Inhibition of Water-Accelerated Rolling-Contact Fatigue

Water in lubricating oils causes a significant reduction in rolling-contact fatigue life. This effect can be inhibited by lubricant additives that interfere with the mechanism by which water reduces fatigue life. Using a planetary four-ball machine, it is demonstrated that the addition of 0.1 percent isopropylaminoethanol completely counteracts the detrimental influence due to 1 percent seawater emulsified with the lubricant. It is suggested that the aminoalcohol condenses into surface microcracks along with water, captures hydrogen ions formed within the crack and thereby inhibits hydrogen embrittlement.