In 1913, while working on a project to improve rifle barrels, Harry Brearly accidentally discovered that after adding chromium to low carbon steel it becomes stain resistant. Stainless steel may also contain other elements, such as nickel, niobium, titanium and molybdenum. Molybdenum, niobium, nickel, and chromium enhance the corrosion resistance of stainless steel. Because of the addition of a minimum of 12% chromium to the steel it resists rust or stains. After the chromium combines with oxygen in the atmosphere it forms a thin, invisible layer of chrome-containing oxide, called the passive film. Due to chromium atoms and their oxides being similar in size, they pack neatly together on the surface of the metal, forming a stable layer only a few atoms thick. If the metal is scratched or cut and the passive film is disrupted, more oxide will quickly form and recover the exposed surface, protecting it from oxidative corrosion. Because passive film requires oxygen to self-repair, stainless steels have poor corr
osion resistance in low-oxygen and poor circulation environments. Also, chlorides from the salt will attack and destroy the passive film more quickly than it can be repaired in a low oxygen environment. There are three main types of stainless steels: austenitic, ferritic and martensitic. They identified by their microstructure or predominant crystal phase.
Stainless steel find use in a very wide variety of applications. Some typical examples are: kitchenware and tableware, kitchen sinks, laundry equipment and electrical and electronic appliances. Stainless steel also has been used in numerous famous buildings. Some of the common applications are balustrades, column wraps, roofing and guttering, curtain wall supports, signage, light poles, public seating and elevator doors. To extend the life of critical areas of roadways, marine structures and bridges stainless steel rebar is used. Stainless steel is also used for food and beverage production, storage, cooking and serving. Stainless steel also used for a large variety of applications in automotive. Exhaust systems, fasteners, trim, windscreen wiper arms, wheel covers, passenger railcars, coal wagons, bus frames and a lot more.
Stainless steel is one of the most hygienic surfaces for the preparation of foods and very easy to clean, as its unique surface has no pores or cracks to harbor dirt, grime or bacteria. It requires minimal care and very attractive, since it wont chip or easily rust and it takes little seasoning. Because it does not react with acidic foods during food preparation or cooking it will not affect flavor. With proper maintenance, it has a useful life expectancy of over 100 years, and it is totally recyclable.
There are few elements in stainless that have effects on our health. Iron can be very beneficial and a required mineral in a normal diet. Chromium is also beneficial in small quantities. Even though nickel is poisonous in large quantities, only trace amounts go into the food not enough to make a difference. However, the few who are allergic to nickel should avoid using stainless altogether.
Do not store food or liquids in stainless steel cookware after cooking. To keep the surface smooth and scratch-free, do not use abrasives, bleach or ammonia.