-
The necessity of stainless steel pickling passivation
Austenitic stainless steel has good corrosion resistance and high temperature oxidation resistance properties, good low temperature performance and excellent mechanical and processing properties. Therefore, it is widely used in chemical, petroleum, power, nuclear engineering, aerospace, marine, pharmaceutical, light industry, textile and other sectors. Its main purpose is to prevent corrosion and rust. The corrosion resistance of stainless steel mainly depends on the surface passivation film. If the film is incomplete or defective, the stainless steel will still be corroded. In engineering, pickling and passivation treatment is usually carried out to make the corrosion resistance potential of stainless steel play a greater role. In the process of forming, assembling, welding, welding seam inspection (such as flaw detection, pressure test) and construction marking of stainless steel equipment and components, surface oil stains, rust, non-metallic dirt, low melting point metal contaminants, paint, and welding Slag and spatter, etc., these substances affect the surface…
-
Oxidation Resistance of Stainless Steels
Oxidation is the formation of oxide rich scale. The scale, once formed, slows down further oxidation, unless it is mechanically removed or cracked, which can happen if the steel deforms under load. In stainless steel, used at elevated temperature up to 1100°C for heat resisting types, this is used to advantage, the scale formed being predominantly chromium rich. The reformed scale layer will prevent further oxidation, but the metal lost in the formation of oxide will reduce the effective strength of the steel section. Oxidation resistance depends mainly on temperature, gas composition and moisture level and steel grade mainly chromium level. Austenitic stainless steel are the best choice as they also have better elevated temperature strength than the ferritic family. The higher thermal expansion rates of the austenitics can result in problems such as distortion and may lead to scale loss (spalling) during thermal cycling. Conditions for stable oxide formationOxidation is dependent mainly on the oxygen…
-
Corrosion
Articles on corrosion resistance research, how to choose materials for different corrosion environments. Corrosion resistance studies of different materials. Corrosion Catagory 1. Calculation of Pitting Resistance Equivalent Numbers PREN 2. Stainless Steel Selection Avoid Localised Forms of Corrosion 3. Designing Stainless Steel Handrails and Balustrades 4. Fatigue Properties and Endurance Limits of Stainless Steel 5. Corrosion Resistant Agitators Stirrers and Mixers 6. Copper Nickel Seawater Corrosion Resistance and Antifouling 7. Copper and Copper Based Alloy Corrosion 8. Effects of Copper Alloy Chemical Compositions on Corrosion 9. Corrosion Problem – Process and Cost of Metallic Corrosion 10. Fundamental of Metal Corrosion 11. Corrosion Resistance of Nickel Alloys 12. Corrosion Resistance of Titanium 13. Corrosion Resistance of Zirconium 14. Corrosion Resistance of Tantalum 15. Corrosion by Material and Media 16. Liquid Molten Metal Corrosion Resistance of Stainless Steel 17. Sulphidation Resistance of Stainless Steel 18. Preventing Corrosion in Cooling System 19. Preventing Erosion-Corrosion in Cooling Systems 20. Grain Size 21. Grain Size Scale 22. Different Measures of Grain Size 23. The International Scene of Grain…