Abstract
The study was prompted by a desire to improve the wear resistance of power transmission components in rear axle drives on commercial farm tractors. Reciprocating wear tests were conducted under lubricated and non-lubricated conditions on three spheroidal cast irons which varied in strength and hardness (designated GGG450, GGG600, and GGG700). Hemispherically-tipped steel pins (designed 42CrMoS4/ 41CrS4) were used as the sliders. Except for the test duration, test procedures were similar to those described in ASTM Standard Test Method G133 for linearly-reciprocating sliding. Among the three cast irons tested, the harder and stronger the alloy, the lower was its wear rate. Wear factors were approximately four orders of magnitude lower for experiments lubricated in fresh, fully-formulated lubricating oil. There was a linear relationship between Brinell hardness of the alloys and the negative logarithm of the wear factors that were expressed in (mm3/N-m). Wear of lubricated test pins was not measurable due to the presence of deposits; however under non-lubricated sliding, the ratio of the wear of the flat specimen to that of the pin decreased as the hardness of the flat specimens approached that of the pin specimen.
