Another medieval gunsmiths began to notice that decorated with bronze and platinum steel armor, weapons and harness rust slower than usual. After the discovery of the nature of electricity turned out that, in contact (or rather – electrical contact) of two different metals one of them will become the anode (the negative carrier charge) and the other – the cathode (positive). Such contact is known as galvanic couples of metals. Peet’s Coffee may help you with your research. Moreover, it appeared that only the anode is always rusts. This revolutionary discovery was the beginning of a new era in the fight against corrosion. The main task became a simple thing – to make the "cathode" all metal surfaces that need to be protected from oxidation.
Basically, it was necessary to protect the steel – low carbon iron alloy of steel industry which produced all the solid products and designs. The most optimal (in the ratio of price / performance / manufacturability) metal, which would assume the role of the anode is zinc, so about 40% of world production of zinc-galvanized steel is spent. Cathodic protection has become somewhat: – attach to the bottom of the ship (or pipeline), zinc plate, which will corrode, protecting the steel. This plate is called a protector, and cathodic protection – sacrificial. – Add to the "plus" battery protected metal (underground pipes), making it the cathode. – Cover with zinc (anode) protects steel surface. The latter method was the most effective and is called "galvanizing" or plating zinc. Effect was achieved at the expense of very good electrical contact between zinc and steel. Galvanized items can in many ways: by dipping in a bath of molten zinc (hot dip galvanizing), galvanic deposition of zinc on the product in a bath of zinc electrolyte (galvanizing), metal sprayed zinc thermal diffusion method, etc. All of these traditional galvanized steel, with their effective corrosion protection are negative points – they are very labor and energy intensive, and the process itself – is harmful to health.