Coatings protect bearings from corrosion and wear

Citation

(2006), "Coatings protect bearings from corrosion and wear", Anti-Corrosion Methods and Materials, Vol. 53 No. 2. https://doi.org/10.1108/acmm.2006.12853bad.003

Coatings protect bearings from corrosion and wear

Coatings protect bearings from corrosion and wear

Keywords: Coatings technology, Corrosion

INA has launched a range of coatings that are designed to improve performance and protect bearings from corrosion, wear, friction and slippage.

INA and FAG standard bearings are premium products that guarantee the user optimum performance and a long service life. However, in some operating conditions, standard designs may reach their limits and in these cases coatings can help to improve the bearing's service life.

Coatings are applied to the surfaces of rolling bearing components without forming a material bond, for example, by diffusion, between the coating and base material.

In many cases it is sufficient to coat only part of the bearing or one of the partners in rolling contact.

INA FAG can advise customers when a coating may be appropriate and what type should be used in particular applications.

Protection from corrosion and fretting corrosion INA FAG has developed a range of coatings to protect bearings from corrosion and fretting corrosion including zinc iron coatings for rolling mill applications, zinc nickel for bearings used in automotive engineering and zinc phosphate for applications exposed to seawater.

Corrotect zinc iron coatings are ideal for small bearings and bearing mating parts that need to have a greater resistance to corrosion, for example, drawn cup needle roller bearings with open ends, thin walled components in large numbers.

A chemical nickel coating is also available to protect bearing housings and is ideally suited for applications within the food industry.

Protection from wear, friction and slippage, INA FAG also offers a wide range of coatings to protect bearings against wear, friction and slippage.

These include a black oxidising coating, which is ideally suited to rollers and rings for bearings in wind turbines and rail traction motor bearings.

It is also ideally suited to applications which may have a minor risk of slippage.

Thin dense chromium coatings (TDC) also offer effective wear protection in mixed-friction conditions for small ball and roller bearings and is suitable for raceways of high precision bearings and spindle bearings.

A copper coating is also available for emergency lubricant on bearing cages, whilst silver coatings are used for the same purpose on aerospace bearings and titanium nitride offers the user wear protection in jet engine bearings.

Prevention of current passage rolling bearings are electrically insulated to prevent passage of electric current.

The ODs and the faces, or alternatively the bore and the faces, are then coated with aluminium oxide.

FAG offers two different coating thickness: thick insulating coating with a high resistance to prevent current passage even in moist environments; or alternatively a thin insulating coating with a low resistance to current passage.

This coating has sturdier edges due to the lower coating thickness.

A thick coating of aluminium oxide is ideally suited for applications involving three-phase motors and traction motors, whilst a thin coating is ideally suited for applications involving traction motor bearings and tapered bearings for axle bones.