Damage phenomena in lubricated rolling-sliding wear of a gas carburised 0.85%Mo low-alloyed sintered steel: theoretical analysis and experimental verification

ABSTRACT

The resistance to surface and subsurface damage during lubricated rolling-sliding wear of a carburised low-alloy sintered steel and the effect of shot peening were investigated. The formation of both contact fatigue cracks and of brittle tensile cracks may be predicted by a theoretical model that was experimentally validated. Carburising is effective in increasing the resistance to contact fatigue, but pores in a hard and brittle matrix may act as pre-existing cracks. Shot peening increases the contact fatigue resistance since compressive residual stresses oppose the nucleation of surface cracks.

KEYWORDS:

• Contact fatigue
• surface tensile cracks
• carburising
• shot peening

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Samuel Tesfaye, MSc in Materials Engineering, PhD student at Department of Industrial Engineering, University of Trento.

Alberto Molinari, PhD in Metallurgical Engineering, full professor of Metallurgy at Department of Industrial Engineering, University of Trento.

Wolfgang Pahl, PhD in Physics, R&D Manager at GKN SinterMetals in Bruneck.