National Repository of Grey Literature 2 records found  Search took 0.01 seconds. 
Vliv zatěžovací historie na creep 9% chromové oceli
Kloc, Luboš ; Sklenička, Václav
The creep life assessment is currently based on the phenomenological models mostly derived from the constant stress or constant load creep experiments. Since the loading history of the parts in industry used to be complicated and frequently unknown, the model data can be invalid. Stress change creep experiments were done on the P-91 type creep resistant steel at loading conditions corresponding to the low stress creep regime. The experiment was interrupted, that is cooled down and heated up again several times. The interrupts were done during the ``quasi-steady state'' when the creep rate is stabilized. The effect of both stress changes and temperature cycles on creep properties was analyzed. While the temperature cycle introduce some additional creep strain, the stress changes reduce the creep rate considerably. Taking into account the proportionality between the creep strain and creep damage nucleation, it is possible to conclude that small stress changes during primary stage can improve the creep strength of the steel, while the temperature changes have opposite effect.
Creepové chování modifikované 9 Cr martenzitické oceli po dlouhodobém žíhání
Sklenička, Václav ; Kudrman, J. ; Kuchařová, Květa ; Míková, R. ; Kloc, Luboš ; Svoboda, Milan
The results show that the creep resistance of the aged steels is considerably deteriorated by comparison with steels in the as-received state in the dislocation creep regime.By contrast, no significant effect of microstructural stability on creep behaviour was found in a regime of viscous creep.

Interested in being notified about new results for this query?
Subscribe to the RSS feed.