Effect of austempering treatment on lubricated sliding contact of compacted graphite iron
2020 (English)In: SN Applied Sciences, ISSN 2523-3963, E-ISSN 2523-3971, Vol. 2, no 12, article id 1947Article in journal (Refereed) Published
Abstract [en]
Significant research has been done to improve the wear properties of the components used in internal combustion engines. Excessive wear is observed in components such as cylinder liners and rings, which can lead to lower volumetric efficiency of the engine, increase oil consumption, polluting emissions, and scuffing related issues. Since tribological systems in internal combustion engines are complex, the different wear mechanisms involved need to be investigated to improve the life of components. Cast irons are commonly used for engine components, especially compacted graphite irons (CGI) for piston rings and gray cast irons (GCI) for cylinder liners. This work aims to evaluate the tribological behavior of two different microstructures of CGI (pearlitic and ausferritic), sliding on pearlitic GCI. The samples of CGI with different microstructures and hardness were evaluated in a short-stroke reciprocating sliding tester, using Petronas Urania SAE 30 API CF lubricant oil at 100 degrees C for four hours. The characterization of worn surfaces was made using a scanning electron microscope (SEM) and 3D roughness measurements. The coefficient of friction (COF) comparison between the two CGI microstructures showed very similar results with COF =0.11. The pearlitic CGI showed more severe wear than the austempered one, confirmed by SEM images and the difference in topography parameters before and after the tests. Phosphorus, sulfur, and zinc were detected by EDS analyses in the samples' worn-out regions, indicating the formation of tribo-films, which was further confirmed by the friction tests.
Place, publisher, year, edition, pages
Springer Nature Switzerland AG , 2020. Vol. 2, no 12, article id 1947
Keywords [en]
Compacted graphite iron, Austempering, Piston rings, Cylinder liners
National Category
Materials Engineering Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:his:diva-21991DOI: 10.1007/s42452-020-03772-1ISI: 000587307600004Scopus ID: 2-s2.0-85100815400OAI: oai:DiVA.org:his-21991DiVA, id: diva2:1707872
Funder
Knowledge Foundation, 20170021
Note
© 2022 Springer Nature Switzerland AG. Part of Springer Nature.
The material provided in this collaborative work was partly supported by the AusCGI project [funded by Stiftelsen för kunskaps- och kompetensutveckling (KK-Foundation)], Sweden, under the Prospekt scheme [GNR. 20170021]. Federal-Mogul AB and Bodycote are greatly acknowledged for their materials and helping with the heat treatments, respectively. G. Pintaude thanks CNPq for a scholarship through Process 308416/2017-1. The authors also thank the Multi-User Center for Materials Characterization (CMCM) of the UTFPR SEM-EDS analysis and MAHLE METAL LEVE for supplying samples.
2020-11-302022-11-012023-03-28Bibliographically approved