steel perforated round angle

After proper heat treatment or cold drawing hardening, high carbon steel wire has high strength and hardness, high elastic limit and fatigue limit (especially notched fatigue limit), cutting function is acceptable, but welding function and cold plastic deformation ability is poor.

If the zinc coating is good, but when the light comes out in 3% nitric acid, there is a dark shadow on the coating, and the film is brown when passivation occurs, which may be caused by foreign metal impurities such as copper or lead in the galvanized liquid. When there is a problem in the process of galvanizing, check the temperature and current density first, and then measure and adjust the content of zinc and sodium hydroxide in the bath through the analysis of the bath. Whether DPE levels are low can be determined by Hull cell test.

When the zinc layer is seriously damaged and endangers the iron matrix, the zinc will produce electrochemical protection on the matrix, the standard potential of zinc is -0.76V and the standard potential of iron is -0.44V. When zinc and iron form microbatteries, the zinc will be dissolved as the anode, and the iron will be protected as the cathode. Obviously, the atmospheric corrosion resistance of hot dip galvanizing is better than that of electric galvanizing.