Manufacturing method of submerged pipeline steel pipe

Abstract

The invention discloses a manufacturing method of a submerged pipeline steel pipe, which comprises the following technological processes of: raw material inspection, steel pipe welding and weld heat treatment, wherein the process of steel pipe welding adopts high frequency induction welding. The raw materials comprise the following chemical components: 0.04-0.08% of C, not more than 0.25% of Si, not more than 1.65% of Mn, not more than 0.020% of P which is less than or equal to, not more than 0.005% of S, not more than 0.15% of Nb+V+Ti, and not more than 0.41% of Ce. Because the technical scheme is adopted, the chemical components with low carbon content, low manganese content and microalloy are determined, and the maximum value of harmful elements and the content ratio of microalloy elements are controlled, thereby achieving the purposes of refining grains and improving the performance indexes of products; and the products have high strength, corrosion resistance and high pressure resistance.

Description

technical field [0001] The invention relates to the metallurgical industry, in particular to a method for manufacturing ERW steel pipes for X70 grade high-strength submarine pipelines. Background technique [0002] At present, ERW high-frequency straight seam welded pipe is a kind of high-quality, medium and small-diameter steel pipe commonly used in pipelines for transporting oil and natural gas. In 2006, ERW steel pipe was used for the first time in China for submarine pipeline projects. The general specification is φ219mm-φ610mm. Because ERW steel pipe has With many advantages such as high strength, high conveying pressure, high pipe diameter precision, high production efficiency, and good economical practicability, it has been preferentially and widely used in the field of pipelines for oil and gas transmission. X70 grade high-strength submarine pipeline steel pipe has the advantages of corrosion resistance, high strength and high extrusion force resistance. The successf...

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Problems solved by technology

X70 grade high-strength submarine pipeline steel pipe has the advantages of corrosion resistance, high strength and high extrusion force resistance. The successful invention can be widely applied to the seabed and offshore oil and gas pipelines with relatively poor environmental conditions and corrosive media. Inquire Domestic and foreign network databases searched and consulted relevant documents, but did not check the same patent documents and public reports on X70 grade high-strength submarine pipeline steel pipes. At present, domestic production is limited to X60 grade submarine pipeline steel pipes, while X70 grade high-strength steel pipes The actual annual domestic demand for steel pipes for submarine pipelines shows an increasing trend year by year. At present, domestic X70 grade steel pipes for submarine pipelines have long relied on imports from the international market or replaced them with seamless pipes. Uniform weakness, so it is of great significance to develop X70 high-strength submarine pipeline steel pipes

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