The effect of manufacturing method and running-in load on the surface integrity of efficiency tested ground, honed and superfinished gears. (March 2019)

• Record Type: Journal Article
• Authors: Mallipeddi, D.; Norell, M.; Sosa, M.; Nyborg, L.
• Is Part Of: Tribology international. Volume 131(2019)
• Page Start: 277
• Page End: 287
• Publication Date: 2019-03
• Subjects: Gears -- Finishing processes -- Surface integrity -- Efficiency testing; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2018.10.051
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: This study compares gear surface characteristics generated by grinding, honing and superfinishing of case-hardened steel, including the evolution during efficiency testing with two different prior running-in loads (0.9 GPa and 1.7 GPa). The most influential factor was surface roughness. Micro-pitting was associated with surface asperities and hence only seen in ground and honed gears, while being absent for super-finished gears. The micro-pitting was enhanced by running-in load, but only for rough surfaces. Deformation-induced localized microstructure impact was associated with cracks. Residual stresses reached similar levels after efficiency testing. Phosphorous content in the gear surface was connected to surface roughness and running-in load. Highlights: The most influential surface characteristic was roughness. Running-in load influenced the evolution of surface characteristics and micropitting, but only for rough surface. Deformation induced localized bands confined to < 7µm were found to be in connection with the cracks. The variation in residual stresses between as-manufactured conditions is associated with retained austenite content. The phosphorous content in the gear surface was enhanced by the roughness and running-in load.