IRSN, Institut de radioprotection et de sûreté nucléaire

Search our site :


Contact us :

En Fr

Enhancing Nuclear Safety



Tests and numerical analysis of cracked rings under thermal shock in the brittle/ductile transition of a pressure vessel steel

M. Reytier, S. Chapuliot, L. Ferry*, M. Nédélec**,

ASME Pressure Vessels and Piping Division Conference, Denver, Colorado-USA, July17-21, 2005,
Rapport DSR 113

Document type > *Report/contribution to WG (paper or CD-Rom), *Congrès/colloque

Keywords > reactor vessel, thermal shock

Research Unit > IRSN/DSR/SAMS

Authors > NEDELEC Michel

Publication Date > 30/03/2006


Thermal shocks and temperature gradients associated with large thickness constitute difficult loadings for structures integrity analysis. Moreover, at low temperature or because of irradiation effects, the pressure vessel steel 16MND5 undergoes a transition in fracture mode which may lead to cleavage initiation. The prevention of this fracture mode is generally ensured by first staying outside the brittle domain and secondly, by imposing a stress intensity factor below the fracture toughness which is determined from monotonic and isotherm standard tests. But, with various temperature - loading histories, this criterion is not faultless. Therefore, in order to study in detail rupture under thermal shocks, with several loading types (mechanical and/or thermal laodings), a specific-adapted cracked ring has been developed. It consists of a 50mm thick ring which has a crack on the external diameter and several holes through the specimen to locally heat the ring by injecting hot water which can lead to crack initiation. This particular test allows the study of crack initiation with only thermal loading or both thermal loading and external mechanical loading. This article describes in details several tests including one with cleavage rupture. Moreover, numerical calculations are presented to estimate the mechanical fields at the crack tip and the global fracture mechanism parameters as a function of the temperature. Several rupture criteria are then applied to predict the initiation.

* CEA Saclay, ** IRSN Fontenay-aux-Roses,

Send Print

More information


Send to a friend

The information you provide in this page are single use only and will not be saved.
* Required fields

Recipient's email:*  

Sign with your name:* 

Type your email address:*   

Add a message :

Do you want to receive a copy of this email?