Forgeabilité des aciers inoxydables austéno-ferritiques

tel-00672279, version 1 - 21 Feb 2012
150 Chapter IV. STRAIN PARTITIONING
IV.7.4 Limitations due to experimental conditions
The temperature range of the industrial hot rolling process is between 1000 and 1280°C and the strain
rate range is between 1-100s -1 . That is why a few microgrid experiments have been performed at a
temperature of 1050°C and a strain rate of 10s -1 . These experimental conditions turned out to be so
constraining that no satisfying results could be obtained. It was extremely difficult or impossible to
extract the deformed microgrids from the plane strain compression specimen. Indeed, the two inserts
were welded together by diffusion. Even when it was possible to separate the two inserts, the de-
formed microgrids were strongly damaged or not clearly visible as shown in Figure IV.45. It means that
using the microgrids technique above 1000°C requires additional experimental developments.
20 μm
Figure IV.45. SEM micrograph showing the deformed microgrids after plane strain compression at
1050°C and 10s -1 .