copper clad flat steel 1, copper layer average thickness than 0.25mm; 2, ... welding powder, grounding electrode, GEM and so on. copper clad flat steel 1, copper layer average thickness (conventional) ≥ 0.25mm; 2 ... , salinity, acid soil and chemical corrosion medium), petrochemical, power, communications, rail transport, post and telecommunications, such as lightning protection grounding requirements ...