Application of Stainless Steel in the Nitric Acid Industry
Application of Stainless Steel in the Nitric Acid Industry
Stainless steel is widely used in the nitric acid industry due to its excellent corrosion resistance. It plays a key role in manufacturing equipment and devices for producing or handling nitric acid.
Materials Used in High-Pressure Processes
In high-pressure nitric acid production, the following stainless steel grades are commonly used:
- 00Cr19Ni10: Utilized in all absorption towers and ammonia-air mixers.
- 0Cr18Ni10Ti: Applied in various components.
- 0Cr18Ni11Nb: Used in exhaust gas burners.
- 0Cr25Ni20 (Nb): Also employed in exhaust gas burners.
- 1Cr17Ni2: Suitable for high-speed parts in gas compressors due to its martensitic properties.
Corrosion Resistance in Different Concentrations
- Azeotropic Nitric Acid (≨ 68.4%):
- Conventional 18-8 Cr-Ni austenitic stainless steel does not provide satisfactory corrosion resistance.
- Nitric Acid (≤ 85%):
- 0Cr25Ni20 stainless steel is preferred for this concentration range.
- High-Temperature or Concentrated Nitric Acid (with Cr+6):
- High-silicon austenitic stainless steels are used for enhanced corrosion resistance. Examples include:
- 1Cr17Ni11Si4AlTi
- 00Cr14Ni14Si4 (Ti)
- 00Cr17Ni14Si4 (Ti, Nb)
- Cr-Ni stainless steels with 5% to 6% silicon content are also effective.
- High-silicon austenitic stainless steels are used for enhanced corrosion resistance. Examples include:
Conclusion
The choice of stainless steel in the nitric acid industry depends on the concentration, temperature, and specific requirements of the application. Proper selection ensures durability and resistance to corrosion, enhancing operational efficiency.
