Stainless steel delivers wide-ranging benefits in any application. A generic term for alloy steels containing 10.5% or more chromium, stainless steel gets its protection from the naturally occurring chromium-rich oxide film, which forms an invisible layer on its surface to prevent corrosion and oxidation. Stainless steel products also have a long lifecycle and are 100% recyclable.
With over 150 grades of stainless steel, it’s important to understand the ‘type’ and ‘grade’ of stainless steel to ensure its suitability for any particular application.
Grab rails from Con-Serv Corporation Australia are all fabricated from 304, 18/8 stainless steel due to its strength, flexibility and resistance to corrosion.
Alloy types
An alloy type such as 304 is the basic chromium-nickel austenitic stainless steel with a minimum of 18% chromium and 8% nickel, combined with a maximum of 0.08% carbon. Easy to form and fabricate, this stainless steel grade is also corrosion-resistant, making it suitable for a wide range of applications.
Alloy grade 304L is the low carbon version of 304, the letter ‘L’ after the grade number indicating that the carbon content is restricted to a maximum of 0.03%. Low carbon stainless steel is ideal for applications where welding is performed, helping prevent the chromium from being depleted so it can form the protective oxide layer.
Alloy grade 316 incorporates molybdenum, adding to its corrosion resistance. This grade is ideal for environments susceptible to severe corrosion such as marine locations. 316L is the low carbon version of 316.
What is 18/8?
The first number, 18 refers to the amount of chromium in the stainless steel while the second number, 8 is the amount of nickel. Therefore, 18/8 indicates 18% chromium and 8% nickel, and is part of the 300 series grade family, which is non-magnetic.
Caring for stainless steel
To ensure your stainless steel product remains corrosion-resistant, the surfaces must be cleaned and have an adequate supply of oxygen to maintain their ‘passive’ surface layer. Created when oxygen combines with chromium in the stainless steel to form chromium oxide, this passive film is invisible on the surface.
The quality of stainless steel is an important factor when it comes to corrosion resistance. Stainless steel products supplied by reputable manufacturers or fabricators will normally be clean and contamination-free. Generally, stubborn stains and discolouration occur when there is an overall breakdown of the passive film due to incorrect cleaning procedures. Rust stains from corrosion will be visible as a slight brown stain on the surface to severe surface pitting or rusty scour marks. By keeping stainless steel surfaces clean, corrosion resistance can be maximised.
Cleaning stainless steel
The basic rule to cleaning stainless steel products and surfaces is to begin with the mildest method. Alkali cleaners such as baking soda or ammonia are effective on stainless steel. You can use soap, mild detergents or an ammonia solution in warm water applied with a soft cloth or nylon sponge for polished finishes, and then rinsed with clean water and dry-wiped to eliminate any water stains. A nylon scouring pad may be required for satin finishes.
Things to avoid when cleaning stainless steel
Ordinary steel wool must be avoided as iron particles can become embedded in the stainless steel and cause contamination.
Do not use chlorides or acids as they are reactive to stainless steel. Strong acid solutions such as hydrochloric acid or spirits of salts are sometimes used to clean masonry and tiling of new bathrooms and toilets, but they should never come into contact with any metal including stainless steel.
Brick cleaning liquids containing hydrochloric acid should also be avoided. Many cleaning solutions and solvents contain chlorinated hydrocarbons. If a cleaner contains chloride, bleach and hypochlorite, it must be promptly and thoroughly cleaned off.
Please note: The Con-Serv warranty on grab rails will be null and void should they be exposed to chemical corrosion due to poor cleaning practices.
