What to do if 316L thick-walled stainless steel pipes corrode

Because 316L thick-walled stainless steel pipes are corrosion-resistant, impact-resistant, and high-temperature resistant, they are commonly used in pharmaceuticals, chemicals, food, light industry, chemical machinery, industrial pipelines, and mechanical parts. Of course, 316L thick-walled stainless steel pipes are also suitable for the production and manufacturing of exhaust pipes and various basic pipelines. However, corrosion may occur in 316L thick-walled stainless steel pipes after a period of use. So, what should be done if 316L thick-walled stainless steel pipes corrode?

We know that when 316L thick-walled stainless steel pipes are corroded by thermocouples, the anodic oxidation is destroyed, and the negative electrode is protected. If we try to keep the 316L thick-walled stainless steel pipe as a negative electrode from beginning to end, then the steel pipe will not easily corrode. This anti-corrosion method for 316L thick-walled stainless steel pipes is called pipeline cathodic protection. This is also a way to protect 316L thick-walled stainless steel pipes. 316L thick-walled stainless steel pipes not only use movable metal materials as a protective film, but also destroy movable metal materials to protect metal components. Further scientific research can also be conducted to perform anodizing without destroying the original anodizing process. Therefore, cathodic protection methods can be divided into protective film methods and electrical equipment protection methods.

Using a relatively active alloy as a protective film, it is inserted into the surface of the 316L stainless steel welded pipe, or connected to the protective metal material with a transmission line, making the protective film and the protective metal material the two sides of a galvanic cell reaction. Since the protective film of the 316L thick-walled stainless steel pipe is an active metal material, it has an anodizing effect in the cell. It is damaged by corrosion and oxidation in the air. The protective alloy acts as the negative electrode, and the original small rechargeable battery terminates or weakens at the negative electrode, then the protective metal material component is damaged. When the protective film is about to rust, it can be replaced with another protective film.

Therefore, this method of corrosion protection for 316L thick-walled stainless steel pipes is a protective method, also known as cathodic protection. For example, there are zinc blocks in gas-fired steam boilers, and zinc is often embedded around ship propellers and aircraft propellers. Zinc is more reactive than iron, so zinc slowly corrodes and protects the heating furnace and aircraft propellers. During electrolysis, the electrode connected to the negative terminal of the switching power supply is less likely to be damaged. In this electrode configuration, electronic devices are unnecessary, so the negative electrode itself cannot lose its electronic components and become a positive electrode.

In other words, the negative electrode is not easily damaged. Based on this principle, we can use an external current to connect the 316L thick-walled stainless steel pipe to the negative connection of the switching power supply, and set the positive terminals of the auxiliary power supply and the switching power supply as the anodizing connection, then maintain the negative electrode. Anodizing can be applied to wastewater pipes, old train tracks, etc., where corrosion occurs slowly under low conditions. This method is similar to a protective film method.