Before pickling and passivation, the tube and tube heat exchanger is cleaned before pickling. In fact, pickling provides a major prerequisite for post-passivation to make the post-passivation film complete and stable. Passivation is usually carried out with oxidizing agents. Different passivation treatments will directly affect the composition and structure of stainless steel.
1, pickling and passivation purposes:
Tube and tube heat exchangerPickled and passivated to remove dirt such as oil, rust, scale and solder joints. After treatment, the surface is uniform silver-white, which greatly improves the corrosion resistance of stainless steel. Suitable for all types of stainless steel parts, plates and equipment.
2, Pickling and passivation characteristics:
It has the advantages of simple operation, convenient use, economy and practicality. At the same time, corrosion inhibitors and anti-fogging agents are added to prevent excessive metal corrosion and hydrogen embrittlement, reduce the generation of acid mist, and are suitable for small and complex workpieces.
3, pickling and passivation use:
Depending on the material of the tube heat exchanger and the severity of scaling, reserve liquid or water can be used to1:1~4The austenitic stainless steel with low ferrite, martensite and nickel content is diluted and used, while the austenitic stainless steel with high nickel content is soaked in the stock solution; generally at room temperature or heated to50~60Use after use. soak3-20Minutes or longer until the surface dirt is clean and turns into a uniform silvery white color, and a uniform and dense passivation film is formed, then take it out and rinse with clean water. Try to rinse with alkaline water or lime water.