Steel for marine riser and with excellent corrosion-resistant performance, and manufacturing method thereof

Abstract

The invention discloses steel for a marine riser and with excellent corrosion-resistant performance, and a manufacturing method thereof. The steel contains, by weight, 0.035%-0.060% of C, 0.10%-0.25%of Si, 1.26%-1.44% of Mn, 0.01%-0.04% of Nb, 0.011%-0.018% of Ti, 0.10%-0.20% of Cu, 0.06%-0.15% of Ni, 0.015%-0.040% of Als, 0.08%-0.18% of Cr, 0.0020%-0.0045% of N, no more than 0.009% of P, no morethan 0.001% of S, no more than 0.00015% of H, no more than 0.0020% of O, 3.42%-6.10% of Ti/N and the balance Fe and inevitable impurities. The heating process of a continuous casting billet is divided into four stages, the total heating time is 0.9-2.0 min/mm, the rough-rolling temperature interval is 1000-1150 DEG C, the finish-rolling temperature interval is 800-880 DEG C, the cooling temperature after rolling is 780-820 DEG C, and the final cooling temperature is 550-600 DEG C. A steel plate has good HIC and SSCC resisting performance.

Description

technical field [0001] The invention relates to the technical field of low-carbon micro-alloy steel, in particular to a steel plate for manufacturing marine drilling risers. Background technique [0002] Marine riser is a necessary equipment in offshore drilling engineering, mainly used in drilling, oil production, water injection and oil well maintenance and other fields of operation. The drilling riser is usually a large-diameter steel pipe. Its main function is to isolate seawater, protect the drill pipe, provide a circuit for drilling fluid circulation between the drilling ship or drilling platform and the subsea wellhead, and guide the drilling tool into the subsea wellhead. Because the riser works in the harsh environment of the ocean, it is a kind of oil drilling equipment with high risk, high difficulty, high technology and high added value, and is known as the "throat" of deepwater drilling development. At present, the price of marine risers in my country is very e...

AI Technical Summary

Problems solved by technology

[0006] CN104451431A discloses "a high-performance riser plate and its production method", which uses heat treatment to produce R t0.5 500~800MPa, R m It is a high-strength and low-temperature toughness high-strength riser plate with 600-1000 MPa and an impact energy greater than 200J at -80°C, but it is not mentioned in the invention that it has acid resistance

[0007] CN106367685A discloses "X80 and below steel grade pipeline steel for deep water drilling riser and its preparation method", its mechanical properties are transverse R t0.5 ≥555MPa,R m ≥670MPa, also belongs to high-strength water riser material, does not mention acid resistance

[0012] To sum up, the research on steel for risers with excellent corrosion resistance in the prior art is still insufficient

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