Because the offshore platform is immersed in seawater all the year round, it has to withstand various harsh sea conditions. Therefore, the technical indicators of the steel used for the offshore platform are extremely high, not only must have high atmospheric corrosion resistance and seawater corrosion resistance, but also require good Mechanical and processing properties, etc.
Steel for marine engineering has high strength and can resist the impact of wind and current above the water surface. It has good resistance to lamellar tearing and prevents the steel from tearing when it is subjected to external force in the thickness direction.
Steel for offshore engineering has good low-temperature impact properties, and some steels for offshore platforms need to have good impact properties at -60°C and can serve in extremely cold environments.
The steel used in marine engineering has good welding performance, and the performance of welded joints has the same or similar mechanical properties as the base metal, ensuring the safety of the overall structure of the offshore platform.
Steel purity requirements for steel used in marine engineering. Steel must have very low content of impurity elements such as P and S, and have high requirements on the shape, type and distribution of inclusions, so as to avoid fatigue failure of offshore platforms when they are affected by typhoons and water movement, and to ensure life and safety. Property security.
Requirements for corrosion resistance of steel used in marine engineering. Since the marine steel structure has been in the environment of salt spray, moisture and seawater for a long time, severe electrochemical corrosion occurs due to the erosion of seawater and marine organisms, and the paint film is prone to severe saponification and aging, resulting in very serious structural corrosion. It reduces the mechanical properties of structural materials and shortens their service life, and because they are far away from the coast, they cannot be regularly repaired and maintained like ships. Therefore, the requirements for its corrosion resistance are higher.
