Non-quenched-tempered ocean engineering structure pipe with steel grade of more than 360MPa

Abstract

The invention relates to a non-quenched-tempered ocean engineering structure pipe with steel grade of more than 360MPa. The non-quenched-tempered ocean engineering structure pipe comprises the following component elements in percentage by weight: 0.02-0.12% of C, 0.17-0.35% of Si, 1.20-2.10% of Mn, less than or equal to 0.015% of P, less than or equal to 0.010% of S, less than or equal to 0.30% of Cu, 0.05-0.30% of Ni, less than or equal to 0.30% of Cr, less than or equal to 0.30% of Mo, 0.005-0.060% of Al, 0.03-0.12% of Nb, 0.005-0.030% of Ti, less than or equal to 0.40% of CE, 0.21% of Pcm, and the balance of Fe. The non-quenched-tempered ocean engineering structure pipe is scientific and reasonable in design, and adopts a low-carbon high-niobium steel design and a thermo-mechanically rolled non-quenching-tempering technology, and the non-quenched-tempered ocean engineering structure pipe with the steel grade of more than 360MPa is realized through transforming a rolling production line. Starting from the metallurgical design conception, offline quenching and tempering processing is not required, the production of the seamless steel pipe can be achieved only through thermo-mechanical rolling, the procedure cost of per ton can be reduced greatly, more importantly, the capacity can be greatly released, and the market competitiveness of domestic enterprises can be effectively improved.

Description

technical field [0001] The invention relates to an ocean drilling platform, in particular to a steel-grade non-quenched and tempered ocean engineering structural pipe above 360 ​​MPa. Background technique [0002] The jack-up drilling platform is a very widely used offshore mobile drilling platform. Generally, the platform is supported at the drilling position in the target sea area by three to four lifting legs. When working, the legs and spud cans are inserted into the bottom of the seabed A certain depth to support the drilling platform and maintain stability. Structural seamless steel pipes for marine engineering with a steel grade above 360MPa usually need to have high impact toughness in marine low-temperature service environments (below -20°C). Restricted by the type of seamless steel pipe production process, this steel grade seamless line pipe cannot reach its performance index through thermomechanical rolling control (TMCP) + accelerated cooling (ACC), and usually ...

AI Technical Summary

Problems solved by technology

Restricted by the type of seamless steel pipe production process, this steel grade seamless line pipe cannot reach its performance index through thermomechanical rolling control (TMCP) + accelerated cooling (ACC), and usually needs to be processed offline (offline) or online (online) heat treatment (quenching + tempering) can only be realized, which will increase the process cost of seamless steel pipe production

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