Stainless steels are widely used for their oxidation
resistance at elevated temperatures. In air, a protective
scale is formed which is generally quite stable up to
about 800-850°C unless substantial cycling of temperature
occurs. Some steels resist scaling at even higher temperatures.
Special
Considerations for High Temperature Service:
Water vapour and sulphur dioxide, if present, can accelerate
oxidation rates of stainless steels. Hydrogen sulphide
and sulphur vapours are more aggressive to stainless
steels than oxygen and substantially reduce the maximum
allowable temperature in air.
Thermal Cycling
Oxidation Resistance:
Weight change: grams per square metre of surface for
temperatures as shown:
These were cyclic tests for 100 hours duration in air
containing 10% water vapour. Cycled every 2 hours to
room temperature then back to test temperature. Weight
gain or loss (-), measured
without purposeful removal of scale.
Some of the higher temperature tests, indicated by *,
were for a much shorter time than the 100 hours.
