Large rolls of galvanized wire in oxygen violently extinguished, spark, and sodium block, magnesium strip in oxygen extinguished, no spark phenomenon. This phenomenon is determined by the composition of galvanized wire. The galvanized wire used in the experiment is pig iron or steel wire, pig iron and steel are iron and carbon alloy, containing iron and carbon two elements of complex material. Carbon in galvanized wire will produce carbon dioxide when extinguished, solid into gas, volume will shrink rapidly.

With the development of mining industry, pig iron classification in Our country has been very extensive, can satisfy the demand of machinery industry. In general, iron used to produce large coils of galvanized wire can be divided into two classes. A metal produced directly from iron ore and iron smelting, consisting of iron oxide, silicon dioxide, and other miscellaneous stones. When this ore is specially refined into metal iron, carbon, silicon, manganese, and other elements are mixed in, so that the refined material is called general pig iron, is also for the initial grade of the material.