.5, and the base alloy is composed of the following components by weight percentage:

[0035] V 1.5%, Al 3.6%, Cr 1.0%, Zr 1.5%, Si 0.5%, Sn 0.5%, Mo 1.2%, C 0.02%, B 0.04%, Sm 0.02%, Nb 0.1%, Er 0.04%, and the balance is Ti and inevitable impurities; the reinforcing phase is zirconia;

[0036] The preparation method of the titanium alloy material for heat-resistant titanium welded pipe comprises the following steps:

[0037] S1, according to the component of the base alloy, after mixing uniformly, pressing the electrode, carrying out the vacuum welding of the electrode, then adopting the vacuum consumable arc furnace to smelt for 30 min at 1680 DEG C, adding zirconium oxide blending, casting, obtaining the titanium alloy casting blank;

[0038] S2, the titanium alloy casting blank is forged at 1050 DEG C for 40 min first, then forged at 950 DEG C for 20 min, obtaining the titanium alloy slab;

[0039] S3, the titanium alloy slab is heated to 650 DEG C at the heating rate of 30 DEG C / min, after keeping for 3 h, cooled to room temperature at the cooling rate of 30 DEG C / min, then heated to 930 DEG C at the heating rate of 40 DEG C / min, after keeping for 40 min, cooled to 600 DEG C at the cooling rate of 15 DEG C / min, keeping for 3 h, cooling to room temperature with the furnace, obtaining the titanium alloy material for heat-resistant titanium welded pipe.

[0040] Example 2

[0041] A titanium alloy material for heat-resistant titanium welded pipe, comprising base alloy and reinforcing phase with the mass ratio of 100:1, the base alloy is composed of the following components with the weight percentage:

[0042] V 1.8%, Al 3.8%, Cr 1.5%, Zr 2.0%, Si 0.8%, Sn 1.0%, Mo 1.5%, C 0.05%, B 0.04%, Sm 0.04%, Nb 0.13%, Er 0.04%, the balance is Ti and inevitable impurities; the reinforcing phase is zirconium oxide;

[0043] The preparation method of the titanium alloy material for heat-resistant titanium welded pipe comprises the following steps:

[0044] S1, according to the component of the base alloy, after mixing uniformly, pressing the electrode, carrying out the vacuum welding of the electrode, then adopting the vacuum consumable arc furnace to smelt for 25 min at 1690 DEG C, adding zirconium oxide blending, casting, obtaining the titanium alloy casting blank;

[0045] S2, the titanium alloy casting blank is forged at 1080 DEG C for 35 min first, then forged at 960 DEG C for 15 min, obtaining the titanium alloy slab;

[0046] S3, the titanium alloy slab is heated to 670 DEG C at the heating rate of 35 DEG C / min, after keeping for 2.5 h, cooled to room temperature at the cooling rate of 35 DEG C / min, then heated to 940 DEG C at the heating rate of 45 DEG C / min, after keeping for 30 min, cooled to 630 DEG C at the cooling rate of 20 DEG C / min, keeping for 2.5 h, cooling to room temperature with the furnace, obtaining the titanium alloy material for heat-resistant titanium welded pipe.

[0047] Embodiment 3

[0048] A titanium alloy material for heat-resistant titanium welded pipes comprises a base alloy and a reinforcing phase in a mass ratio of 100:1.5, the base alloy is composed of the following components in percentage by weight:

[0049] V 2.0%, Al 4.0%, Cr 1.8%, Zr 2.5%, Si 1.0%, Sn 1.2%, Mo 2.0%, C 0.1%, B 0.2%, Sm 0.05%, Nb 0.15%, Er 0.18%, and the balance being Ti and inevitable impurities; and the reinforcing phase is zirconium oxide;

[0050] A preparation method of the titanium alloy material for heat-resistant titanium welded pipes comprises the following steps:

[0051] S1, ingredients of the base alloy are allocated, mixed uniformly, and then pressed into an electrode, vacuum welding of the electrode is performed, and then a vacuum consumable arc furnace is used to smelt at 1700 DEG C for 20 min, zirconium oxide is added for blending, and then cast to obtain a titanium alloy cast blank;

[0052] S2, the titanium alloy cast blank is first forged at 1100 DEG C for 30 min, and then forged at 970 DEG C for 10 min to obtain a titanium alloy slab;

[0053] S3, the titanium alloy slab is heated to 680 DEG C at a heating rate of 40 DEG C / min, and then cooled to room temperature at a cooling rate of 40 DEG C / min, and then heated to 960 DEG C at a heating rate of 50 DEG C / min, and then cooled to 650 DEG C at a cooling rate of 25 DEG C / min, and then cooled to room temperature in the furnace after being kept at 650 DEG C for 2 h to obtain the titanium alloy material for heat-resistant titanium welded pipes.

[0054] Embodiment 4

[0055] The difference between the embodiment and embodiment 2 is that in the embodiment, the weight percentage of B added is 0.18%, and the weight percentage of Er added is 0.18%.

[0056] Embodiment 5

[0057] The difference between the embodiment and embodiment 2 is that in the embodiment, the weight percentage of B added is 0.05%, and the weight percentage of Er added is 0.05%.

[0058] Embodiment 6

[0059] The difference between the embodiment and embodiment 2 is that in the embodiment, the weight percentage of B added is 0.15%, and the weight percentage of Er added is 0.15%.

[0060] Embodiment 7

[0061] The difference between this example and Example 6 is that in this example, the reinforcing phase is boride composite zirconia, and the preparation method of the boride composite zirconia comprises the following steps: blending 50 parts of zirconia and 0.5 parts of molybdenum boride, and ball milling at 150 rpm for 25 min to obtain the boride composite zirconia.

[0062] Example 8

[0063] The difference between this example and Example 6 is that in this example, the reinforcing phase is boride composite zirconia, and the preparation method of the boride composite zirconia comprises the following steps: blending 50 parts of zirconia and 0.5 parts of titanium diboride, and ball milling at 150 rpm for 25 min to obtain the boride composite zirconia.

[0064] Example 9

[0065] The difference between this example and Example 6 is that in this example, the reinforcing phase is boride composite zirconia, and the preparation method of the boride composite zirconia comprises the following steps: blending 50 parts of zirconia and 4 parts of titanium diboride, and ball milling at 150 rpm for 25 min to obtain the boride composite zirconia.

[0066] Example 10

[0067] The difference between this example and Example 6 is that in this example, the reinforcing phase is boride composite zirconia, and the preparation method of the boride composite zirconia comprises the following steps: blending 50 parts of zirconia and 1 part of titanium diboride, and ball milling at 150 rpm for 25 min to obtain the boride composite zirconia.

[0068] Example 11

[0069] The difference between this example and Example 6 is that in this example, the reinforcing phase is boride composite zirconia, and the preparation method of the boride composite zirconia comprises the following steps: blending 50 parts of zirconia and 3 parts of titanium diboride, and ball milling at 150 rpm for 25 min to obtain the boride composite zirconia.

[0070] Comparative Example 1

[0071] The difference between this example and Example 2 is that in this example, the weight percentage of Er added is 0.08%, and no B is added.

[0072] Comparative Example 2

[0073] The difference between this example and Example 2 is that in this example, the weight percentage of B added is 0.08%, and no Er is added.

[0074] Comparative Example 3

[0075] The difference between the present comparative example and Example 2 is that in the present comparative example, neither Er nor B is added, and the weight percentage of Mo added is 1.58%.

[0076] Comparative Example 4

[0077] The difference between the present comparative example and Example 2 is that in the present comparative example, neither Er nor B is added, and the weight percentage of Mo added is 1.58%.

[0078] Comparative Example 5

[0079] The difference between the present comparative example and Example 2 is that in the present comparative example, neither Er nor B is added, and the weight percentage of Mo added is 1.58%.

[0080] Comparative Example 6

[0081] The difference between the present comparative example and Example 2 is that in the present comparative example, neither Er nor B is added, and the weight percentage of Mo added is 1.58%.

[0082] Experimental Example

[0083] The heat-resistant titanium alloy material samples prepared from Examples 1-11 and Comparative Examples 1-6 were tested for room temperature tensile strength according to the method in GB / T 228.1-2021 “Metallic Materials-Tensile Testing-Part 1: Method of Room Temperature Test”, and for 700℃ tensile strength according to the method in GB / T 228.2-2015 “Metallic Materials-Tensile Testing-Part 2: Method of High Temperature Test”, and the test results are shown in Table 1.

[0084] The test results are shown in Table 1:

[0085] Table 1 Performance test results of Examples 1-11 and Comparative Examples 1-6

[0086]

[0087] According to the calculation of high temperature tensile strength retention rate = 700℃ tensile strength / room temperature tensile strength x 100%, compared with Comparative Examples 1-6, the high temperature tensile strength retention rate of the heat-resistant titanium alloy material prepared from Examples 1-11 is improved, and the 700℃ tensile strength retention rate is above 79%, indicating that in the heat-resistant titanium alloy material, Mo, B and Er are simultaneously added to the base alloy, and the zirconia reinforcing phase is combined, which can effectively improve the high temperature resistance of the heat-resistant titanium alloy material for titanium welded pipes.

[0088] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A titanium alloy material for a heat-resistant titanium welded pipe, characterized by comprising, in mass %, The alloy material for heat-resistant titanium welded pipe comprises a base alloy and a reinforcing phase, wherein the base alloy is composed of the following components in percentage by weight: V 1.5%~2.0%, Al 3.6%~4.0%, Cr 1.0%~1.8%, Zr 1.5%~2.5%, Si 0.5%~1.0%, Sn 0.5%~1.2%, Mo 1.2%~2.0%, C≤0.1%, B 0.04%~0.2%, Sm 0.02%~0.05%, Nb 0.1%~0.15%, Er 0.04%~0.18%, and the balance being Ti and inevitable impurities; and the reinforcing phase is zirconium oxide.

2. The titanium alloy material for a heat-resistant titanium welded tube according to claim 1, characterized by The weight ratio of B and Er to Mo is 1~3:

15.

3. The titanium alloy material for a heat-resistant titanium welded tube according to claim 1, characterized by The zirconium oxide is boride composite zirconium oxide, and raw materials of the boride composite zirconium oxide comprise boride and zirconium oxide in a weight ratio of 1~3:

50. The boride comprises one or both of titanium diboride and molybdenum boride. The preparation method of the boride composite zirconium oxide comprises the following steps: blending the zirconium oxide and the boride, and ball milling to obtain the boride composite zirconium oxide.

4. The titanium alloy material for a heat-resistant titanium welded tube according to claim 1, characterized by The preparation method of the alloy material for heat-resistant titanium welded pipe comprises the following steps: S1, according to the component of the base alloy, the alloy material is prepared by alloying, melting, adding the reinforcing phase, blending, and casting to obtain a titanium alloy cast blank; S2, the titanium alloy cast blank is forged to obtain a titanium alloy slab; S3, the titanium alloy slab is heat treated to obtain the alloy material for heat-resistant titanium welded pipe.

5. The titanium alloy material for a heat-resistant titanium welded tube according to claim 4, characterized by Before melting, the components of the base alloy are mixed uniformly, an electrode is pressed, and vacuum welding of the electrode is performed.

6. The titanium alloy material for a heat-resistant titanium welded tube according to claim 4, characterized by During melting, a vacuum consumable arc furnace is used for melting; During melting, the temperature is 1680~1700℃, and the time is 20~30min.

7. The titanium alloy material for a heat-resistant titanium welded tube according to claim 4, characterized by During forging, first, forging is performed at 1050~1100℃ for 30~40min, and then forging is performed at 950~970℃ for 10~20min.

8. The titanium alloy material for a heat-resistant titanium welded tube according to claim 4, characterized by During heat treatment, the heat treatment is divided into first-stage heat treatment and second-stage heat treatment; During the first-stage heat treatment, the temperature is raised to 650~680℃ at a temperature raising rate of 30~40℃ / min, and then the temperature is kept for 2~3h, and then the temperature is cooled to room temperature at a temperature lowering rate of 30~40℃ / min; During the second-stage heat treatment, the temperature is raised to 930~960℃ at a temperature raising rate of 40~50℃ / min, and then the temperature is kept for 20~40min, and then the temperature is cooled to 600~650℃ at a temperature lowering rate of 15~25℃ / min, and then the temperature is kept for 2~3h, and then the temperature is cooled to room temperature in the furnace.

Images