Chrome burner	Stainless steel burner

Different types of steel used in patio heaters/burners can be seen by comparing chrome or tin plated burners with stainless steel burners.

How are stainless steel patio heaters

anti corrosive.

What is stainless steel used in patio heaters?

Stainless steel patio heaters contain chromium, or a combination of chromium/nickel, as well as amounts of other alloy additions such as molybdenum. Chromium content of a stainless steel patio heater is generally greater than 15 per cent, it is this alloy that keeps the patio heater's steel bright and rust resistant in spite of moisture or the action of corrosive acids and gases. Presence of nickel further improves the corrosion resistance of patio heaters as does molybdenum.

What are the types of grades of stainless steel?

The main requirement for use of stainless steel in patio heaters is that it should be corrosion resistant for the specified application and the environment the patio heater will be used in. The selection of a particular "type" and "grade" of stainless steel used in patio heaters must initially meet the corrosion resistance requirements. It is important to bear in mind that various grades of stainless steel will be used, some will be suitable in hotter climates whilst others would suffer from rust in a damp climate.  A stainless steel patio heater produced for the South African market would not be suitable in the UK.

Why is a stainless steel patio heater "stainless"?

The corrosion resistance of stainless steel in patio heaters arises from a "passive", chromium-rich, oxide film that forms naturally on the surface of the steel used in patio heaters. Although extremely thin at 1-5 nanometres (i.e. 1-5 x 10-9 metres) thick, this protective film is strongly adherent, and chemically stable (i.e. passive) under conditions which provide sufficient oxygen to the surface of the stainless steel patio heater.  Key to a stainless steel patio heater's durability of the corrosion resistance is that should the film become damaged it will self repair, provided sufficient oxygen is available. By contrast to other steels which suffer corrosion where areas of the surface are affected, stainless steel used in patio heaters are in the passive state and resistant to this form of attack.

Corrosion and oxidation resistance of stainless steel patio heaters

The corrosion/oxidation resistance within stainless steel patio heaters will improve as the chromium content increases. Additions of nickel to create the austenitic stainless steel grades will strengthen the oxide film to raises performance of stainless steel in certain conditions. Addition of molybdenum to either the ferritic or austenitic stainless steel patio heaters improves pitting corrosion resistance.