X90/X100 steel bent pipe and manufacturing method thereof

Abstract

The invention provides an X90 / X100 steel elbow and a manufacturing method thereof, which is made of an X90 / X100 steel grade LSAW parent pipe, and the groove structure of the pipe end of the elbow is sequentially arranged from the outer ring to the inner ring are the first slope segment, the second slope segment and the vertical segment. The manufacturing method of the present invention includes the following steps: setting bending process parameters; placing the LSAW mother pipe on an intermediate frequency induction pipe bending machine; heating the pipe body through an induction heating coil, and the heating temperature is 950-1050°C ;The steel pipe is pushed forward, bent and formed into a 10°-90° elbow, and the pipe body is cooled by spraying water at the same time; the intermediate frequency heating temperature and the propulsion speed are controlled. The bent pipe has excellent comprehensive mechanical properties, overcomes the defect of outer arc thinning and out-of-tolerance, has high roundness of the cross section of the bent part, and has good toughness especially in low temperature environments.

Description

technical field [0001] The invention relates to a pipe fitting for oil and gas transportation, in particular to an X90 / X100 steel elbow and a manufacturing method thereof. Background technique [0002] In petrochemical, electric power, metallurgy, boiler and other industrial production equipment, pipelines are widely used for conveying gas, liquid or fluid with solid particles. [0003] The development trend of long-distance natural gas pipeline projects in China is to further increase the transmission volume and reduce construction costs as much as possible. With the signing of oil and gas supply agreements with Central Asian countries and Russia, it is necessary to build natural gas pipelines with a transmission capacity of 45 billion to 60 billion m3 / a. The second-generation (X70 and X80) natural gas pipeline engineering technology can no longer meet the needs of super-large transmission volume, and it is necessary to develop a new generation (third-generation) pipeline ...

AI Technical Summary

Problems solved by technology

The second-generation (X70 and X80) natural gas pipeline engineering technology can no longer meet the needs of super-large transmission volume, and it is necessary to develop a new generation (third-generation) pipeline engineering technology (steel grade X90 / X100, pipe diameter 1219-1422mm, pressure not lower than 12MPa)

However, at present, the elbows for high-grade oil and gas pipelines with a diameter of 1200mm or more for oil and gas transportation have not yet been developed in China, and they mainly rely on imports, while the elbows with a diameter of 1422mm used in the Sino-Russian East Line natural gas transmission are still blank

For a long time, troubled by environmental conditions, raw materials and processing technology, the elbows for oil and gas transportation in low-temperature areas have always been heat-insulated by electric or steam tracing, which virtually increases the difficulty of construction and operating costs, and increases a large number of maintenance tasks

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