Rolling contact fatigue and wear properties of 0.1C–3Cr–2W–V nitrided steel

• The nitrided layer of about 220–230 μm was obtained on 0.1C–3Cr–2W–V steel surface.
• Wear behaviour, RCF properties and failure mechanism of the layer were evaluated.
• Friction coefficients of nitrided steel are decreased from 6% to 29% at various loads.
• Maximum RCF life of nitrided steel prolongs by 4.5 times compared with untreated one.
• Spalling and delamination within layer are main failure modes of the nitrided layer.

Rolling contact fatigue (RCF) characteristics of 0.1C–3Cr–2W–V nitrided and untreated steel have been investigated at ambient temperature. The results indicate that the friction coefficients of the nitrided specimens decreased from 6% to 29%, and the RCF life of the nitrided specimens have been significantly prolonged. The failure modes of the nitrided surface could be classified as spalling and delamination within the layer, and the inner defects generated by the plasma nitriding play an important role in the surface and subsurface initiated RCF. Meanwhile, decreased surface roughness and better wear-resistance are demonstrated to be useful to improving the RCF performance.