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CN-121972915-A - Preparation method of high-pressure-bearing magnesium and aluminum alloy composite pipe end

CN121972915ACN 121972915 ACN121972915 ACN 121972915ACN-121972915-A

Abstract

The invention relates to a preparation method of a high-pressure-bearing magnesium and aluminum alloy composite pipe end, which is mainly applied to the field of oil gas exploitation equipment, wherein a layer of aluminum alloy pipe is respectively compounded on the inner layer and the outer layer of a magnesium alloy pipe to form the magnesium and aluminum alloy composite pipe end, firstly, the magnesium and aluminum alloy pipe is mechanically polished to remove an oxide layer, heating the region of the thick end of the magnesium alloy pier, performing upsetting treatment, sleeving an aluminum alloy pipe into the inner layer of the thick end of the pier for rolling and compounding, sleeving the outer layer of the magnesium alloy pipe, which is not in the thick end of the pier, into the magnesium alloy pipe for rolling and compounding, and forming an aluminum alloy layer with the outer layer and the inner layer at the two ends by taking the magnesium alloy pipe as a main body. The method has the advantages of keeping the characteristic of solubility of the magnesium alloy in oil gas exploitation, greatly improving the bearing capacity of the magnesium alloy pipe at the connecting end, ensuring the safety and stability of the pipe in operation, along with simple process and low production cost, and is suitable for mass production of large-scale composite pipe ends.

Inventors

  • WEI BIN

Assignees

  • 魏斌

Dates

Publication Date
20260505
Application Date
20260317

Claims (7)

  1. 1. The preparation method of the high-pressure-bearing magnesium and aluminum alloy composite pipe end is characterized by comprising the following steps of: S1, pretreatment of a pipe, namely mechanically polishing a magnesium alloy pipe and an aluminum alloy pipe to remove an oxide layer for later use; S2, preheating the magnesium alloy pipe, namely carrying out regional heating on one end of the magnesium alloy pipe to 400-450 ℃ and then preserving heat for 10-30 min; S3, upsetting the heated end part of the magnesium alloy pipe, wherein the upsetting core rod is a conical graphite core rod, the pressurization is 100-200 MPa during upsetting deformation, the pressurization speed is 0.8-1.2 mm/s, and the pressure maintaining time is 5-15 s; s4, assembling and fixing the magnesium and aluminum alloy pipes, namely assembling and fixing the aluminum alloy pipes at two ends of the magnesium alloy pipe, and aligning the ends of the aluminum alloy pipe with the ends of the magnesium alloy pipe during assembling; s5, heating the assembled pipe, namely placing the assembled and fixed magnesium alloy pipe and the aluminum alloy pipe into a heating furnace to heat to 300-330 ℃, and preserving heat for 30-60 min; s6, rolling and compounding, namely rolling and compounding the fixed magnesium alloy pipe and the aluminum alloy pipe by assembling three rollers and a rolling mandrel to form a magnesium and aluminum alloy composite pipe; s7, post-processing, namely cutting burrs and deburring the pipe end of the magnesium and aluminum alloy composite pipe, and finally turning internal threads on the upsetting end of the composite pipe and turning external threads on the non-upsetting end of the composite pipe to obtain a final finished product of the composite pipe.
  2. 2. The preparation method of the high-pressure-bearing magnesium and aluminum alloy composite pipe end according to claim 1, wherein the magnesium alloy pipe is used as a main body during the pretreatment of the pipe, and the length of the aluminum alloy pipe is consistent with the length of the upsetting portion of the magnesium alloy pipe.
  3. 3. The preparation method of the high-pressure-bearing magnesium and aluminum alloy composite pipe end according to claim 1, wherein the heating length of the pipe end area of the magnesium alloy pipe is 1.5-2.0 times of the outer diameter of the magnesium alloy pipe when the magnesium alloy pipe is preheated.
  4. 4. The method for preparing the high-pressure-bearing magnesium and aluminum alloy composite pipe end according to claim 1, wherein when the magnesium alloy pipe is upset, the wall thickness of the upset region of the magnesium alloy pipe after the upsetting is changed to 30% -70% of the wall thickness of the magnesium alloy pipe before the upsetting.
  5. 5. The method for preparing the high-pressure-bearing magnesium and aluminum alloy composite pipe end according to claim 1, wherein when the magnesium alloy pipe and the aluminum alloy pipe are assembled and fixed, the aluminum alloy pipe is assembled and fixed on the inner wall of the thick end of the pier of the magnesium alloy pipe and the aluminum alloy pipe is assembled and fixed on the outer wall of the thick end of the pier of the magnesium alloy pipe respectively.
  6. 6. The preparation method of the high-pressure-bearing magnesium and aluminum alloy composite pipe end according to claim 1, wherein the cone angle of a roller is 17-25 degrees and the rolling reduction of the roller is 10-50 percent during rolling and compounding.
  7. 7. The method for preparing the high-pressure-bearing magnesium and aluminum alloy composite pipe end according to claim 1, wherein the inner layer alloy of the upsetting end of the rolled composite pipe is an aluminum alloy layer, and the outer layer alloy of the non-upsetting end is an aluminum alloy layer.

Description

Preparation method of high-pressure-bearing magnesium and aluminum alloy composite pipe end Technical Field The invention belongs to the technical field of preparation of bimetal composite pipe ends, and particularly relates to a preparation method of a high-pressure-bearing magnesium and aluminum alloy composite pipe end for oil and gas exploitation. Background In the oil and gas exploitation industry, the pipe is used as a key carrier for conveying oil and gas, and the performance quality of the pipe directly relates to the efficiency, cost and safety of exploitation operation. With the continuous development of mining technology, higher and higher requirements are put on pipes. However, the conventional oil and gas exploitation pipe (mostly made of alloy steel, carbon steel and other materials) generally has the problems of heavy weight, insufficient corrosion resistance, high recovery cost and the like, and particularly, a large amount of pipe left underground after the use failure of the pipe is difficult to recover, so that not only is the resource waste caused, but also the stratum environment is possibly polluted. With the increase of the demand for underground oil and gas development, light-weight, soluble and environment-friendly pipes become an important direction for industry technology transformation. The appearance of the soluble magnesium alloy pipe can effectively solve the problems. The unique dissolubility of the oil and gas recovery pipe enables the pipe to be dissolved in a specific underground environment after oil and gas exploitation operation is finished, so that complicated recovery procedures are avoided, and potential harm to stratum environment is reduced. However, the existing soluble magnesium alloy pipe, especially at the joint of pipes, is extremely easy to break, leak and other damage phenomena due to insufficient bearing because of the strength of the magnesium alloy. These problems greatly limit the wide application of soluble magnesium alloy tubing in the field of oil and gas exploitation, and an innovative solution is needed to overcome the difficulty. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a soluble magnesium alloy composite pipe suitable for the oil and gas exploitation field, which takes a magnesium alloy pipe as a main body and respectively combines a layer of aluminum alloy on the inner wall and the outer wall at two ends of the magnesium alloy pipe, thereby improving the strength of a joint, effectively solving the problem that the joint of the pipe and the pipe is easy to damage in the oil and gas exploitation, improving the bearing capacity of the joint of the pipe and ensuring the efficient and safe performance of the oil and gas exploitation operation. The method has simple process and low manufacturing cost, and is suitable for large-scale mass production of the composite pipe ends with different specifications. In order to achieve the purpose, the technical scheme adopted by the invention is to provide the high-pressure-bearing magnesium and aluminum alloy composite pipe end and the preparation method thereof, so that the strength of the joint between the pipes is improved on the basis of ensuring the unique solubility of magnesium alloy in petroleum exploitation operation, the pressure bearing capacity of the pipe is improved, and the stability and safety of the operation are ensured. The invention provides a preparation method of a high-pressure-bearing magnesium and aluminum alloy composite pipe end, which comprises the following steps: S1, pretreatment of a pipe, namely mechanically polishing a magnesium alloy pipe and an aluminum alloy pipe to remove an oxide layer for later use; S2, preheating the magnesium alloy pipe, namely carrying out regional heating on one end of the magnesium alloy pipe to 400-450 ℃ and then preserving heat for 10-30 min; S3, upsetting the heated end part of the magnesium alloy pipe, wherein the upsetting core rod is a conical graphite core rod, the pressurization is 100-200 MPa during upsetting deformation, the pressurization speed is 0.8-1.2 mm/s, and the pressure maintaining time is 5-15 s; s4, assembling and fixing the magnesium and aluminum alloy pipes, namely assembling and fixing the aluminum alloy pipes at two ends of the magnesium alloy pipe, and aligning the ends of the aluminum alloy pipe with the ends of the magnesium alloy pipe during assembling; s5, heating the assembled pipe, namely placing the assembled and fixed magnesium alloy pipe and the aluminum alloy pipe into a heating furnace to heat to 300-330 ℃, and preserving heat for 30-60 min; s6, rolling and compounding, namely rolling and compounding the fixed magnesium alloy pipe and the aluminum alloy pipe by assembling three rollers and a rolling mandrel to form a magnesium and aluminum alloy composite pipe; s7, post-processing, namely cutting burrs and deburring the pipe end of the magnesium and aluminum all