A numerical and experimental assessment of the small

Research output: Contribution to journalArticlepeer-review

Authors

  • EC - JRC - European Commission - Joint Research Centre
  • EC - European Commission
  • EC - JRC - European Commission - Joint Research Centre

Documents & links

DOI

Abstract

This paper presents a finite element analysis of the small punch creep test for 316L(N), which is compared with experimental data for 650 and 700 C. Special emphasis is placed on (i) assessing the influence of friction and (ii) comparing two different creep models: the simple Norton creep and the more general creep model. The computed normalized deflection rate versus time is almost identical for all cases, which allows for scaling of the results. The computed time to rupture increases linearly with the friction coefficient due to a reduction in the mean stress. There is a good overall agreement between the experimental values and the computed deflection rate for a friction coefficient of around 0.3. It is shown that the initial reduction in deflection rate is due to stress relaxation and homogenization, and is only marginally affected by primary creep hardening. The computed results are compared with the equivalent stress and strain rates in the recently published small punch standard (EN 10371). The computed von Mises stresses at minimum deflection decrease linearly with the friction coefficient but are consistently slightly higher than the equivalent stress in
the standard. For the strain rates, the computed values are significantly higher than the equivalent values in the standard. The presented simulations give a deeper insight of the small punch creep and impact of key parameters such the friction coefficient and in general as a guidance to refinement and
improvement of the empirically based formulae in the standard.

Details

Original languageEnglish
Article number11101609
Pages (from-to)1-21
Number of pages21
JournalMetals
Volume11
DOIs
Publication statusPublished - 11 Oct 2021

Keywords

  • Small punch test, 316l(N), Creep, Creep rupture, Time to creep rupture, Friction, Finite element, Stress relaxation, Austenitic steel

ID: 7483351