Nowadays, it is very easy to reach stainless steels in many different and easily accessible qualities and surface properties, working without problems in difficult environmental conditions during product’s life.Even in our normal daily life, we can see that these products are extensively used from flatwares to the watches.
Stainless steel is highly resistant to corrosion and oxidation in many natural and man-made environments. But for every particular application, it is very important to choose the correct quality and type of stainless steel.The first step in quality selection begins with a detailed analysis and identification of all the possible and present working conditions to which the stainless steel will be exposed during the design phase. High oxidation resistance is achieved by adding a minimum of 13% (by weight) of chromium at normal room temperature and weather conditions, and up to 30% in very hard and difficult environmental conditions.
When the chromium in stainless steel is exposed to oxygen (in the normal atmosphere), it immediately forms a chromium oxide (Cr2O3) passivation layer. This layer is so imperceptibly thin that it protects the metal it covers, completely obstructing the penetration of water, any gas and oxygen into the stainless steel. In addition, the gap that will be created if this layer is torn, opened or scratched for any reason is quickly formed again by restoring the layer itself very quickly. This is called passivation and is also seen in some other metals such as titanium.
The nickel element also contributes to the passivation just like molybdenum and vanadium elements used in low ratios do. The resistance to corrosion and staining of the stainless steel makes it an ideal and indispensable material because it has wide commercial application, low maintenance cost, spectacular appearance, and it is cheaper in comparison with others. Though there are over 150 stainless steel qualities in total, 15 of these are commonly used and very popular on the market. Stainless steels, like other steels, are widely used as cold and hot rolling methods and casting parts in many ways such as flat products, plates, rods, wires, pipes, shaped long products, in many areas such as food industry, medicine, surgical equipments, industrial equipments, automotive, white goods, construction and construction elements, buildings. One of the areas where stainless steel is used is the products we always keep with us in our everyday life, like jewelry and watches. The most common quality used in jewelry is 316L. Stainless steel does not oxidize and darken over time like silver does. In addition, the stainless steel density is slightly lighter than silver, providing convenience for designers.
STAINLESS STEEL