Creep Failure Behaviour of a 9CrMoNbV Weld Metal with Anisotropy Under a Biaxial Loading State

Abstract

The ‘bulk’ material creep failure behaviour of an anisotropic 9CrMoNbV weld metal, under biaxial loading conditions, was investigated, using creep damage analyses with a ‘unit cell’ model. The model consists of a columnar region and a weaker ‘equiaxed’ (fine-grained and coarse-grained) region. Creep damage analyses were conducted using a single-variable Kachanov-type damage law, for which the material constants were obtained from experimental data. The bulk material creep rupture lives, under a range of biaxial load ratios, were determined, including the effects of a triaxial stress state parameter for the material. The typical failure modes are described and isochronous creep rupture curves and master load loci are presented.

Keywords

creep damage failure life anisotropy 9CrMoNbV weld metal biaxial loading

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