Production process of titanium steel composite pipe

Abstract

The invention discloses a production process of a titanium-steel composite pipe. Pure titanium and carbon steel are prepared into a titanium-steel composite plate in an explosive cladding and heating rolling mode, the titanium-steel composite plate is cut after being subjected to acid pickling, the obtained titanium-steel composite plate is rolled into a pipe shape, the edge of the titanium-steel composite plate is subjected to double-groove composite groove design, and the grooves are subjected to multi-layer and multi-pass welding; and performing multi-pass cold drawing on the welded titanium-steel composite pipe, and degreasing, annealing, pickling and straightening the obtained cold-drawn titanium-steel composite pipe to obtain the titanium-steel composite pipe. According to the technology, the titanium-steel composite plate prepared through a mature technology is used as a raw material, the situation that the interface bonding quality is damaged due to the fact that a Fe-Ti phase is generated on an interface can be avoided, then the cold drawing technology is used for treating the titanium-steel composite plate, the performance uniformity and the interface strength of the titanium-steel composite pipe can be improved, the product quality is improved to a great extent, the product specifications are diversified, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of composite pipe preparation, and in particular relates to a production process of a titanium-steel composite pipe. Background Art

[0002] Titanium-steel composite pipes give full play to the excellent properties of both materials. They are not only high in strength, but also have good corrosion resistance, which can extend the service life of the pipe and reduce production costs. Therefore, titanium-steel composite pipes are widely used in the fields of petroleum, chemical industry, machinery and marine engineering.

[0003] The main preparation methods of titanium steel composite tubes include drawing composite method, hydraulic bulging composite method and hot rolling composite method. The drawing composite method is to deform the assembled titanium steel composite tube and the steel tube simultaneously under the restriction of the forming die, so as to achieve a close combination of the titanium tube and the steel tube interface; the drawing composite method has a simple process, high forming efficiency, and good roundness of the inner surface of the titanium steel composite tube, but it does not achieve sufficient plastic deformation during the forming process, and the bonding force is relatively small. The hydraulic bulging composite method assembles the steel tube and the titanium tube, then seals both ends, injects liquid into the inside of the titanium tube, and controls the pressure by controlling the hydraulic strength. As the pressure inside the tube continues to increase, the titanium tube changes from an elastic deformation state to a plastic deformation state, and the outer surface of the titanium tube contacts the inner surface of the steel tube. The steel tube undergoes elastic deformation under the action of the contact force, and the steel tube and the titanium tube are in close contact. When the pressure rises to a certain value, the outer surface of the steel tube is close to the mold. After unloading the internal pressure, the steel tube and the titanium tube fit tightly together. The hydraulic bulging composite method has a simple process and is easy to control, but the forming device has a complex structure, and the interface bonding strength of the prepared titanium-steel composite tube is weak. The hot rolling composite method is to plastically deform the titanium tube and the steel tube under high temperature and high pressure, and the element diffusion occurs at the interface to achieve metallurgical bonding. The interface bonding strength of the prepared titanium-steel composite tube is high, but the interface needs to be vacuum treated to prevent high-temperature oxidation of the interface, resulting in high production costs. Summary of the invention

[0004] In order to solve the problems of weak interface bonding strength and high production cost of titanium-steel composite pipes produced by prior art, the present invention uses titanium-steel composite plates prepared by mature technology as raw materials, which can avoid the generation of Fe-Ti phase at the interface to damage the interface bonding quality, and then uses a simple mechanical cold drawing process to process it, which can improve the performance uniformity and interface strength of the titanium-steel composite pipe, greatly improve product quality, diversify product specifications, reduce costs, and have good economic benefits.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a production process of a titanium-steel composite pipe, the production process comprising the following steps:

[0006] S1: pure titanium and carbon steel are prepared into titanium steel composite plates by explosive composite hot rolling, and then cut after pickling;

[0007] S2: rolling the titanium-steel composite plate obtained in step S1 into a tube, adopting a double-groove composite groove design for the edge of the titanium-steel composite plate, and after the groove processing is completed, performing multi-layer and multi-pass welding on the groove until it is built-up and flush with the base material;

[0008] S3: performing multiple cold drawing on the titanium steel composite pipe welded in step S2 to obtain a cold drawn titanium steel composite pipe;

[0009] S4: Degreasing, annealing, pickling and straightening the cold drawn titanium steel composite tube to obtain the titanium steel composite tube.

[0010] In the above technical solution, further, in step S1, the pure titanium is TA1, TA2, TA3, TA4, TA5, TA6, etc., and the carbon steel is Q235, Q345, X52, X60, X70, X80, etc.;

[0011] Furthermore, in step S1, the pickled titanium-steel composite plate is cut according to size requirements.

[0012] Further, in step S2, the composite plate adopts a 30° double-groove composite groove design, one side of the pure titanium layer is a V-shaped groove, the groove angle is 30° to 40°, and the depth is the thickness of the pure titanium layer; one side of the carbon steel layer is a V-shaped groove, the groove angle is 60° to 80°, and the depth is the thickness of the carbon steel layer;

[0013] Furthermore, in step S2, hydrochloric acid is used to clean the surface of the groove;

[0014] Furthermore, in step S2, during the welding process, the welding wire for the titanium layer is pure titanium welding wire ERTi-1, and the welding wire for the steel layer is carbon structural steel wire;

[0015] Further, in step S2, the welding speed of each layer is 100-180 mm / min, and the current is 90-150 A;

[0016] Furthermore, in step S2, argon gas is used throughout the entire welding process to fully protect the weld area and the surrounding area;

[0017] Furthermore, in step S2, laser detection is performed on the welding area to detect whether there are defects such as cracks, pores and lack of fusion in the welding area. If defects are present, the weld needs to be cut and re-welded.

[0018] Furthermore, in step S3, a cold drawing machine is used to perform multiple continuous cold drawing on the welded titanium-steel composite pipe, with 1 to 5 cold drawing passes each time, and the cold drawing rate of each pass is controlled at 5% to 20%. The maximum drawing force of the drawing machine is 350 to 450 T, and the drawing speed is 10 to 40 mm / min.

[0019] Further, in step S4, the degreasing is to use a hydrocarbon solution to clean the lubricating oil on the inner and outer surfaces of the pipe;

[0020] Further, in step S4, the annealing is to place one end of the titanium-steel composite tube in a heating chamber, start the electric heating furnace, raise the temperature in the heating chamber to 1150°C~1250°C, and keep it warm for 2~3 minutes, then move the titanium-steel composite tube at a speed of 30~90mm / min, move the other end of the titanium-steel composite tube to the heating chamber, stop moving, and maintain the temperature at 950°C~1050°C for homogenization treatment for 30~40 minutes.

[0021] Furthermore, in step S4, roller straightening is performed after pickling.

[0022] Furthermore, in steps S1 and S4, the pickling is performed using a mixture of hydrofluoric acid, nitric acid and water.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention aims at the defects of the prior art that the production process of titanium steel seamless pipe is complicated, the technical conditions are strict, and the manufacturing cost is high; at the same time, the interface bonding strength of titanium steel composite pipe directly compounded by mechanical method is relatively weak. In order to solve the problems of weak interface bonding strength and high production cost of titanium steel composite pipe produced by existing composite pipes, the present invention provides a production process method of titanium steel composite pipe, which uses titanium steel composite plate prepared by mature process as raw material, can avoid the generation of Fe-Ti phase at the interface to damage the interface bonding quality, and then uses the cold drawing process in a simple mechanical method to process it, which can improve the performance uniformity and interface strength of titanium steel composite pipe, greatly improve the product quality, diversify product specifications, reduce manufacturing costs, and have good economic benefits. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific examples, but the present invention is not limited in any way. To avoid redundant description, the raw materials in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified.

[0026] A production process for a titanium-steel composite pipe, the production process comprising the following steps:

[0027] S1: Pure titanium and carbon steel are prepared into titanium-steel composite plates by explosive composite hot rolling, and then cut after pickling.

[0028] S2: rolling the titanium-steel composite plate obtained in step S1 into a tube, adopting a double-groove composite groove design for the edge of the titanium-steel composite plate, and after the groove processing is completed, performing multi-layer and multi-pass welding on the groove until it is built-up and flush with the base material;

[0029] The composite plate adopts a 30° double-groove composite groove design. One side of the pure titanium layer is a V-shaped groove with a groove angle of 30°~40° and a depth equal to the thickness of the pure titanium layer; one side of the carbon steel layer is a V-shaped groove with a groove angle of 60°~80° and a depth equal to the thickness of the carbon steel layer.

[0030] The welding speed of each layer is 100-180 mm / min, and the current is 90-150 A. Argon gas is used to protect the weld area and nearby areas during the welding process.

[0031] S3: performing multiple cold drawing on the titanium steel composite pipe welded in step S2 to obtain a cold drawn titanium steel composite pipe;

[0032] Each cold drawing is performed for 1 to 5 passes, and the cold drawing rate of each pass is controlled at 5% to 20%. The maximum drawing force of the drawing machine is 350 to 450T, and the drawing speed is 10 to 40mm / min.

[0033] S4: Degreasing, annealing, pickling and straightening the cold drawn titanium steel composite tube to obtain a titanium steel composite tube;

[0034] The degreasing is to use hydrocarbon solution to clean the lubricating oil on the inner and outer surfaces of the pipe; the annealing is to place one end of the titanium-steel composite pipe in a heating chamber, start the electric heating furnace, raise the temperature in the heating chamber to 1150°C~1250°C, and keep it warm for 2~3 minutes; then move the titanium-steel composite pipe at a speed of 30~90mm / min, move it to the other end of the titanium-steel composite pipe and place it in the heating chamber, stop moving, and maintain the temperature at 950°C~1050°C for homogenization treatment for 30~40 minutes.

[0035] After pickling, roller straightening is performed. In steps S1 and S4, the pickling uses a mixture of hydrofluoric acid, nitric acid and water.

[0036] The matters not described in the following embodiments are the same as the description of the above specific implementation methods.

[0037] Example 1

[0038] A production process of titanium steel composite pipe, the specific process flow is:

[0039] S1: A titanium steel composite plate produced by explosive composite hot rolling is selected, and the slab size is (1+4) mm thick × 1264 mm wide × L mm, of which 1 mm thick is TA1 pure titanium and 4 mm thick is Q235 steel. After pickling, it is cut into titanium steel composite plates with a slab size of (1+4) mm thick × 632 mm wide × L mm as raw materials.

[0040] S2: The plate rolling machine rolls the plate into a tube with an outer diameter of 200 mm. The titanium layer is grooved at 30°, and the steel layer is grooved at 60°. The groove surface is cleaned with hydrochloric acid. The welding speed of each layer is 180 mm / min, and the current is 90 A. Argon gas is used to fully protect the weld area and nearby areas during the entire welding process.

[0041] S3: The welded tube blank is cold drawn three times by a drawing machine, and the size of the cold drawn tube is a titanium steel composite tube with an outer diameter of 150 mm;

[0042] The three-pass cold drawing process has a first pass cold drawing rate of 7.5%, a maximum drawing force of the drawing machine of 360T, and a drawing speed of 10mm / min; a second pass cold drawing rate of 13.5%, a maximum drawing force of the drawing machine of 410T, and a drawing speed of 30mm / min; and a third pass cold drawing rate of 6.3%, a maximum drawing force of the drawing machine of 380T, and a drawing speed of 15mm / min.

[0043] S4: Degreasing, annealing, pickling and straightening the cold-drawn titanium-steel composite tube to obtain a titanium-steel composite tube with an outer diameter of 150 mm;

[0044] In step S4, a medium frequency induction heating furnace is used to raise the temperature in the heating chamber to 1200°C and keep it warm for 2 minutes. Then, the titanium-steel composite pipe is moved at a speed of 50 mm / min until the other end of the titanium-steel composite pipe is placed in the heating chamber. The movement is stopped and the temperature is maintained at 1000°C for homogenization treatment for 30 minutes. The interface bonding strength of the obtained titanium-steel composite pipe is 180 MPa.

[0045] Example 2

[0046] A production process of titanium steel composite pipe, the specific process flow is:

[0047] S1: A titanium steel composite plate produced by explosive composite hot rolling is selected, and the slab size is (3+3) mm thick × 1000 mm wide × L mm, wherein a titanium steel composite slab with a thickness of 3 mm is TA2 pure titanium and a titanium steel composite slab with a thickness of 3 mm is Q235 steel as the raw material.

[0048] S2: The plate rolling machine rolls the plate into a tube with an outer diameter of 315 mm. The titanium layer is grooved at 35°, and the steel layer is grooved at 65°. The groove surface is cleaned with hydrochloric acid. The welding speed of each layer is 160 mm / min, and the current is 105 A. Argon gas is used to fully protect the weld area and nearby areas during the entire welding process.

[0049] S3: cold drawing the welded tube blank by a drawing machine, and the size of the cold-drawn tube is a titanium-steel composite tube with an outer diameter of 280 mm;

[0050] It is completed in one pass, of which the first pass cold drawing rate is 11.11%, the maximum drawing force of the drawing machine is 400T, and the drawing speed is 10mm / min.

[0051] S4: Degreasing, annealing, pickling and straightening the cold-drawn titanium-steel composite tube to obtain a titanium-steel composite tube with an outer diameter of 280 mm;

[0052] Among them, a medium frequency induction heating furnace was used to raise the temperature in the heating chamber to 1200°C and keep it warm for 3 minutes. Then, the titanium-steel composite pipe was moved at a speed of 50 mm / min, and the other end of the titanium-steel composite pipe was moved to the heating chamber. The movement was stopped and the temperature was maintained at 1020°C for homogenization treatment for 35 minutes. The interface bonding strength of the obtained titanium-steel composite pipe was 184 MPa.

[0053] Example 3

[0054] A production process of titanium steel composite pipe, the specific process flow is:

[0055] S1: A titanium steel composite plate produced by explosive composite hot rolling is selected, and the slab size is (4+8) mm thick × 1010 mm wide × L mm, wherein a titanium steel composite slab with a thickness of 4 mm is TA5 pure titanium and a thickness of 8 mm is X80 steel as raw materials.

[0056] S2: The plate rolling machine rolls the plate into a tube with an outer diameter of 320 mm. The titanium layer is grooved at 40°, and the steel layer is grooved at 80°. The groove surface is cleaned with hydrochloric acid. The welding speed of each layer is 100 mm / min, and the current is 140 A. Argon gas is used to fully protect the weld area and nearby areas during the entire welding process.

[0057] S3: Use a drawing machine to cold draw the welded tube billet twice, and the size of the cold drawn tube is a titanium steel composite tube with an outer diameter of 280 mm;

[0058] The two-pass cold drawing has a first pass cold drawing rate of 7%, a maximum drawing force of the drawing machine of 380T, and a drawing speed of 15mm / min; and a second pass cold drawing rate of 5.9%, a maximum drawing force of the drawing machine of 355T, and a drawing speed of 15mm / min.

[0059] S4: Degreasing, annealing, pickling and straightening the cold-drawn titanium-steel composite tube to obtain a titanium-steel composite tube with an outer diameter of 280 mm;

[0060] In step S4, a medium frequency induction heating furnace is used to raise the temperature in the heating chamber to 1250°C and keep it warm for 3 minutes. Then, the titanium-steel composite pipe is moved at a speed of 50 mm / min until the other end of the titanium-steel composite pipe is placed in the heating chamber. The movement is stopped and the temperature is maintained at 1040°C for homogenization treatment for 35 minutes. The interface bonding strength of the obtained titanium-steel composite pipe is 197 MPa.

[0061] For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A production process for titanium steel composite pipe, characterized in that: The production process comprises the following steps: S1: pure titanium and carbon steel are prepared into titanium steel composite plates by explosive composite hot rolling, and then cut after pickling; S2: rolling the titanium-steel composite plate obtained in step S1 into a tube, adopting a double-groove composite groove design for the edge of the titanium-steel composite plate, and after the groove processing is completed, performing multi-layer and multi-pass welding on the groove until it is built-up and flush with the base material; S3: performing multiple cold drawing on the titanium steel composite pipe welded in step S2 to obtain a cold drawn titanium steel composite pipe; S4: Degreasing, annealing, pickling and straightening the cold drawn titanium steel composite tube to obtain the titanium steel composite tube.

2. The production process according to claim 1, characterized in that: In step S2, the composite plate adopts a 30° double-groove composite groove design, in which one side of the pure titanium layer is a V-shaped groove with a groove angle of 30° to 40° and a depth equal to the thickness of the pure titanium layer; one side of the carbon steel layer is a V-shaped groove with a groove angle of 60° to 80° and a depth equal to the thickness of the carbon steel layer.

3. The production process according to claim 2, characterized in that: In step S2, the welding speed of each layer is 100-180 mm / min, and the current is 90-150 A; argon gas is used to protect the weld area and the surrounding area during the welding process.

4. The production process according to claim 3, characterized in that: In step S3, the cold drawing is performed for 1 to 5 passes each time, the cold drawing rate of each pass is controlled at 5% to 20%, the maximum drawing force of the drawing machine is 350 to 450 T, and the drawing speed is 10 to 40 mm / min.

5. The production process according to claim 4, characterized in that: In step S4, the degreasing is to use hydrocarbon solution to clean the lubricating oil on the inner and outer surfaces of the pipe.

6. The production process according to claim 5, characterized in that: In step S4, the annealing is to place one end of the titanium-steel composite tube in a heating chamber, start the electric heating furnace, raise the temperature in the heating chamber to 1150°C~1250°C, and keep it warm for 2~3 minutes; then move the titanium-steel composite tube at a speed of 30~90mm / min, move it to the other end of the titanium-steel composite tube and place it in the heating chamber, stop moving, and maintain the temperature at 950°C~1050°C for homogenization treatment for 30~40 minutes.

7. The production process according to claim 6, characterized in that: In step S4, roller straightening is performed after pickling.

8. The production process according to claim 7, characterized in that: In steps S1 and S4, the pickling is performed using a mixture of hydrofluoric acid, nitric acid and water.