Stainless steel

Stainless steels are used since almost 100 years ago in areas in which corrosion plays an important role.

When the chromium content is higher than 10, 5% then we can talk of stainless steels. Additional contributions to the alloy such as nickel, molybdenum, niobium and titanium help to improve its resistance to corrosion and increase its mechanical strength results.

The chromium’s resistance to corrosion is based on a passive layer which forms itself on the surface. It is important that this approximately 0,00001 mm thick protective layer is not damaged by any scratch or ferritic corrosion germ, as well as by scaling or any combustion.

Therefore in the stainless steel processing it has to be consistently ensured that such damages will be avoided or removed from the deepest pore. It is especially important to ensure that, even before starting the stainless steel processing, there will be separate spaces, steel-free welding and working tables and separate tools and clamping accessories available and different from those for the steel processing.

Working and welding tables made of an aluminum-copper alloy offer in the following areas the safest basis for the professional work with stainless steel:

    The chromium’s resistance to corrosion is based on a passive layer which forms itself on the surface. It is important that this approximately 0,00001 mm thick protective layer is not damaged by any scratch or ferritic corrosion germ, as well as by scaling or any combustion.

    Therefore in the stainless steel processing it has to be consistently ensured that such damages will be avoided or removed from the deepest pore. It is especially important to ensure that, even before starting the stainless steel processing, there will be separate spaces, steel-free welding and working tables and separate tools and clamping accessories available and different from those for the steel processing.

    Working and welding tables made of an aluminum-copper alloy offer in the following areas the safest basis for the professional work with stainless steel:

    • Stainless steel - pipes
    • Stainless steel - railings
    • Stainless steel - containers
    • Stainless steel - fire places
    • Stainless steel - furniture
    • Stainless steel – fences

    The manufacturers of stainless steel plates and profiles should also try to cover the surface of their products with a film in order to protect them for their transport.

    Stainless steels vary from ferritic steel to austenitic stainless steel depending on their alloy components.

    All stainless steels are more or less prone to:

    • Surface corrosion favored by mechanical or chemical surface erosion.
    • Intergranular corrosion in stainless steels with a carbon content higher than 0.03%, and mainly in the welding area.
    • Pitting corrosion due to damages caused by ferritic scratches and germs, as well as by the adhesion of rust and scaling to the passive layer.
    • Crevice corrosion. Crevices in the parts are to be avoided.
    • Contact corrosion when touching any other metal such as an electrolyte.
    • Stress corrosion in the construction industry, at high temperatures and tensile stress.

    More interesting subjects about welding can be found under: