The formation of functional powder covering on steels and alloys under the extreme heat exposure

Abstract

Abstract The research shows the results of experiments on structure and characteristics of different chemical powder coverings laser processed on steels and alloys. It is proved that laser irradiation of the surface of the materials with slip coverings is an effective means of improving the basic performance properties of hardened products, especially when using coverings containing hard refractory carbides, nitrides, oxides of alloying elements. The contents of coverings must be found in accordance with the required functional properties of the hardened products in different performances. Laser alloying should be carried out with a radiation power density in the range of 100–200 MW/m2, the lowest limit is applied for irradiation with pulses of 1–3 ms, the highest limit is at 4–10 ms. Rational choice of laser operation modes and powder covering content on the working surfaces of irradiated products increases hardness by 30–50%, heat resistance by 50–70 °C, wear resistance by 2–3 times in comparison with the original steels after standard volumetric heat treatment.