ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Surface and depth morphology evodslutions of short crack propagation of 1Cr18Ni9Tiweld metal are investigated. In accordance with the previous effective short fatigue crack (ESFC)criterion, attention is paid on the formation zone of the dominant ESFC (DESFC), which resultedfinally in the specimen failure, in micro-structural short crack (MSC) regime and then, the tip zone(s)ahead of the DESFC in physical short crack (PSC) regime. Results show that in MSC regime thesurface ESFCs were imitated from the distributed randomly delta ferrite bounds separated fromaustenite matrix. The initiated ESFCs on surface propagated perpendicularly to loading axle. But indepth direction, the initiated ESFCs grew first similarly to the surface behaviour but lately, tended tobe perpendicularly to the formation direction of the material columnar grain structure. When sizes ofsome longer ESFCs reached around the material maximum barrier size, coalescence occurred to forma true DESFC. In PSC regime the surface DESFC grew almost perpendicularly to loading axle. But indepth direction, it grew first perpendicularly to the formation direction of the columnar grain structureand then, tended to having 45 degree angle to the loading axle. Obviously, the evolutions werestrongly affected by interactions between the load and the microstructures, especially, the columnargrain structure
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/55/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.353-358.46.pdf
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