When welding galvanized steel, the surface area of groove and also the side of the zinc layer under the activity of arc heat, oxidation, melting and also evaporation of white smoke and also vapor easily bring about weld porosity. ZnO formed by oxidation has a high melting point, above 1800 Β° C. If the specifications are also little in the welding process, ZnO slag inclusion will certainly be triggered. Meanwhile, as Zn ends up being a deoxidizer, FeO-MnO or Feo-Mno-Sio2 oxide slag addition with low melting factor will be created. It needs to be noted that the white dust of zinc volatilization is damaging to human body and the galvanized layer at welding need to be gotten rid of.