Several aspects of the temperature history in relation to the cyclic behaviour of an austenitic stainless steel

A consistent mechanical and transmission electron microscopy (TEM) database is proposed to discuss the consequences of dynamic strain ageing (DSA) on the temperature history memory effect observed under the cyclic loading of a 316LN austenitic stainless steel. Two DSA mechanisms have been identified in relation with two temperature regimes: the first of which may be related to the Suzuki effect (in the low temperature regime) and the second is linked to solute segregation at dislocation node (in the high temperature regime). The temperature history memory effect is a function of the temperature range and can be explained in terms of chromium segregation and the potentiality to obtain 'stability' in dipolar dislocation structures. Both aspects are discussed based on the measurement of internal stress changes. (authors)