Resumo

MIRANDA, J. C.; RAMALHO, A.  e  CAVADAS, Sérgio. Efeito da temperatura de revenido no comportamento tribológico do aço din 100Cr6. C.Tecn. Mat. [online]. 2006, vol.18, n.1-2, pp.35-42. ISSN 0870-8312.

The steel DIN 100Cr6 is often used in highly stressed mechanical components. It is mostly used on rolling bodies and bearings rings. This steel is usually used in tempered state and it is tempered to the maximum hardness. With low temperatures of tempering we can obtain a hardness higher than 7,5GPa. However, in some utilisations of this steel, the temperature can already be significant, without being yet necessary to use special steels for high temperatures. In these cases, the heat treatment has to be readjusted, in particular the tempering temperature. As the tempering temperature produces a significant variation of the hardness and tenacity, the wear resistance will certainly be affected. The main purpose of this work is to study the influence of the microstructure variation on the friction and wear of the steel DIN 100Cr6. The microstructure variation was produced by variation of the heat treatment, more specifically of the tempering temperature. To obtain this, the rotative specimens were treated using different tempering temperatures between 200ºC and 500ºC. To evaluate de variation produced on the wear resistance, we have used two techniques: friction and wear tests with crossed cylinder contact in unidirectional sliding and tests of micro-abrasion by sphere. The results obtained are widely discussed, having into account the wear mechanisms observed and the hardness and microstructure variations resultant from the heat treatments. One other aim of the present study was to verify the new energetic parameters aptitude to quantify the wear resistance. The results of this study are perfect to the concretisation of this aim, because, using the same chemical composition and with successive variations of the microstructure, it is possible to change significantly the tribological behaviour. The results of the tests of sliding are compared considering both the classical Archard approach, and the use of new parameters based on the relation between the dissipated energy by friction and the wear volume.

Palavras-chave : Wear; Friction; Heat Treatment; Dissipated Energy.

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