This chapter presents three articles with results, about our research, relationships with the behavior corrosion resistant in different materials of engineer. The first research is about TiC monolayers and Ti/TiN/TiC/TiCN multilayers were deposited onto AISI 4340 steel substrates at 300o C and 4.0x10-2 mbar nitrogen/methane pressures by using a Pulsed-Laser Deposition technique. A Nd: YAG laser (1064 nm, 500 mJ and 7 ns), with a repetition rate of 10 Hz was used. Here we analyzed the difference in structure and mor‐ phology for single layers and multilayers structures deposited on stainless steel sub‐ strates. AFM analysis presented different morphologies; showing, that the single layer had an average grain size of 0.087 μm; while the multilayers exhibited grain sizes of 0.045 μm. Coating thicknesses were 1 μm, approximately, and monolayer average rough‐ ness was 0.21 μm; while a value of 0.15 μm was measured for multilayers. Under a 60 Kg maximum load applied in tension to evaluate the adhesion to the substrate, no de‐ tachment of the films was presented. Multilayers evidenced better impact resistance as compared with TiC single layer; this result is considered, bearing in mind that in multi‐ layers propagation of fissures is slower, because the presence of layer inter-phases, lead to fissures strays in other directions. Slight corrosion specks are present; but mass loss was around 16 mg. in multilayers a value was lower than for the TiC single layer that was near 43 mg. Homogeneity, grain size, fracture resistance, corrosion resistance, and adhesion of the multilayers are suitable for mechanical applications of these types of coatings as shown in mechanical measurements. These results indicate that for engineer‐ ing applications under corrosive environments, the use of this type of multilayers coat‐ ings on AISI 4340 steel, are highly recommended.