The present work shows the behaviour of low carbon alloyed steels as AISI-SAE 8615, after a ferritic nitrocarburizing process. Nitrocarburizing takes place at 570oC for 3 h in an atmosphere by combustion of methanol and urea under different flow rates. Metallographic studies were performed by optical microscopy. Hardness profiles were measured and carbon percentages were also analized by emission spectrometry in order to determine the extension of the nitrocarburizing process. Optimal flow conditions have been found. The influence of the flow rate on the nitrocarburizing layer thickness has been also studied.