The influence of jet gas temperature on the characteristics of steel coating obtained by wire arc spraying

In the arc spraying processes, velocity and temperature of the sprayed particles, which are in a close relationship with the drive jet velocity and temperature, influence the physical and mechanical properties of the coatings. This paper presents a comparative research of 30 T steel deposits, carried out by two spraying procedures: the classic wire arc spraying procedure plus a new one, which represents a combination between the classic wire arc spraying and the flame spraying procedure. The use of a new procedure allowed the increase of the drive jet temperature and the study of its effect created on 30 T deposits properties. The modelling of the arc spraying and the analysis with finite elements in a coupled field allowed the determination of the drive jet temperature variation and the fuel flow, necessary for the temperature to be maintained over 1000 K at spraying distance of 150 mm. The investigations carried out on 30 T steel coatings, obtained by this procedure, demonstrate that the spraying jet temperature increase determines the average growth of the coatings adherence over 18% for cylindrical surface and over 5% for flat surface. Also, these investigations demonstrate the decrease of the average porosity by over 22% for cylindrical surface and by over 17% for flat surface.