How Austenitic Steels Is Magnetics?

Today we want to deal with a very complex subject. The magnetism in the austenitic steels.

Austenitic steels. Why they become magnetic?

The type of austenitic steels contains Cr (16 – 20%), Ni (7 – 18%) and only some kind of types, also Mo (2 – 6%) with a carbon content of typically less than 0.08%. The presence of stabilizing elements (such as Ti, for example) improves the corrosion resistance, particularly intergranular. At the same time it provides an increased resistance to high temperatures.

This type of steel is characterized by a stable austenitic structure at any temperature. After a heat treatment it does not show any increase of mechanical strength. But how is it possible to increase mechanical resistance? With added nitrogen, or by cold deformation processes (example: rolling, drawing, molding, extrusion etc.) able to “work-hardened” the material. Thereby increasing its hardness andintroducing a magnetism. (more or less pronounced)

A1 X8CrNiS18-9 steel 1.4305 303

A high content of sulfur in the stainless steel austenitic:

Ensuring a better workability
A non-optimal corrosion resistance (works only in the atmosphere, to food substances and organic type chemicals)

The mechanical strength, however, can be increased by means of cold deformation. This type of steel, also, is not weldable. It is mainly used for machined on high-speed automatic machines. (eg. pins, bushings, screws, nuts, bolts, turnbuckles etc ..)

Magnetism. How is it transmitted?

The processes mentioned above such as rolling, drawing, molding or extrusion etc .. are fundamental for the production of screws and bolts stainless. In particular, during the molding of the washers is transmitted a strong magnetism.

To make the process possible some articles with small dimensions (eg. plugs) are manufactured specifically for A1 steel.