Performance requirements of offshore platform steel

Because offshore platforms are immersed in seawater all the year round, they have to endure all kinds of harsh sea conditions. Therefore, the technical specifications of offshore platform steel are very high. It requires not only high atmospheric corrosion resistance and seawater corrosion resistance, but also good mechanical and processing performance. The performance requirements of offshore platform steel include:

Offshore platform steel has high strength and resists wind impact above water surface. It has good resistance to layered tearing and avoids tearing when offshore platform steel is subjected to external force in thickness direction.

Offshore platform steel has good low temperature impact performance. Some offshore platform steels need to have good impact performance at - 60 C and can be used in extremely cold environment.

Offshore platform steel has good weldability, and the welded joint has the same or similar mechanical properties as the base metal to ensure the safety of the overall structure of the offshore platform.

Purity requirement of offshore platform steel. Offshore platform steel should have a low content of impurity elements such as P and S, and have a high requirement on the morphology, type and distribution of inclusions, so as to avoid fatigue failure of offshore platforms under the influence of typhoon and current movement, and to ensure the safety of life and property.

Requirements for corrosion resistance. Because the marine steel structure has been in the environment of salt fog, moisture and sea water for a long time, it is subject to the erosion of sea water and marine organisms, resulting in intense electrochemical corrosion. The paint film is prone to severe saponification and aging, resulting in very serious structural corrosion, which not only reduces the mechanical properties of structural materials, shortens their service life, but also because it is far from the coast, it can not be repaired and maintained regularly like a ship. Therefore, the requirement for corrosion resistance of offshore platform steel is higher.

In view of a series of structural component rupture disasters occurring in offshore structures and facilities, the requirements for the production and application of crack-arresting performance offshore platform steel plates have been put forward in the international engineering field, and relevant international standards are being formed and promoted.