Variable pressure scuffing of a flake graphite cast iron diesel cylinder liner

A novel scuffing methodology was developed utilising variable specimen geometry to replicate numerically modelled top compression ring contact pressures (4–62 MPa) from a 12.8-litre heavy duty diesel engine as function of stroke position. Scuffing grade 250 cast iron induced by reciprocating sliding (TE77) against drip lubricated (PAO4) 52100 rectangular operating at 15 Hz and 311 N normal load incrementing the temperature 4°C per minute until sharp rise in friction coefficient observed. initiation insensitive dynamic pressure. Formation an oxide ‘glaze’ layer resulted coefficients low 0.03 prior severe scuffing.