Stainless steel is a steel (an alloy of iron and carbon at less than 1.2 %) but with more than 10.5 of Chromium, the property of which is to be insensitive to corrosion and to avoid degradation in rust.
The presence of Chromium at more than 10.5% causes the formation of a protective layer of Chromium oxide wich gives the steel its stainless quality.
Stainless steel most often also contains Nickel in varying proportions which improves mechanical properties and ductility.
Stainless steel is often designated by the mass percentages of Chromium and Nickel. An 18/8 stainless steel or XxCrNi 18-8 is a stainless steel which contains 18% by mass of Chromium and 10% by mass of Nickel.
Some stainless steel grades contain Molybdenum or Titanium which improves the stability of the alloy at room temperature, or Vanadium and Tungsten to achieve resistance to high temperatures.
It should also be noted that depending on the grade, stainless steels are less magnetic than non-stainless steels.
Stainless steel is avaialble in spring and non spring grades. Filame works both types.
Stainless steel is used in most industrial sectors. It si fully recyclable. Its price depends in particular on what is called the alloy extra, i.e the amount of Chromium and Nickel that is added to the steel and which represents between 50 and 70 % of the price of the matierial, depending on the grade.
The various grades of stainless steel commonly used are as follows :
- Stainless steel AISI 430 or X8Cr17 to 18 or 1,4016. It is a stainless steel which allows easy stamping. It is used in particular for household items, appliances, sinks, … It is mainly presented in sheets (sheet or coil). It is a stainless steel that is easily welded. Thas is a grade that is frequently used by Evinox (evinox.be), a subisdiary of Filame, which is active in articles for catering, brewery and camping/caravaning sectors.
- Stainless steel AISI 304 or X5CrNi18-10 or 1.4301 stainless steel (or its 304L stainless steel variant X2CrNi18-09 – 1.4307) is the most common stainless steel for all types of parts in all sectors. It is a stainless steel that is easily cut and formed by bending or stamping. It is a stainless steel that is easily welded. It does not have spring quality and therefore cannot be used for spring clips or spring blades. Stainless steel 304 comes either in sheets (sheet metal or coils) or wire. Filame uses this type of stainless steel both in sheet and wire.
- Stainless steel AISI 301 (for flat products) or AISI 302 (for wire products) or X10CrNi18-8 of 1.4310 is the spring quality stainless steel which is used for spring laldes, spring clips and for all types of springs made out of wire. The mechanical strengths of these stypes of stainless steel is greater that stainless steel 304. It starts at Rm 900 and eventually goes ou to Rm 1700. The most widely used grades for flat parts are Rm 1100-1300 and Rm 1300-1500. Unlike hardenable steels, spring stainless steel must not be hardened but must undergo a stress relief annealing at a minimum of 310° to give its full spring quality. These are also stainless steels may be cut and formed through bending or stamping, although it is necessary to take into account their greater hardness than stainless steel 304 in this regard (to avoid cracking). Filame is specifically specialized in 301 or 302 stainless steel spring parts.
- Stainless steel AISI 316 or X5CrNiMo18-10 or 1.4401 is a stainless steel more resistant to corrosion. It is the so-called food grade stainless steel due its corrosion resistance. Like AISI 304 stainless steel, it can be cut, bent or stamped. It comes in the form of sheets (sheet metal or coils) or wire. It may or may not have spring quality. This is a nuance frequently used by Filame.
- Stainless steel AISI 316L or X2CrNiMo17-12-02 or 1.4404 is a stainlesss telle with high corrosion resistance (higher than AISI 316). It is used in particular for marine, medical and phamaceutical applicatins. It has the same properties as stainless steel 316 and it also avialble is sheet, coils and wire. Filame regularly uses this nuance for tis pharmaceutical customers.
- Duplex stainless steels (in particular X2CrNiMoN 22-5-3 of 1.4462) are a category of stainless steels which have better mechanical charccteristics and resistance to corrosion than the above grades. They are used in thechemical and marine industries. It is notably known under its brand Springflex from Sandvik (for wire)
- Stainless steel 17/7 ph or X7CrNiAl17-7 or 1.4568 is a hardened stainless steel. It provides high strength and hardness, excellent fatigue properties and good corrosion resistance. It can be in the form of sheet or wire. It is used in particular in the aeronautic industry. Filame works this shade exclusively in the form of wire.