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This post was last edited by Wang Wei2 on 2026-1-22 08:38. The corrosive environment is an objective factor that causes metal corrosion; it encompasses a wide range of complex elements, such as the composition and concentration of the medium, pH value, temperature, pressure, flow rate, the presence of harmful substances, as well as the amount of corrosion inhibitors, among others. These factors all have different effects on metal corrosion, with some even playing a decisive role. Therefore, controlling corrosion can also be achieved by improving the corrosive environment and reducing the corrosivity of the medium; depending on the situation, the following measures can be adopted. 1. Reducing the corrosiveness of the medium: The main methods for reducing the corrosiveness of a medium are removing harmful substances from it and adjusting its pH value. The corrosion of metals is the result of direct interaction between the metal and its surrounding environment, but not all substances in this environment have the same effect during the corrosion process. ***Some have a greater effect, some have a lesser effect, and some have no effect at all. Harmful components such as certain active ions (like Cl- ions) and dissolved chlorine play an important role. If these harmful components are removed, the corrosivity of the medium can be greatly reduced. For example: dissolved oxygen is one of the most common harmful impurities in water, and its presence can cause oxygen-depolarized corrosion of metals. Removing dissolved oxygen from boiler feed water is an effective measure to prevent boiler accidents. HCL is a harmful impurity present in the low-temperature areas at the top of distillation columns; its presence can cause the corrosion rate in such low-temperature systems to reach 10–20 mm/year, leading to severe corrosion of the column top, trays, vaporization lines, air coolers, and heat exchangers. Using process-based anti-corrosion methods to remove HCL is the most effective way to control corrosion. Corrosion can be controlled at 0.1~0.2 mm/a.