Why does the stainless steel pipe rust and corrode?

Many people think that stainless steel pipes will definitely not rust, which is a wrong one-sided view. First, the stainless steel tube's rust and corrosion resistance are conditional. The stainless steel pipe is a steel pipe that does not produce rust in a weak corrosive environment such as the atmosphere or fresh water, and the chromium content in the steel must be ≥12%. If the chromium content is low or not in a weakly corrosive environment such as the atmosphere (including in a weakly corrosive environment such as the atmosphere, but under the condition of Cl-local rich enrichment), rust will be produced. Acid-resistant steel pipes are steel pipes that are resistant to corrosion in strong corrosive media such as acid, alkali, salt, etc., but they are also resistant to corrosion under certain conditions, such as medium type, temperature, concentration, impurity content, flow rate, pressure, etc. There are no stainless steel pipes in the world that are not rusted or corroded under any conditions.

Because of this, we must choose and use stainless steel pipes properly. The correct choice is to select the stainless steel tube according to the requirements of the specific conditions of use. Reasonable use is to make reasonable use of the stainless steel tube's stainless and corrosion resistance. Choosing the wrong or unreasonable use can cause the stainless steel tube to rust and corrode. Problems with the quality of the stainless steel tube can also cause rust and corrosion of the stainless steel tube. Therefore, the quality of stainless steel pipes is a prerequisite for the correct selection and rational use of stainless steel pipes.

Stainless steel tube corrosion is simply a damage and failure caused by chemical and electrochemical interaction between the stainless steel tube and the corrosive medium. Classified according to the nature of corrosion, it can be divided into chemical corrosion (corrosion in non-electrolyte solution, such as oxidation of stainless steel tube at high temperature) and electrochemical corrosion: steel and stainless steel tubes in humid atmosphere, aqueous solution and acid, alkali salt Corrosion generated in the electrolyte solution, ions (electrons) are generated during the etching process. The essence of electrochemical corrosion is the role of the primary battery.