A spiral formed x80 steel grade riser main pipe and its manufacturing method

Abstract

The invention discloses a spirally-formed X80 steel grade main riser. The main riser comprises the chemical components of, by mass, 0.04-0.08% or less of C, 0.15-0.35% of Si, 1.55-1.85% of Mn, 0.012% or less of P, 0.004% or less of S, 0.15-0.30% of Ni, 0.15-0,30% of Cr, 0.10-0.30% of Cu, 0.15-0.30% of Mo, 0.03-0.06% of Nb, 0.06% or less of V, 0.06% or less of Ti, 0.04% or less of Al and the balance Fe and inevitable impurities, wherein the carbon equivalent Ceq is equal to or less than 0.45%, and CEpcm is equal to or less than 0.22%. The main riser adopts a hot rolling coiled plate as a raw material, and a composite fine-crystal structure combining a needle-shaped ferrite and a bainite is adopted as the main structure. The spirally-formed X80 steel grade main riser is high in strength and dimensional precision and has excellent comprehensive properties such as the anti-fatigue property, the anti-fracture property and the anti-corrosion property.

Description

Technical field: [0001] The invention relates to the technical field of oil pipes, in particular to a spirally formed X80 steel grade riser main pipe and a manufacturing method thereof. Background technique: [0002] With the increasing demand of human beings for energy, the ocean has become a new field of global resource development. The offshore drilling riser supervisor is an important equipment unit of the ocean drilling riser system. It is an important component connecting the subsea wellhead and the drilling ship. Technology The index requirements are relatively high, especially for the geometric dimension accuracy of the welded pipe, and the development is difficult. It is a kind of oil drilling and production equipment with high risk, high difficulty, high technology and high added value. [0003] In recent years, the marine drilling riser's ability to adapt to seawater depths has exceeded 3,000 meters. At present, only the United States, Norway, Japan, France and o...

AI Technical Summary

Problems solved by technology

In recent years, although my country has done some work in the research of offshore drilling riser management theory and accumulated some experience in riser maintenance, it has not yet entered the stage of substantive product formation and achieved domestic engineering application.

Images