Multi-layer Coating Long-term Anti-corrosion Technology of Steel Structure Equipment in Marine Splash Zone

Sea is a kind of very harsh corrosive environment, especially the splash zone. The surface of the steel is periodically wet by the seawater. It is always under the alternate state of dry and wet. The sufficient oxygen is supplied. The salt is continuously concentrated. Besides, under the synergistic effect of sunshine, wind and seawater, the corrosion is very serious. In general, for the same steel, the corrosive speed in the splash zone will be 3~10 times faster than that in the immersion zone of sea. 

◆The construction is affected by the size of the waves. While the site condition is poor, the danger coefficient will be high. Influenced by the tide, the construction will be difficult.

◆The corrosion in the marine splash zone is more serious. The average corrosive speed is about 0.3~0.5 mm per year. 

◆The paralic environment will be hit by large flotages such as ship. Hence, it puts forward higher requirement on anti-corrosion strength of the steel structure.

The multi-layer coating anti-corrosion technology of the steel structure in the marine splash zone is composed of the anti-corrosion cream, anti-corrosion belt and anti-corrosion protection cover, as shown in the following picture. The anti-corrosion cream and belt are the hydrophobic corrosion resistant material, having the good protection effect and adhesion. They are insulated from water and air. Also, they will not go bad for a long time. They strongly adhere to the surface of steel equipment to reach the long-term anti-corrosion effect. Additionally, the hard protection cover and anti-corrosion belt are used to achieve better protection effect. 

◆It applies the cold construction. It doesn’t need the sandblast, flame operation and solidification. The construction is simple.  

◆ The construction is convenient and the surface treatment is simple. It can be operated with water.

◆The requirement for surface treatment is low. It is OK to reach St2 level.

◆ The anti-corrosion cream and belt contain the inhibitor and rust converter which have the double effect of rust inhibiting and removal.

◆It has the good impermeability and anti-aging performance. The service life of anti-corrosion material is over 30years. The overall anti-corrosion duration is up to 20years.