On Scuffing Conditions under Rolling/Sliding Contact : Part 2 In the case of refined 0.45% carbon steel

Abstract

Using a two disc machine, conditions to give rise to scuffing or to prevent scuffing were investigated with 0.45% carbon steel annealed which has much ability to be work-hardened. Following three factors were considered to be most important associated with the occurrence of scuffing, that is, bulk surface temperature, severity of contact, and surface resistance to scuffing. Three different critical conditions of surface temperature related to scuffing should be taken account of. The first one is the transition temperature, the second one is about 180°C at which the composition of oxide films formed on the disc surfaces seems to be changed, and the third one is about 240°C at which black surface films begin to be formed. The severity of contact could be represented by dimensionless film thickness. The surface strength could be expressed by the surface hardness taking account of work-hardening during testing, which is always accompanied by the formation of oxide film. The existence of critical surface strength according to operating conditions, above which there is little chance of scuffing, is confirmed.