Common rust removal method for ships

Common rust removal methods for ships include manual rust removal, mechanical rust removal, and chemical rust removal.

First, manual rust removal Manual rust removal tool has a hammer, blade, scraper, wire brush, etc., generally thick rust spots with a hammer hit loose and then use a shovel to eradicate. High labor intensity, low rust removal efficiency, generally 0.2 ~ 0.5m2/h, bad environment, difficult to remove dirt such as oxide scale, poor rust removal, difficult to achieve the required cleanliness and roughness, has gradually been mechanical Fang Han Replaced by chemical methods. However, in the process of repairing ships, especially for the repair of local defects, this method is often used. For areas where mechanical derusting is difficult to achieve, such as narrow cabins, and difficult working areas such as corners and back edges of steel sections, manual derusting is also applied.

Second, mechanical derusting machinery rust removal tools and processes are more, of which the main four are:

1, small wind or electric rust. Mainly powered by electricity or compressed air, equipped with appropriate rust removal equipment, reciprocating or rotary motion to meet the rust removal requirements of various occasions. Such as angle grinder, wire brush, pneumatic needle rust remover, pneumatic rust hammer, tooth rotation rust remover, etc., are semi-mechanized equipment, tools, lightweight, mobility, can completely remove rust , The old coating, etc., can be used for roughing the coating. The efficiency is much higher than that of manual rust removal, up to 1~2m2/h, but oxide scale can not be removed, the surface roughness is small, and the quality of surface treatment cannot be achieved The ergonomics are lower than the jet treatment. Can be used in any location, especially in the ship repair process has been widely used.

2, blasting (sand) rust. It mainly consists of particle jet erosion to achieve surface cleanliness and appropriate roughness. The equipment includes open shot blasting (sand) rust remover, closed shot peening (sand chamber), vacuum shot peening (sand) machine. The open blasting (sand) machine is widely used and can completely remove all impurities on the metal surface, such as oxide scale, rust, and old paint film. The rust removal efficiency is high 4~5m2/h, the mechanical degree is high, and the rust removal quality is high. it is good. However, due to the fact that abrasive materials are generally not recovered, they will affect other operations and clean up the site. Therefore, environmental pollution is heavier and has recently been restricted to use.

3, high pressure water abrasive rust removal. The impact of the high-pressure water jet (plus the grinding action of the abrasive) and the hydrazine action destroy the adhesion of the rust and the coating to the steel plate. Its characteristics are no dust pollution, no damage to the steel plate, greatly improve the efficiency of rust removal, up to 15m2/h, good quality of rust removal. However, after the rust-removing steel sheet is easy to return to rust, a special wet rust-removing coating must be applied, which has a large influence on the coating of general performance coatings.

4, shot blasting rust. Shot blasting is the use of high-speed rotating impeller to throw abrasive on the steel surface to achieve the purpose of rust removal. It is a more advanced mechanical treatment method for removing rust from the hull steel material. It not only has high production efficiency, but also has low cost and automation. High level, can achieve assembly line operation, less environmental pollution, but only operate indoors.

Third, chemical rust removal is mainly the use of acid and metal oxide chemical reaction, so as to remove metal surface corrosion products of a rust removal method, which is commonly referred to as pickling rust, can only be operated in the workshop.