Scuffing behavior of gray iron and 1080 steel in reciprocating and rotational sliding

Scuffing damage is catastrophic and typically not self-healing. It severely affects the life and reliability of engineering components, such as cams, roller bearings, piston rings, cylinder bores and gears. Gray iron and 1080 steel are important materials for these extremely demanding structural components. There have been several scuffing studies done in the past with various types of steel and cast iron. However, in these studies there was no attempt to compare the scuffing resistance of cast iron and steel materials with similar matrices. In the present study, scuffing tests were performed with the matrices of gray iron and 1080 steel being fully pearlitic. This allows for a direct evaluation of the effect of the graphite flakes on scuffing resistance. The scuffing behavior for these materials was compared by two types of tests with different motion, i.e. reciprocation and rotation. The experiments were conducted using a high-frequency reciprocating rig and a ball-on-disc rotational rig at variable speeds. The load and the number of cycles for scuffing failure were measured. The results show that the scuffing initiation is due to crack propagation for gray iron and plastic deformation for 1080 steel. It is observed that 1080 steel exhibits higher scuffing resistance than gray iron in reciprocating sliding, whereas it is completely opposite in rotational sliding.