Creep and creep crack growth studies on Alloy 800H
When designing a high temperature plant, reliable experimental data, obtained under testing conditions which accurately represent the actual service conditions, are most desirable. This paper outlines work performed to characterise the creep and creep crack growth behaviour of the austenitic steel Alloy 800H under potential service conditions. To ensure adequate simulation, a tube was chosen as the test piece, a form in which the material is most frequently encountered in high temperature service. The tubes were subjected to multiaxial loading from uniaxial tension and/or internal pressure. During creep crack growth studies, both the geometries and orientations of the initial spark eroded defects were similar to flaws encountered in a plant. Analysis of the results obtained from multiaxial creep testing allows the elucidation of the operative multiaxial stress criterion for both deformation and rupture, based on a comparison of the multiaxial data with the conventional uniaxial data, metallographic investigations and material deformation behaviour modelling. Similarly, limit load solutions are shown to describe the creep rupture behaviour of notched tubes, while the C(*) integral relates the creep crack growth data derived from measurements on notched tubes with conventional data obtained from compact tension tests on the same material.
Bibliographic Reference: Paper presented: 6th International Conference on Mechanical Behaviour of Materials, Kyoto (JP), July 29 - Aug. 2, 1991
Availability: Available from (1) as Paper EN 36054 ORA
Record Number: 199110696 / Last updated on: 1994-12-02
Original language: en
Available languages: en