What is Stainless Steel?

Stainless steel is essentially a low carbon steel which contains chromium at 10% or more by weight. It is this addition of chromium that gives the steel its unique stainless, corrosion resisting properties.

The chromium content of the steel allows the formation of a rough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. If damaged mechanically or chemically, this film is self-healing, providing that oxygen, even in very small amounts, is present. The corrosion resistance and other useful properties of the steel are enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel and nitrogen.

There are more than 60 grades of stainless steel. However, the entire group can be divided into five classes. Each is identified by the alloying elements which affect their microstructure and for which each is named. The austenitic group (also referred to as the 300 series) is what this abstract will focus on, more specifically on grade 304/304L.

Cleaning stainless steel

Stainless Steel requires periodic cleaning just as other materials do when in service. For materials utilized in interior, light industrial or milder service, minimum maintenance is required. Finger marks, deposits from tobacco smoke, stains from hard water, or food left to dry on counter tops, all detract from the original attractive appearance.

Stainless used in exterior architectural building components is subject to road salt spray at ground level (similar to automotive applications) and deposits from polluted urban air at higher levels. Virtually all exterior applications utilize natural rainwater (or car washes) to perform an effective cleaning action. Only sheltered areas require additional washing with mild detergent and/or a stream of pressurized water wherever possible.