Evolution of fretting wear with the number of cycles on Inconel 690 steam generator tubes against AISI 420 steel under gross slip conditions

The evolution of fretting wear with the number of cycles for Inconel 690 steam generator tubes against AISI 420 pads in air at room temperature was studied in a 90° cross-cylinder configuration. Tests were performed under a contact load of 10 N and a displacement amplitude of 50 μm to a total number of cycles between 102 and 106. Fretting wear associated with gross slip was identified as the main damage mechanism. The maximum wear depth was a better descriptor of wear evolution than the Archard defined wear coefficients due to the lack of linearity between wear volume and number of cycles. Debris detached at 106 cycles consist of agglomerates of 5–20 nm sized nanoparticles with chemical composition (Ni, Fe) (Fe, Cr)2O4. •Archard coefficients are not adequate to predict evolution of wear with cycles.•Fretting process reaches a stationary state above 105 cycles in gross slip regime.•Average value of friction coefficient in the steady regimen was 1.3 ± 0.15.•At 106 cycles, debris sized 5–20 nm with composition (Ni,Fe) (Fe,Cr)2O4 were found.•Testing under ASTM G204 results in a wear coefficient of 22 × 10−15 Pa−1.