If the zinc coating is good, but in 3% nitric acid when the light, the coating has dark shadow, passivation occurs when the film is brown, may be caused by foreign metal impurities such as copper or lead in the galvanizing liquid. When problems occur in the process of galvanizing large coil galvanized wire, the temperature and current density are checked first, and then the content of zinc and sodium hydroxide in the plating solution is measured and adjusted through the analysis of the plating solution. Whether DPE content is low can be determined by hull cell test.

Hot dip galvanizing is also called hot dip zinc and hot dip galvanizing: is an effective way of metal corrosion, mainly used in various industries of metal structure facilities. It is to immerse the steel parts after rust removal into the molten zinc liquid at about 500℃, so that the surface of the steel parts is attached with zinc layer, so as to play the purpose of anticorrosion. Hot dip galvanizing process: finished product pickling – washing – adding bath aid – drying – hanging plating – cooling – drug – cleaning – grinding – hot dip galvanizing completion. Hot dip galvanizing is developed from the older method of hot dip galvanizing. It has a history of 140 years since it was applied to industry in France in 1836. However, the hot dip galvanizing industry has been developed on a large scale in the past 30 years with the rapid development of hot dip galvanizing wire.

With the development of mining industry, pig iron classification in Our country has been very extensive, to meet the needs of the machinery industry. Generally speaking, iron wire factory produces galvanized iron wire iron can be divided into two categories, is directly from the iron ore through iron tracing exercise out of the metal, the primary components of the ore is iron oxide, silica and other miscellaneous stones. When this ore is specially refined into metal iron, the elements such as carbon, silicon, manganese and so on are mixed in, so that the refined data is called – like general pig iron, also for the initial grade of the material.