Intergranular damage in AISI 316L(N) austenitic stainless steel at 600°C : pre-strain and multiaxial effects

Quentin Auzoux (1) , Lucien Allais (1) , Christel Caës (1) , B. Girard (1) , I. Tournié (1) , Anne-Françoise Gourgues (2) , André Pineau (2)

1 SRMA - Service des Recherches Métallurgiques Appliquées
2 CDM - Centre des Matériaux

This study is devoted to the effect of a multiaxial stress state and of pre-straining on the creep properties of an austenitic stainless steel. Creep tests on both smooth and notched specimens have been carried out on type 316L(N) steel at 600 °C. In comparison to the annealed state, pre-straining caused a substantial increase in creep lifetime but also a dramatic drop in intergranular damage resistance. The effect of a pre-strain on creep ductility was so strong that compact tension specimens in pre-strained state tested under relaxation conditions cracked, whereas specimens in annealed state were not prone to cracking. A model taking into account both pre-strain and multiaxial effects was developed and identified on the basis of local intergranular micro-cracks measurements on notched specimens. It satisfactorily predicts the results of relaxation crack propagation tests. This model may also provide a useful estimation of the relaxation cracking risk of 316L(N) as a function of pre-strain level and stress triaxiality ratio.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Quentin Auzoux, Lucien Allais, Christel Caës, B. Girard, I. Tournié, et al.. Intergranular damage in AISI 316L(N) austenitic stainless steel at 600°C : pre-strain and multiaxial effects. Nuclear Engineering and Design, 2005, 235, pp.2227-2245. ⟨10.1016/j.nucengdes.2005.05.002⟩. ⟨hal-00153284⟩