Precision seamless steel tube corrosion factors from TianyangSteelTube's blog
Compared with solid steel such as round steel, precision seamless steel tube
is lighter in weight under the same bending and torsional strength. It is economical steel and is widely used in the manufacture of structural and mechanical parts. Precision steel pipes have their own characteristics while inheriting the advantages of seamless steel pipes. Precision manufacturing of rings can improve the utilization rate of materials, simplify the manufacturing process, and save materials and processing time, such as rolling bearing rings, jacks, etc., which have been widely used in precision steel pipes. So what are the factors that cause the surface corrosion of Precision seamless steel tube?
1. Surface pollution: Oil, dust, acid, alkali, salt, etc. attached to the surface of the workpiece are converted into corrosive media under certain conditions, and chemically react with certain components in the stainless steel parts, resulting in chemical corrosion and rust.
2. Surface scratches: Various scratches destroy the passivation film, reduce the protective ability of stainless steel, and easily react with chemical media, resulting in chemical corrosion and rust.
3. Cleaning: After pickling and passivation, if the cleaning is not clean, the liquid will remain and directly corrode stainless steel (chemical corrosion).
Electrochemical corrosion1. Carbon steel pollution: The scratches and corrosive medium generated by contact with carbon steel parts form a primary battery, causing electrochemical corrosion.
2. Cutting: The adhesion of rusting substances such as cutting slag, splashes, and corrosive media forms a primary battery and produces electrochemical corrosion.
3. Baking: The composition and metallographic structure of the flame heating area change unevenly, forming a primary battery with the corrosive medium, causing electrochemical corrosion.
4. Welding: physical defects (undercut, pores, cracks, lack of fusion, incomplete penetration, etc.) and chemical defects (large grains, lack of chromium at grain boundaries, segregation, etc.) formed in the welding area and corrosive medium. Chemical corrosion of battery power generation.
5. Material: stainless steel
The chemical defects of the material (uneven composition, S, P impurities, etc.) and surface physical defects (looseness, blistering, cracks, etc.) are conducive to the formation of galvanic cells with corrosive media and cause electrochemical corrosion.
6. Passivation: poor pickling and passivation lead to uneven or thin passive film on the surface of stainless steel, which is prone to electrochemical corrosion.
7. Cleaning: The remaining pickling and passivation residues and chemical corrosion products of stainless steel will form electrochemical corrosion with stainless steel parts.
The above are the factors that cause the surface corrosion of Precision seamless steel tube, I hope to help everyone. Tianyang Steel Tube, as a Precision seamless steel tube enterprise, we provide Precision seamless steel tubes with long service life, welcome to consult and purchase.
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