Creep of the austenitic steel AISI 316 L(N). Experiments and models

This report provides a general review on deformation mechanisms relevant for metallic materials. Different mechanisms are described by rate equations which are derived and discussed in detail. For the example of an austenitic 17Cr12Ni2Mo steel (AISI 316 L(N) or DIN 1.4909) these equations are applied to experimental creep data from own investigations at IMF-I (especially long-term creep tests with creep times of up to 10 years) and from NRIM, Japan. Step-by-step a steady-state creep model is set up that is able to predict creep behaviour in a wide temperature and stress range. Due to the small number of adjustable parameters it may also be easily adapted to other materials. Since austenitic stainless steels are well known for their problematic aging behaviour at elevated temperatures, microstructure and precipitation formation as well as their impact on creep are outlined above all.