The corrosion resistance of stainless steels usually depends on the carbon content as well as on the proportions of chrome, molybdenum and nickel contained in alloys.
Stainless steel shafts that are suitable for the use of ball bearings or rolling bearings must have hardened surfaces in order to ensure that the balls do not create grooves. These types of steel (e.g. 1.4034, 1.4112, 1.4125) have a comparatively high C content (over 0.5%) in order to be hardenable. They are only corrosion-resistant to a very limited extent.
The highest corrosion resistance is found in stainless steels with low carbon content and a chromium content of more than 17 percent. Even additives such as nickel or molybdenum are unable to enhance this corrosion resistance. As these austenitic materials (e.g. 1.4301, 1.4305, 1.4571, 1.4404) cannot be hardened, they are not suitable for use with recirculating ball bearing guides. They are suitable for use with plastic plain bearings, in contrast, and this suitability in respect of service life can even be calculated.
The combination of highly alloyed stainless steel (e.g. 1.4571) with a high-performance polymer (e.g. iglidur® X) can thus be described as resistant even when it comes into contact with seawater. An ideal combination in cleaning-intensive industries, in filling equipment, in the chemicals and electroplating industries.