Titanium-copper alloy pipe and method for manufacturing the same

Abstract

The application discloses a titanium-copper alloy pipe and a preparation method thereof. The titanium-copper alloy pipe comprises the following components in mass percent: Ti: 2.3-3.4%, Cr: 0.02-0.2%, Ni: 0.02-0.5%, Al: 0.15-0.20%, rare earth elements: 0-0.05%, the rare earth elements being at least one of Ce, La, Sc and Y, the balance being Cu and inevitable impurities, and Cu+Ti≥96.0%. The preparation method comprises the following steps: titanium-copper ingot casting, homogenization heat treatment, hole drilling and breaking down, pickling, quenching, rolling, aging hardening treatment, nondestructive testing, water pressure detection, wall thickness measurement and the like. The titanium-copper alloy pipe has a tensile strength of 1100-1250 MPa, a yield strength of 1050-1100 MPa, an elongation after fracture of ≥7.0%, and a hardness HRC of 38-42, and meets the requirements of the strength and corrosion resistance of a pressure-resistant outer cylinder for a logging-while-drilling device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the non-ferrous alloy material processing industry, and relates to an alloy pipe and a manufacturing method thereof, in particular to a high-strength titanium-copper alloy pipe material for a pressure-resistant outer cylinder of a logging-while-drilling device and a preparation method thereof. BACKGROUND

[0002] In the logging-while-drilling industry, due to the complex and changeable geological environment, the environment is very harsh, and during the use of drilling equipment and logging equipment, the external magma is mixed with high chlorine, carbon dioxide, hydrogen and acid and the like. Therefore, a material with high strength, corrosion resistance, non-magnetic, wear resistance, fatigue resistance and the like is needed as the main body or key part of the drilling equipment to meet these complex environmental requirements.

[0003] The beryllium copper alloy has good comprehensive performance, the alloy has high hardness, strength, elastic limit and fatigue limit, and has strong corrosion resistance, electrical conductivity and non-magnetic property, so that it has a long service life in a harsh environment of low temperature, high temperature, high pressure and acid. Therefore, it is widely used in manufacturing industries in various high-tech fields, and is particularly suitable for oil and coal drilling equipment, so that the logging instrument can meet the application requirements in the harsh downhole environment. However, beryllium in beryllium bronze is toxic, beryllium is volatile, which is a strong carcinogenic element, and has great harm to human health, so the safety problem in the production and use of beryllium bronze cannot be ignored; and the beryllium bronze is expensive, has poor stress relaxation resistance, and has large deformation after aging. SUMMARY

[0004] The present application provides a high-strength and corrosion-resistant titanium-copper alloy pipe material for logging-while-drilling equipment, which has a tensile strength of ≥1100MPa, a yield strength of ≥1050MPa, an elongation after fracture of ≥7.0%, and a hardness of HRC 38-42.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A titanium-copper alloy pipe material, the chemical composition of the titanium-copper alloy pipe material is as follows: Ti: 2.3-3.4%, Cr: 0.02-0.2%, Ni: 0.02-0.5%, Al: 0.15-0.20%, rare earth elements 0-0.05%, the rare earth elements being at least one of Ce, La, Sc and Y; the balance being Cu and unavoidable impurities, and Cu+Ti≥96.0%.

[0007] Trace elements: the addition of trace amounts of Ce, La, Sc and Y can refine the grains as the crystallization core and play a solid solution strengthening role, further improving the strength of the alloy.

[0008] The present application further provides a preparation method of the titanium-copper alloy pipe material, comprising the following preparation steps:

[0009] (1) Melting: raw materials are added into a vacuum melting furnace for melting, and the melting temperature is 1250-1300°C; a covering agent and a solvent are added during the melting process, the covering agent is a mixture of charcoal, carbon powder and borax, the amount of the covering agent is 0.5-0.7% of the mass of the raw materials, and the solvent is cryolite; the covering agent is roasted before being added, the roasting temperature is ≥200°C, and the roasting time is ≥1h; a stirring rod made of graphite is used for stirring after melting.

[0010] (2) Pouring: the above-mentioned metal liquid is poured in a vacuum furnace, and after being cooled to room temperature, the ingot is taken out of the vacuum melting furnace; the ingot is sawed at the head and tail, and the head is cut off by 100-150mm, and the tail is cut off by 150-200mm.

[0011] (3) Homogenization treatment: the ingot is put into a vacuum furnace, nitrogen is filled, and heated to 750-820°C at a heating rate of 10°C / min, and after being kept for 2h, it is naturally cooled to room temperature, so that the internal structure of the ingot is homogenized.

[0012] (4) Drilling: the surface of the ingot is mechanically processed, the surface of the ingot is turned into a regular cylindrical shape, both ends are turned flat, then a through hole is drilled in the center of the ingot, and then the hole is extruded to open.

[0013] (5) Pickling: the pipe blank after being drilled is immersed in an acid solution for 2-4 times of pickling, and then washed with clean water to obtain a pickled titanium-copper pipe blank; the acid solution is a mixture of 98% sulfuric acid, 65% nitric acid and water, and the volume ratio of the 98% sulfuric acid, the 65% nitric acid and water in the acid solution is 1:1:3.

[0014] (6) Quenching: the pickled pipe blank is heated to 750-850°C, kept for 2h, and then put into a water tank for quenching heat treatment, and the water temperature in the water tank is kept at 30-50°C.

[0015] (7) Rolling: the above-mentioned pipe blank is cold-rolled to the required size of the product; a four-roll rolling mill is used for cold rolling of the blank; 2-3 passes are used for rolling, and the processing rate of each pass is 32-64%.

[0016] (8) Aging hardening treatment: the titanium-copper pipe material is kept at 400-500°C for 2-8h, and aged in a hydrogen atmosphere, and the pressure of the hydrogen is 0.2-0.4MPa; after the aging treatment, it is air-cooled to room temperature.

[0017] (9) Product inspection: the product pipe material is subjected to non-destructive testing, water pressure testing and wall thickness measurement, and the qualified product pipe material is the final product.

[0018] The titanium-copper alloy pipe material produced by the above-mentioned method has the following advantages:

[0019] 1. By homogenizing heat treatment and drilling, cogging and other processes on the ingot, cold rolling to the required size of the product, the yield and material utilization are greatly improved;

[0020] 2. The titanium copper pipe finally obtained has a tensile strength of 1100-1250 MPa, a yield strength of 1050-1100 MPa, an elongation after fracture of ≥7.0%, and a hardness HRC of 38-42, which are higher than the technical indexes of the prior art, and meet the requirements of the strength and corrosion resistance of the pressure-resistant outer cylinder of the logging equipment.

[0021] The titanium copper alloy pipe prepared by the method has high strength, hardness and elasticity, excellent wear resistance, fatigue resistance, corrosion resistance, weldability and machinability, and the mechanical and physical properties thereof are comparable to those of beryllium copper alloy. Compared with beryllium copper alloy, the titanium copper alloy pipe is non-toxic and does not harm human health during use, so it is very meaningful to replace the toxic beryllium copper alloy with the titanium copper alloy pipe for the logging equipment. DETAILED DESCRIPTION

[0022] The application will be further described in detail in the specific embodiments.

[0023] Example 1

[0024] A preparation method of a titanium copper alloy pipe, the preparation method comprising the following steps:

[0025] (1) batching: weighing raw materials, the raw materials containing chemical components and their weight percentages being: Ti 2.3%, Cr 0.10%, Ni 0.15%, Al 0.14%, Ce 0.02%, and the balance being copper and unavoidable impurities;

[0026] (2) vacuum melting: placing the raw materials weighed in step (1) into a vacuum melting device for vacuum melting, the vacuum degree being 10 Pa, the temperature being 1250°C, and the temperature being maintained for 25 min, to form a titanium copper alloy melt;

[0027] (3) casting: casting the titanium copper alloy melt obtained in step (2) into an ingot and rapidly water cooling to room temperature to achieve the purpose of solid solution treatment; cutting off 150 mm from the head of the ingot and cutting off 200 mm from the tail of the ingot;

[0028] (4) homogenization treatment: placing the ingot obtained in step (3) into a vacuum furnace, filling nitrogen gas, heating to 750°C at a heating rate of 10°C / min, maintaining for 2 hours, and then naturally cooling to room temperature;

[0029] (5) Drilling and pickling: the ingot obtained in step (4) is drilled through the center and then extruded into a pipe blank, the drilled pipe blank is immersed in acid solution for pickling twice, and then washed with clean water to obtain a pickled titanium copper pipe blank;

[0030] (6) Quenching: the pipe blank after pickling in step (5) is heated to 750℃ and held for 2 hours, and then quenched by placing it in a water tank for heat treatment;

[0031] (7) Rolling: the pipe blank is cold-rolled to the required size of the product, and the rolling is carried out in 2-3 passes, and the processing rate of each pass is 32-64%.

[0032] (8) Aging treatment: the pipe obtained in step (7) is aged at a temperature of 400℃ for 4 hours, and then air-cooled to room temperature to obtain the titanium copper alloy pipe.

[0033] The performance test results are shown in Table 1.

[0034] Example 2

[0035] A method for preparing a titanium copper alloy pipe, the method comprising the following steps:

[0036] (1) batching: weighing raw materials, the chemical components contained in the raw materials and their weight percentages are: Ti 2.6%, Cr 0.10%, Ni 0.15%, Al 0.16%, Ce 0.02%, and the balance is copper and unavoidable impurities;

[0037] (2) vacuum melting: the raw materials weighed in step (1) are placed in a vacuum melting device for vacuum melting, the vacuum degree is 10 Pa, and the temperature is 1250℃, and the temperature is maintained for 25 min to form a titanium copper alloy melt;

[0038] (3) casting: the titanium copper alloy melt obtained in step (2) is cast into an ingot and rapidly water-cooled to room temperature to achieve the purpose of solid solution treatment; the head of the ingot is cut off by 150 mm, and the tail is cut off by 200 mm;

[0039] (4) homogenization treatment: the ingot obtained in step (3) is placed in a vacuum furnace, nitrogen is filled, heated to 770℃ at a rate of 10℃ / min, and then naturally cooled to room temperature after holding for 2 hours;

[0040] (5) drilling and pickling: the ingot obtained in step (4) is drilled through the center and then extruded into a pipe blank, the drilled pipe blank is immersed in acid solution for pickling twice, and then washed with clean water to obtain a pickled titanium copper pipe blank;

[0041] (6) Quenching: the pipe blank after pickling in step (5) is heated to 780℃ and held for 2 hours, and then quenched by placing it in a water tank for heat treatment;

[0042] (7) Rolling: the pipe blank is cold-rolled to the required size of the product, and 2-3 passes are rolled, and the processing rate of each pass is 32-64%.

[0043] (8) Aging treatment: the pipe obtained in step (7) is aged at a temperature of 420°C for 4 hours, and after the aging treatment is completed, it is air-cooled to room temperature to obtain the titanium-copper alloy pipe.

[0044] The performance test results are shown in Table 1.

[0045] Example 3

[0046] A preparation method of a titanium-copper alloy pipe, the preparation method comprising the following steps:

[0047] (1) batching: weighing raw materials, the chemical components contained in the raw materials and their weight percentages being: Ti 3.0%, Cr 0.10%, Ni: 0.15%, Al 0.18%, Ce 0.02%, La 0.02%, and the balance being copper and unavoidable impurities;

[0048] (2) vacuum melting: the raw materials weighed in step (1) are placed into a vacuum melting device for vacuum melting, the vacuum degree being 10 Pa, and the temperature being 1250°C, and the temperature is maintained for 30 min to form a titanium-copper alloy melt;

[0049] (3) casting: the titanium-copper alloy melt obtained in step (2) is cast into an ingot, and is rapidly water-cooled to room temperature to achieve the purpose of solid solution treatment; the head of the ingot is cut off by 150 mm, and the tail is cut off by 200 mm;

[0050] (4) homogenization treatment: the ingot obtained in step (3) is placed into a vacuum furnace, nitrogen is filled, and heating is performed to 770°C at a heating rate of 10°C / min, and after being maintained for 2 hours, it is naturally cooled to room temperature;

[0051] (5) drilling and pickling: then the center of the ingot obtained in step (4) is drilled through, and then extruded to break down, the pipe blank after being drilled is immersed in acid solution for pickling 2 times, and then washed clean with clean water to obtain a titanium-copper pipe blank after pickling;

[0052] (6) quenching: the pipe blank after pickling in step (5) is heated to 780°C and maintained for 2 hours, and then placed into a water tank for quenching heat treatment;

[0053] (7) rolling: the pipe blank is cold-rolled to the required size of the product, and 2-3 passes are rolled, and the processing rate of each pass is 32-64%.

[0054] (8) aging treatment: aging treatment of the pipe material obtained in step (7) at a temperature of 420℃ for 8 hours to obtain the titanium copper alloy pipe material.

[0055] The performance test results are shown in Table 1.

[0056] Example 4

[0057] A preparation method of a titanium copper alloy pipe material, the preparation method comprising the following steps:

[0058] (1) batching: weighing raw materials, the chemical components contained in the raw materials and the weight percentage thereof being: Ti 3.4%, Cr 0.10%, Ni: 0.10%, Al 0.20%, Ce 0.02%, La 0.02%, the balance being copper and unavoidable impurities;

[0059] (2) vacuum melting: placing the raw materials weighed in step (1) into a vacuum melting device for vacuum melting, the vacuum degree being 10 Pa, the temperature being 1300℃, and the temperature being maintained for 20 min to form a titanium copper alloy melt;

[0060] (3) casting: casting the titanium copper alloy melt obtained in step (2) into an ingot and rapidly water cooling to room temperature to achieve the purpose of solid solution treatment; cutting off 150mm from the head of the ingot and cutting off 200mm from the tail of the ingot;

[0061] (4) homogenization treatment: placing the ingot obtained in step (3) into a vacuum furnace, filling nitrogen gas, heating to 770℃ at a heating rate of 10℃ / min, maintaining for 2 hours and then naturally cooling to room temperature;

[0062] (5) drilling and pickling: then drilling a through hole in the center of the ingot obtained in step (4), extruding the open hole, immersing the open hole in acid solution for pickling 2 times, and then rinsing with clean water to obtain a titanium copper pipe blank after pickling;

[0063] (6) quenching: heating the pipe blank after pickling in step (5) to 780℃, maintaining for 2 hours, and then placing it into a water tank for quenching heat treatment;

[0064] (7) rolling: cold rolling the above pipe blank to the required size of the product, rolling 2-3 passes, and the processing rate of each pass being 32-64%;

[0065] (8) aging treatment: aging treatment of the pipe material obtained in step (7) at a temperature of 420℃ for 8 hours to obtain the titanium copper alloy pipe material.

[0066] The performance test results are shown in Table 1.

[0067] Example 5

[0068] A preparation method of a titanium-copper alloy pipe, the preparation method comprising the following steps:

[0069] (1) batching: weighing raw materials, the raw materials containing chemical components and their weight percentages as follows: Ti 3.4%, Cr 0.10%, Ni: 0.10%, Al 0.20%, Ce 0.02%, La 0.02%, Sc 0.01%, Y 0.01%, and the balance being copper and inevitable impurities;

[0070] (2) vacuum smelting: placing the raw materials weighed in step (1) into a vacuum smelting device for vacuum smelting, the vacuum degree being 10 Pa, and the temperature being 1300 ℃, and keeping the temperature for 20 min to form a titanium-copper alloy melt;

[0071] (3) casting: casting the titanium-copper alloy melt obtained in step (2) into an ingot and rapidly water cooling to room temperature to achieve the purpose of solid solution treatment; cutting off 150 mm from the head of the ingot and cutting off 200 mm from the tail of the ingot;

[0072] (4) homogenization treatment: placing the ingot obtained in step (3) into a vacuum furnace, filling nitrogen gas, heating to 820 ℃ at a heating rate of 10 ℃ / min, keeping the temperature for 2 hours, and then naturally cooling to room temperature;

[0073] (5) drilling and pickling: then drilling a through hole in the center of the ingot obtained in step (4), extruding the hole to form a pipe blank, immersing the pipe blank after the hole into acid solution for pickling twice, and then rinsing with clean water to obtain a titanium-copper pipe blank after pickling;

[0074] (6) quenching: heating the pipe blank after pickling in step (5) to 780 ℃, keeping the temperature for 2 hours, and then placing into a water tank for quenching heat treatment;

[0075] (7) rolling: cold rolling the pipe blank to the required size of the product, and rolling for 2-3 passes, and the processing rate of each pass being 32-64%;

[0076] (8) aging treatment: aging treating the pipe material obtained in step (7) at a temperature of 500 ℃ for 8 hours to obtain the titanium-copper alloy pipe.

[0077] The performance test results are shown in Table 1.

[0078] Table 1: Performance test results of titanium-copper alloy pipes of Examples 1-5

[0079] Item Tensile strength / MPa Yield strength / MPa Elongation at break / % Hardness HRC Example 1 1103 1054 9.8 38.1 Example 2 1112 1070 9.7 38.8 Example 3 1158 1096 8.5 39.3 Example 4 1209 1150 7.6 40.2 Example 5 1232 1163 7.3 41.0

[0080] The upper and lower limits and interval values of the process parameters (such as temperature, time, etc.) of the present application can all achieve the method, and examples are not listed here.

[0081] The details of the present application not described in detail can adopt the conventional technical knowledge in the art.

[0082] Finally, it should be noted that the above examples are intended to illustrate the technical solutions of the present application and not to limit. Although the present application is described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application are modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method for producing a titanium-copper alloy pipe, characterized by comprising: The titanium-copper alloy pipe has the following chemical composition by mass percentage: Ti: 2.3-3.4%, Cr: 0.02-0.2%, Ni: 0.02-0.5%, Al: 0.15-0.20%, rare earth elements: 0.02-0.05%, the rare earth elements being at least one of Ce, La, Sc and Y, and the balance being Cu and inevitable impurities, with Cu+Ti≥96.0%. ​ The preparation method comprises the following preparation steps: 1) Melting: The raw materials are weighed according to the proportion, and then are added into a vacuum melting furnace for melting, with the melting temperature being 1250-1300℃; a covering agent and a solvent are added during the melting process; the covering agent is pre-baked before being added, with the baking temperature being ≥200℃ and the baking time being ≥1h; the molten metal liquid after melting is stirred using a stirring rod; 2) Pouring: The uniformly stirred metal liquid is poured in a vacuum furnace, and after being cooled to room temperature, the ingot is taken out from the vacuum melting furnace; the head and tail of the ingot are sawn off; 3) Homogenization treatment: The ingot is placed in a vacuum furnace, nitrogen is filled in, and then the ingot is heated to 750-820℃ at a heating rate of 10℃ / min, and after being kept warm, the ingot is naturally cooled to room temperature, so that the internal structure of the ingot is homogenized; 4) Drilling: The surface of the ingot is turned into a regular cylindrical shape, both ends are turned flat, then a through hole is drilled in the center of the ingot, and then the ingot is extruded to open the hole; 5) Pickling: The pipe blank after being opened is immersed in an acid liquid for pickling 2-4 times, and then is washed clean with clean water, so that the titanium-copper pipe blank after pickling is obtained; 6) Quenching: The titanium-copper pipe blank after pickling is heated to 750-850℃, and is kept warm for 1-3h, and then is subjected to quenching heat treatment, with the quenching temperature being kept at 30-50℃; 7) Rolling: The titanium-copper pipe blank is cold-rolled; the rolling is performed for 2-3 passes, and the processing rate of each pass is 32-64%; 8) Aging hardening treatment: The titanium-copper alloy pipe is kept warm at 400-500℃ for 2-8h, and is aged in a hydrogen atmosphere, with the hydrogen pressure being 0.2-0.4MPa; after the aging treatment, the titanium-copper alloy pipe is air-cooled to room temperature; 9) Product inspection: The titanium-copper alloy pipe is subjected to non-destructive testing, water pressure testing and wall thickness measurement, and the qualified product is the final product.

2. The production method according to claim 1, characterized by, The titanium-copper alloy pipe has a tensile strength≥1100MPa, a yield strength≥1050MPa, an elongation after fracture≥7.0%, and a hardness HRC 38-42.

3. The production method according to claim 1, characterized by, The covering agent is a mixture of charcoal, carbon powder and borax, and the amount of the covering agent is 0.5-0.7% of the mass of the raw materials; the solvent is ice crystal.

4. The method of claim 1, wherein, The stirring rod is made of graphite.

5. The preparation method according to claim 1, characterized in that, The sawing off of the head and tail of the ingot is as follows: the head is cut off by 100-150mm, and the tail is cut off by 150-200mm.

6. The method of claim 1, wherein, The acid liquid is a mixture of 98% sulfuric acid, 65% nitric acid and water, and the volume ratio of the 98% sulfuric acid, the 65% nitric acid and water in the acid liquid is 1:1:3.