Effect of contact pressure on fretting fatigue behaviour of AISI 304 stainless steel

Fretting fatigue behaviour of AISI 304 austenitic stainless steel was studied at three different contact pressures (50, 100 and 150 MPa). Friction force and surface roughness of fretting scar in tested specimens increased with increase in contact pressure. The fretting fatigue life decreased monotonously with increase in contact pressure due to higher stress concentration and increased surface damage. Multiple crack initiation was observed in specimens tested at higher contact pressures. Though the samples tested at a contact pressure of 150 MPa exhibited the lowest fatigue lives, more martensite formed in the fretting region compared with that in specimens tested at lower contact pressures of 100 and 50 MPa.