Chemical etching of spiral piling pipe

In nature, the material will dissolve in a solution are well known specific phenomena, such as: sugar, salt will dissolve in water, or a plurality of metal or non-metal will dissolve in hydrochloric acid. Sometimes we can take advantage of these features in the manufacturing method, for example: the use of ferric chloride to etch the copper art or circuit board. However, the use of materials in construction, most of the coil is still considered prevention of corrosion of spiral piling pipe.

In general, the metal, the solution is most likely to erode the position of the grain and grain joining the Department, which is the grain boundary, and then continued to grow, sometimes chemical corrosion or the formation of compounds with the environment changes, it may be accompanied by electrochemical etching from, of course, if this is the case, the corrosion phenomenon will become more complicated.

1. Selective filter
Some metal alloy materials under special circumstances, one or more elements which are selectively filtered easily (leach) or called corrosion, and become porous residues, thereby reducing the mechanical properties, such phenomenon called selective filter. This phenomenon, related to the nature and metal, such as zinc contained in the brass at high temperatures will be dissolved in the aqueous solution of salts, produced dezincification (dezincification) localized corrosion phenomena, and the lack of zinc position, so that yellow copper becomes porous structure and becomes very fragile.

2. Graphite corrosion
Graphite corrosion is another example of a similar selective etching, flake graphite cast iron is staggered in the iron-based organizations, if placed in water or soil, the iron will of the graphite anode compared with the more cathodic the Therefore part of the iron will corrode, and the formation of a porous appearance, the gray cast iron pipes, have a positive corrosion measures, if properly buried, prone to leakage or explosion event.

Chemical corrosion prevention and control is extremely difficult, the coating material is a way to avoid the material with the solution (especially easy to play, with pH solution) contact is another way to solve. If it must be used in an environment in solution must be considered when selecting a material resistant to chemical corrosion. For example: In order to suppress the phenomenon of dezincification brass, we can more than 15% zinc brass, add about 1% Sn Sb, in order to resist such corrosion and increases strength. Such tin-containing brass include: Navy brass (naval brass), the sea will be brass (admiralty metal) are examples of it.