One of the most promising method of obtaining wear, erosive and corrosive resistant coatings is the gas-dethonation method. The coatings produced by this method permit widening the application range due to increasing of useful properties of low alloy steels. The paper deals with the influence of technological parameters on the properties of coatings produced from tungsten carbide powder on 1045 steel. The role of modifying the substrate surface before process is discussed. The three method of changing the surface are presented: grinding, sand-blast cleaning and sanding by gas-detonation method. The microstructure of the WC coatings are described by metallographical and scaning electron microscopy (EDS method) investigations. The preparation of the substrate surface using a sand paper, compressed air sand blasting or detonation sand blasting, aimed at making this surface more developed, worsened the adhesion of the coating to the substrate, since the substrate-coating interface zone was then more porous with respect to that observed when the coating was deposited on a ground substrate.