Filtern
Dokumenttyp
- Zeitschriftenartikel (17)
- Beitrag zu einem Sammelband (17)
- Beitrag zu einem Tagungsband (15)
- Vortrag (8)
Sprache
- Deutsch (28)
- Englisch (28)
- Mehrsprachig (1)
Schlagworte
- Cryotechnology (3)
- Friction (3)
- Stainless steel (3)
- Transfer film (3)
- Gleitlacke (2)
- Hydrogen (2)
- Kryotechnik (2)
- Phase transformation (2)
- Reibungszahlen (2)
- Stacking fault energy (2)
Eingeladener Vortrag
- nein (8)
Investigations have been carried out on an erosion-corrosion apparatus to investigate the behaviour of corrosion-resistant highalloy iron-base materials containing hard phases. These materials had been optimized for increased wear resistance under complex stress conditions. As expected, in dry erosion tests, very low mass losses were established; there was little difference between the materials. Also, in corrosive environments (NaCl, H2SO4), the materials showed good stability; however, the duplex structures were superior to the martensitic ones. The combination of erosion and corrosion produced large differences and, in some cases, markedly reduced resistance to damage. These results confirmed observations that it is impossible to deduce the environmentally influenced mechanical behaviour of an alloy from its behaviour in separate corrosion and erosion experiments. The basic mechanisms underlying these processes have been investigated only tentatively.
Phase transformations in austenitic stainless steels during low temperature tribological stressing
(2001)
The tribological behaviour at low temperatures is unknown for many materials even for those widely used in cryogenic engineering. Because of the extension of applications of low temperature technologies there is a need for investigations in this field. It is the aim to study the stability of the austenitic structure of FeCrNi alloys under these harsh conditions. This paper deals with tribological experiments with alloys of different stability of the austenitic structure in the temperature range between room and liquid helium temperature. It was found that alloys stable at room temperature show martensitic transformation under tribological stressing and decreased service temperature. The obtained transformation behaviour does not exhibit a linear tendency down to liquid helium temperature. A maximum could be stated.
This paper presents investigations on the tribological behaviour of PTFE composites against steel at cryogenic temperatures. The results showed that the friction coefficient decreases with temperature down to 77 K, but did not follow a linear evolution further down to extreme low temperatures. It can be stated that the cryogenic environment has a significant influence on the tribological performance of the polymer composites. The effect of low temperatures was more clearly detected at low sliding speed, where friction heat is reduced. A change in wear mechanism from adhesive to abrasive was observed in this case. SEM and AFM analyses showed that the PTFE matrix composites investigated under these experimental conditions have transferred material onto the disc down to very low temperatures. Chemical analyses indicate the presence of iron fluorides.