The practical significance of hot dip galvanizing of galvanized sheet depends on that the corrosion resistance of hot rolled strip steel is greatly improved after the surface layer of hot dip galvanizing is covered, which can save raw materials and resources and give full play to the excellent economic benefits and natural environmental benefits.
The key to the maintenance efficacy of hot dip galvanizing layer of galvanized sheet for hot rolled strip steel is as follows:
(1) when the thick steel plate surface intact, only zinc corrosion, because the zinc corrosion material has a good maintenance effect, so the corrosion rate is very slow, the service life will be 15-30 times of galvanized steel plate.
(2) the most common situation is galvanized sheet in production and processing, installation, application, surface scratches, or any other reason the layer under the part damaged, hot rolled strip steel exposed from the wound in the natural environment, if be the chemicals of non-metallic materials, exposed blocks will be etched away, but the maintenance characteristics of cold rolled steel sheet unique, make etching rate is slow, in this way The zinc in the coating and the iron in the hot rolled strip steel constitute a galvanic cell in the wet and cold environment, because the standard electrode potential of zinc is only -1.05V, less than -0.036V of iron, so zinc as an anodic oxidation by air oxidation, and iron as a negative plate to obtain maintenance. Because the products after zinc are very high density, the reaction time is relatively slow, in other words, the overall corrosion resistance is greatly improved. This kind of prevention method is called corrosion resistance.
Post time: Dec-22-2021