What are the causes of white rust and black spots on galvanized iron wire?

What are the causes of white rust and black spots on galvanized iron wire?
(1) Poor passivation, insufficient or uneven passivation film thickness;
(2) The surface is not oiled or the residual moisture on the strip surface;
(3) The surface of the strip contains moisture when coiling;
(4) Passivation is not completely dried;
(5) getting wet or rainy during transportation or storage;
(6) The finished product storage time is too long;
(7) The galvanized sheet is in contact with or stored together with other corrosive media such as acid and alkali.
What are the main reasons for the zinc layer falling off?

The main causes of zinc layer detachment are: surface oxidation, silicon compound, cold emulsified emulsion is too dirty, NOF stage oxidation atmosphere and protective gas dew point is too high, air-fuel ratio is unreasonable, hydrogen flow rate is low, furnace aerobic infiltration, strip steel The temperature of the boiling pot is low, the pressure of the RWP section is low, the suction of the furnace door is low, the temperature of the NOF section is low, the oil is not evaporated, the aluminum content of the zinc pot is low, the speed of the unit is too fast, the reduction is insufficient, and the zinc liquid stays. The time is too short and the plating is too thick.we are provide galvanized iron wire,we can guarantee quality.