Sources of Nickel
Nickel is a wear metal found in some machines using plain bearings, as lead and tin are the most predominant metals used in Babbitt overlay, with lesser amounts of copper, antimony, and/or arsenic. Typically, increasing levels of nickel are from an intermediate layer and therefore considered actionable.
Nickel can also increase as wear from some steel parts. It will correlate with iron and other metals like chromium, titanium, molybdenum, and vanadium; if the correlation remains proportional as levels increase it suggests these metals are alloyed, but if the other metals increase disproportionally then this suggests coated steel parts.
One form of a harmless increase in nickel may be seen due to the use of a nickel-based anti-seize compound during reassembly, as any excess will dissolve into the oil as well.
Watch for the next article in the Elemental Spectroscopy blog series: Chromium
