Views:1 Author:Site Editor Publish Time: 2021-06-30 Origin:Site
Corrosion of metals by residual ions in acidic water
According to statistics, the annual steel loss due to metal corrosion accounts for about 10-20% of the steel output that year. Indirect losses such as production shutdowns and power outages caused by metal corrosion accidents are even more incalculable. Corrosion of metals is very common. For example, iron products rust (Fe2O3·xH2O), white spots (Al2O3) appear on the surface of aluminum products, patina [Cu2(OH)2CO3] appears on the surface of copper products, and the surface of silverware turns black (Ag2S, Ag2O). The most commonly used metal-iron products, corrosion is the most common.
Pitting corrosion caused by chloride ions :
Pitting corrosion refers to the appearance of deep corrosion pores in the metal surface area, and the other areas are not corroded or corroded slightly. This type of corrosion is called pitting corrosion. Take steel as an example: the rapid increase of tiny "rust holes" on the surface of stainless steel is the cause of large-scale corrosion of stainless steel. A small change in the concentration or temperature of the corrosive material can significantly accelerate the corrosion rate. The rapid appearance of pitting corrosion is due to the rapid proliferation of meta-stable micropores on the metal surface.