Sign dry corrosion Generally refers to corrosion that occurs in high temperature gas, and common is high temperature oxidation. In high-temperature gas, an oxide film occurs on the metal surface, and the nature of the film and the growth rules determine the corrosion resistance of the metal. The growth rules of the film can be divided into straight rules, parabolic rules, and logarithmic rules. The straight-line oxidation is the most dangerous, because the weight loss of the metal increases at a constant rate with time. The rule of parabola and logarithm is that the oxidation rate drops with increasing film thickness, which is safer. For example, aluminum oxidizes at normal temperature and follows the logarithmic rule. The film growth is stopped after a few days, so it has outstanding resistance to atmospheric oxidation. The shape of corrosion can be divided into two types: uniform corrosion and partial corrosion.