Étude par diffraction des rayons X de la nitruration plasma d'un acier 304L – Influence sur l'oxydation à 1000 ○C

This work presents the influence of various nitridation parameters on the 304L steel oxidation at 1000 C, in air under atmospheric pressure. Nitridation temperatures were ranging between 300 C and 430 C with exposure times lasting from 2 to 8 hours. At 300 and 430 C, the nitridation treatment leads to the solid solution surface formation -N without any nitride formation. After oxidation at 1000 C of blank specimens, X ray diffraction reveals the FeCr 2 O 4 spinel formation. This oxide does not act as a good diffusion barrier. With nitrogen treated specimens, the higher the nitridation temperature is and the longer the exposure time is, better is the oxidation behaviour at 1000 C. We then observe that the Cr 1,3 Fe 0,7 O 3 oxide is more present in the oxide sale from the very beginning of the oxidation test which is correlated to a final lower mass gain.