Seamless mother pipe of mechanical composite pipe for acid environment

Abstract

The invention relates to a seamless mother pipe of a mechanical composite pipe for an acid environment. The mother pipe comprises the following components in percentage by weight: 0.06% < = C < = 0.12%; 0.10% < = Si < = 0.30%; 1.00% < = Mn < = 1.60%; 0.02% < = Nb < = 0.10%; 0.04% < = V < = 0.10%; 0.20% or less of Ni + Mo; less than or equal to 0.20% of Cr + Cu; other elements and the balance Fe; the mechanical composite line pipe mother pipe for the acid environment can achieve high dimensional precision (the inner diameter of the pipe end is + / -1 mm, the ovality is smaller than or equal to 3 mm, and the diameter difference between pipes is smaller than or equal to 1.6 mm), high performance stability (the strength fluctuation range is smaller than or equal to 80 MPa), high toughness (the ductile-brittle transition temperature is smaller than or equal to-60 DEG C), high ductility (the ductility is larger than or equal to 30% (plate)) and high SSC corrosion resistance (90% AYS four-point bending does not break for 720 hours).

Description

technical field [0001] The invention belongs to the technical field of oil and gas transportation pipes, in particular to a seamless parent pipe of a mechanical composite pipe used in an acidic environment. Background technique [0002] As the conditions of oil and gas extraction and transportation continue to deteriorate, the oil and gas extracted and transported become more complex, and the demand for composite pipes is increasing. Composite pipe, that is, the base material is carbon steel pipe, and the composite layer is 316L stainless steel or duplex stainless steel or nickel-based alloy. The parent pipe ensures the basic strength, and the composite layer ensures sufficient corrosion allowance, so as to meet the use requirements of the transportation environment in harsh environments. Compared with ordinary line pipe, the seamless parent pipe of composite pipe has special characteristics. For the parent pipe, the composition is stable, the performance fluctuation (the di...

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Problems solved by technology

[0004] In order to solve the problems existing in the above-mentioned technologies, the object of the present invention is to provide a mechanical composite pipe master pipe for acidic environment, to meet the needs of the development of harsh environments such as deep sea, and to solve the situation of mechanical composite pipe The performance is unstable, the size is inconsistent and cannot meet the design requirements

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