Because the carbon content of stainless steel pipe is very low, there will be no carbide precipitation under the condition of general heat treatment and welding. This eliminates the risk of intergranular corrosion after general heat treatment and welding. Due to the high chromium nickel molybdenum content and the addition of copper, stainless steel can be passivated even in reducing environments, such as sulfuric acid and formic acid. High nickel content makes it have low corrosion rate in active state. In the concentration range of 0 ~ 98% pure sulfuric acid, the service temperature of stainless steel can be as high as 40 ℃. The corrosion resistance of pure phosphoric acid in the concentration range of 0 ~ 85% is very good. In the industrial phosphoric acid produced by wet process, impurities have a strong influence on the corrosion resistance. In all kinds of phosphoric acid, the corrosion resistance of stainless steel is better than that of ordinary stainless steel. In strong oxidizing nitric acid, the corrosion resistance of stainless steel pipe is lower than that of high alloying steel without molybdenum.

In hydrochloric acid, the use of stainless steel is limited to a lower concentration of 1-2%. In this concentration range. The corrosion resistance of stainless steel is better than that of conventional stainless steel. Stainless steel has high resistance to pitting corrosion. In chloride solution, its anti crevice corrosion ability is also very good. The high nickel content of L stainless steel reduces the corrosion rate in pits and gaps. When the temperature of ordinary austenitic stainless steel is higher than 60 ℃, it may be sensitive to stress corrosion in a chloride rich environment. This sensitivity can be reduced by increasing the nickel content of stainless steel. Due to the high nickel content, stainless steel has high resistance to stress corrosion cracking in chloride solution, concentrated hydroxide solution and hydrogen sulfide rich environment.