Wear and corrosion protection in roller bearings – Influence of ratio between extreme pressure / anti wear additive and corrosion inhibitor

Roller bearings are lubricated with oils or greases containing several additives to reduce wear and corrosion. Given that almost 50% of bearing failures arise from abrasive/adhesive wear and moisture-induced corrosion, the combined role of EP/AW additives and corrosion inhibitors (CIs) is crucial. However, their polar nature indicates potential antagonism when CIs are combined with EP/AW-containing oils. The impact of simultaneous EP/AW and CI use on corrosion resistance remains unknown. This study presents a novel corrosion protection test to evaluate this interaction. Furthermore, studies on other additive combination demonstrate the importance of the ratio between additives for optimum functionality. Therefore, the effect of the CI ratio to EP/AW on wear and corrosion protection is also being studied. The results clearly recommend the addition of 0.5 wt% CI when using 1.0 wt% EP/AW in order to achieve a good compromise between wear and corrosion protection.