Hydrogen sulfide leads to an insignificant increase in the corrosion rate of the arc-sprayed aluminum coating both in a chloride–acetate solution and in model seawater. The insoluble corrosion product of zinc, namely, its sulfide, does not passivate these coatings. The saturation of model seawater with hydrogen sulfide decreases the corrosion rate of 20 steel by a factor of ∼ 7 and the corrosion rate of the hot-dip zinc coating by a factor of ∼ 1.4 but does not affect the corrosion rate of the arc-sprayed coating. For the hot-dip zinc coatings, hydrogen sulfide does not change the corrosion rate, whereas for the arc-sprayed coatings, it decreases the corrosion rate by a factor of ∼ 5. It is shown that, in chloride–acetate solutions, hydrogen sulfide promotes an increase in the corrosion rate of 20 steel by more than an order of magnitude. This is why galvanized steel has been in use for the last 2,000 years, and why it’s probably going to be okay in your application.We study the corrosion of a hot-dip zinc coating and arc-sprayed aluminum and zinc coatings in chloride- acetate solutions and model seawater saturated with hydrogen sulfide. In fact, slow enough that it’s usually not a problem. So does galvanized steel rust? The answer is yes, but very slowly. Low temperatures have no effect on a galvanized coating. It is however an accelerating factor when combined with corrosive factors like humidity and industrial pollution. High temperature alone won’t break down zinc, providing it’s below the melting point of 787☏ (420☌). However, the size of the impact depends very much on the type of soil and overall conditions, (muddy and wet or sandy and dry.) Burying galvanized steel in soil, (as the base of a fence post for example,) will expose it to more moisture. High or low humidity, exposure to salt, acids or industrial pollutants. When you’re thinking about using galvanized steel it is important to consider what the local conditions will be like.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |