I450 seamless line pipe resistant to low temperature and hydrogen sulfide corrosion and manufacturing method thereof

Abstract

The invention discloses an L450 seamless line pipe resistant to low temperature and hydrogen sulfide corrosion and a manufacturing method thereof. Steel contains C: 0.10% to 0.15%, Si: 0.21% to 0.35%, Mn: 1.35% to 1.55%, Nb: 0.03% to 0.05%, Al: 0.025% to 0.035%, P≤0.015%, S≤ 0.005%, the balance is iron and unavoidable impurities. The final rolling temperature of the round billet continuous rolling is >980°C, the tube billet is heated to 1250-1280°C, the temperature after piercing is 1200-1220°C, and the sizing temperature is 855-875°C. The quenching heating temperature is 880-900°C, the quenching holding time is 40-60 minutes, the tempering temperature is 570-590°C, and the tempering holding time is 70-100 minutes. The finished steel pipe can meet the mechanical properties of L450-level pipeline pipes and resist HIC and SSC corrosion. Performance requirements, ‑40°C longitudinal impact Kv 8 ≥180J.

Description

technical field [0001] The invention relates to the field of seamless steel pipes with low temperature resistance and corrosion resistance materials, in particular to seamless line pipes with hydrogen sulfide corrosion resistance. Background technique [0002] Wet hydrogen sulfide environment is generally called acidic environment, and the corrosion of line pipes in acidic environment is a key factor affecting the reliability and service life of pipeline transportation systems. With the deepening of oil and gas well exploitation, H in natural gas 2 S content increased, H 2 S corrosion is inevitable. Seamless Line Pipe Internal H 2 S corrosion is one of the main forms of corrosion, which is mainly caused by hydrogen induced cracking (HIC) and sulfide stress cracking (SSC). Among them, hydrogen-induced cracking means that the metal material is immersed in the medium containing hydrogen sulfide, and the hydrogen precipitated during the electrochemical corrosion process ente...

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Problems solved by technology

The above three patents only pointed out the HIC resistance performance of the steel grades, and did not express their SSC resistance performance and low temperature resistance performance.

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