Prediction of the high temperature crack propagation in the AISI 304L steel using the cohesive approach

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angličtina

As a result of operational stress, metal materials degrade. At elevated and high temperatures, which are the operating conditions of a number of power plants, a significant process under static stress conditions is slow time-dependent plastic deformation – creep, often associated with intergranular breakage. These processes lead to a limitstate determining the creep life of the component and eventually to intergranular creep fracture, usually associated with very low creep strain values. Due to these very low values of strain to fracture, the process of creep deformation is very dangerous. Problem turns both to knowledge of the microscopic processes in front of the crack front and in the whole body, since these failure processes can be governed by different laws than the failure processes at large distances from the crack front. The behaviour of a dimensional crack during creep is the subject not only of experimental observation, but also of crack propagation modelling using the cohesive approach implemented in the finite element method (FEM). From experimental observations follows that macroscopic crack propagation is critically dependent on two competing processes: a) relaxation of the stress concentration at the crack front by creep deformation, leading to crack blunting, b) acceleration of the cavitation process (creep intergranular failure) in front of the crack front. In the presented article, both experimental and numerical procedures are used to estimate the behaviour of these bodies with a priori crack of this austenitic steel, whose designation according Czech standard is also 18CrNi.

high temperature crack propagation; AISI 304L steel; cohesive approach

KOZÁK, V.; VALA, J.

28. 2. 2024

American Institute of Physics 978-0-7354-4873-5

Melville (USA)

978-0-7354-4873-5

Thermophysics

1

1551-7616

AIP Conference Proceedings

3126

1

Spojené státy americké

020011-1

020011-6

6

https://pubs.aip.org/aip/acp/issue/3126/1