black phosphate screws

Out-of-line annealing means that the recrystallization annealing of hot or cold rolled steel plate is carried out in the bottom type annealing furnace or cover type annealing furnace before entering the hot plating wire line, so that there is no annealing process in the galvanized line. The steel plate must maintain a clean active surface of pure iron, free of oxides and other dirt, before hot dip galvanizing. In this method, the annealed surface oxide sheet is first removed by pickling method, and then coated with a layer of zinc chloride or a mixture of ammonium chloride and zinc chloride solvent for protection, so as to prevent the plate from being oxidized again.

However, because the plating solution contains highly toxic cyanide, the gas escaping in the plating process is harmful to the health of workers, and the waste water must be treated strictly before discharge. Galvanized iron wire has good anti-corrosion and anti-rust ability, so it can be prevented from being used in some outdoor guardrail or fence, especially on handicrafts, handicrafts are also of great use, galvanized iron wire, the surface is not easy to rust and oxidation.

Bridge protection system generally do not need to be specially installed special drainage system, the use of hexagonal mesh made of gabion mesh box, the inside of the filler are selected stones, these stones are not easy to wear, and between the stones and stones will retain some gaps, so it is very good to meet the drainage requirements.