Passivation is not necessarily permanent and may need to be periodically reapplied to maintain the protective oxide layer on the surface of the metal.
Pickling pipe refers to the process of using acid solutions to remove scale and other contaminants from the surface of the pipe before further processing or use.
Carbon steel is often used over stainless steel because it is less expensive and more readily available, and may be suitable for certain applications where corrosion resistance is not a primary concern.
The hazards of passivation can include exposure to hazardous chemicals, such as nitric acid and hydrofluoric acid, as well as potential hazards associated with handling metal parts and equipment.
The thickness of steel passivation can vary depending on the specific process being used, but is typically in the range of 0.1-0.2 microns.