Combination of mechanical and chemical pre-treatments to improve nitriding efficiency on pure iron

In this paper, the efficiency of gas nitriding on pure iron is observed regarding two types of pre-treatments prior to nitriding: chemical reduction by H2 and nanocrystallization by NanoPeening®. Thermogravimetric analysis reveals that both pre-treatments result in an increase in the transformation rate of nitrogen during the first 200 min of nitriding. Moreover, glow discharge optical spectrometry reveals that nanocrystallization by NanoPeening® leads to a deeper penetration of nitrogen in the material.