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Corrosion Protection
Chemical Treatment
Requirements
Passivation
Biological Control
Long Term Care of Stainless
Steel
Long Term Care of Stainless Steel
When the percentage of chromium in steel exceeds 10.5%, it is called stainless steel.
The chromium in the steel reacts with the oxygen in the air to form a chromium-oxide
surface layer, also called the passivation layer that provides the corrosion resistance in
stainless steel.
BAC’s Manufacturing Process
BAC takes precautions to prevent cross-contamination, processing galvanized and stainless
steel parts separately. Also, stainless steel brushes are used to clean welds on stainless
parts and care is taken to avoid scratching parts during processing. Organic cleaners are
used to clean the finished product prior to shipping.
Jobsite Considerations
While stainless steel itself does not rust so long as the chromium-oxide surface layer is
intact, it is not immune to contamination from its surroundings. Some common sources of
surface contamination are:
• Dirt and soil
• Shop oil or grease that may carry other contaminants such as metal chips
• Machining or welding galvanized steel at the jobsite may cause debris to impinge itself
into the stainless steel
These contaminants can deposit on the surface and scratch the passivation layer or
prevent it from re-forming. They can also get trapped underneath the passivation layer and
reduce corrosion resistance.
Recommended Cleaning Procedure
Stainless steel needs to be cleaned regularly to maintain the corrosion resistance as well
as to maintain the overall aesthetics of the stainless steel.
It is fairly simple to clean most contaminants off the surface of stainless steel. Most dirt
and soil can be cleaned with a clean cloth, warm water, and mild detergent. For persistent
dirt, a little vinegar can be added in the cleaning water. It is important to always rinse
the surface with warm water and wipe with a dry cloth after any cleaning, whether mild or
aggressive.
• Fingerprints, mild stains or grease spots can be cleaned using organic solvents such
as acetone, methyl or ethyl alcohol, or mineral spirits. Stainless steel wipes or glass
cleaners commonly available in stores may also be used.
• Occasionally the surface of stainless steel can get iron chips or shavings embedded
in it from having galvanized steel machined or welded in the vicinity. The iron chips
can start to rust, reducing the corrosion resistance of the stainless steel, and stain
the surface giving the impression that the stainless steel is rusting. These types of
contaminants require more aggressive cleaning. Mild abrasives such as Scotch-Brite™
products may be used where aesthetic considerations are not important followed by
solvent cleaning with organic solvents as described above. It is important to rinse the
surface with warm water and wipe with a dry cloth after cleaning.
NOTICE:
Never use chloride or
chlorine based solvents such as
bleach or muriatic (hydrochloric)
acid to clean stainless steel. It is
important to rinse the surface with
warm water and wipe with a dry
cloth after cleaning.
NOTE:
Long term care of stainless
steel information reprinted with
permission from “The Care and
Cleaning of Stainless Steel”;
Specialty Steel Industry of North
America; http://www.ssina.com.
