Corrosion resistance is the ability of the grease to prevent the metal in contact with it from being corroded. Shanghai Lubricants
Thickeners and base oils of greases do not corrode metals. There are many reasons for greases to be corrosive, mainly due to the oxidation of acidic substances.
Generally speaking, excessive free organic acids and alkalis will cause corrosion.
The corrosion test is to detect whether the grease has a corrosive effect on the metal. There are several methods for measurement, and the test conditions are different, but all are asked at a certain temperature and during the test, by observing the discoloration or speckle on the metal sheet. The extent of grease corrosion is not judged.
SH / T0331-92 "Grease Corrosion Test Method", using 100'C, 3h, copper and steel.
GB / T 7326-87 "Grease test of copper sheet of grease" stipulates the method for measuring the corrosiveness of grease on copper parts, using 100. C, 24h, copper sheet was measured, divided into A method and B method.
The first method is to compare the test pan with the standard color plate of the copper plate to determine the corrosion level; the second method is to check the test copper plate for discoloration. GB / T5018-85 "Grease Anticorrosiveness Test Method" specifies test methods for the anticorrosive performance of greases.
Method summary: The new bearing coated with the sample is run under a light thrust load for 60s to make the grease as plentiful as it is in use. The bearings were stored at 52'C ± l'C, 100X relative humidity for 48 hours, then cleaned and checked for signs of corrosion on the outer ring raceway of the bearing.
Corrosion in this method refers to any surface damage (including pitting, etching, rusting, etc.) or black stains on the outer ring raceway of the bearing.
This method can assess the ability of grease to prevent rust and other forms of corrosion of metals in contact with it under wet conditions.