The effect of the surface quality of the material on the operational properties of the heating elements

Purpose. To improve durability and trouble-free operation of electric furnaces it is required to ensure reliable operation of their most important element - heater. As a material for heating elements heat-resistant steels and alloys shall be used. Extensive application among them find Fe-Cr-Al alloys. To increase durability of the heaters it is required to improve surface quality of the heaters and, consequently, technological and service properties. Methodology. The article describes the main factors which affect the process of formation of dense oxide films, analyzed defects that are observed on the surface of the wire, used for manufacture of heating elements of electric resistance furnaces. It shows that ensuring formation of dense and adherent scale of protective oxide films such as spinels FeO-(AhO3, &2O3) on metal surface, plays an important role in improvement of corrosion resistance. Findings. During the study of the surface layer of wires Х15Ю5, Х20Н80 it was found that on the surface of the metal there were defects formed during the factory production of the wires. The article presents a comparative analysis of the surface of steel wire 03Х23Ю5Т before vapor-plasma discharge treatment and after the treatment which lasted for 30 seconds and 6 minutes. Originality. Researchers have extensively studied the effect of reactive alloying elements Ca, Ce, La, Y, on the properties of protective oxide films: adhesive capasity of the oxide layer, its plasticity and growth rate. However, the relation between quality of the surface of the wire for the heaters and technological, operational properties has not been established. Practical significance. Service life of a furnace before the overhaul is directly connected with the service life of heating elements. Consequently, increasing the service life of the heater is an important issue, both from technical and economical points of view. Necessity for use of joint integrated modification with additional vapor-plasma discharge treatment for improvement of technological and operational properties of Fe-Cr-Al alloys is identified and justified.