This paper studies the formation of boride layers on substrate injector combustion AISI 304 per nozzle surface treatment in addition the formation of hard layers and FeB type Fe2B were obtained in a temperature range of 1223 and 1273 K with exposure times of 1/2, 1, 3 and 5 h. The study consisted boride type layer formed on the surface and the characterization of the boride layer were evaluated by the method by analysis of X-ray diffraction (XRD), the distribution of the alloying elements were detected by spectrometry energy Dispersive (EDS) inside the surface, the evaluation of adhesion of the layers was determined by the technique Rockwell-C hardness was also evaluated and the Young's modulus of the layer by the nanoindentation technique with the load of 200 mN. Finally this study hardening fuel injector; is desired increase its useful life.