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1. Principle. Because zinc does not change easily in dry air, and in humid air, the surface can form a very dense film of zinc carbonate, which can effectively protect the interior from corrosion. And when the coating is damaged for some reason and the matrix is not too large, the zinc and steel matrix form a micro cell, so that the fastener matrix becomes the cathode and is protected. It is widely used in automobile transportation and other industries, but what is needed is the trivalent chromium passivation layer, zinc nickel alloy plating closed coating, reduce the harmful and toxic layer of hexavalent chromium passivation.

In the purchase of large rolls of galvanized wire, see the hardness of galvanized wire first, only after the hardness reaches the standard can be used. The hardness standard of large roll galvanized wire is a very important performance index and an economic test method. But for the hardness of metal materials, there is not a unified and clear definition including all test methods at home and abroad.