Effects of Frequency and Stroke on Lubricated Reciprocating Friction between Plain Carbon Steel and Bearing Steel
Toku ITOH and Sadamu FUJII
Abstract:Effects of frequency and stroke on the running-in process were investigated on steels with an SRV tester by varying frequency and stroke under the same average velocity. A reciprocating bearing steel ball (SUJ2) was slid against a disc of plain carbon steel (S35C). As lubricant, paraffin base oil and DBDS (Dibenzyl Disulfide)-added oil were used. At higher frequency and smaller stroke the coefficient of friction fluctuated at the stage of initial friction but settled down to a steady friction in base oil. At lower frequency and larger stroke, the coefficient of friction continued to fluctuate, which resulted in a larger wear. The addition of DBDS significantly lowered the coefficient of friction independent of stroke. However, the wear was larger at lower frequency and larger stroke in DBDS-added oil. On the other hand, higher frequency increased the number of reciprocating contacts between specimens under a constant average velocity and it promoted the oxide film formation, which contributed to the decrease in wear. Key Words:Frequency, Stroke, Specific wear rate, Reciprocation, Coefficient of friction, Sliding velocity, Running-in, S35C, SUJ2, Wear debris