MECHANICAL PROPERTIES OF HEAT-STRENGTHENED STEEL 65G SURFACE-REINFORCED WITH HARD-ALLOY SURFACING

Increasing the service life of soil-cultivating equipment parts by the use of surfacing reinforcement of working surfaces has found a fairly wide application. However, the studies carried out on this problem were focused on parts, the metal of which had not been subjected to preliminary heat hardening. Meanwhile, in recent years, the components of the working tools of agricultural implements are almost completely hardened by heat treatment. This is especially true for imported products. Information on the reinforcement of parts that have undergone this kind of processing is extremely scarce, and sometimes contradictory. Therefore, the research task was to study the properties of heat-strengthened steel 65G after its surface reinforcement. During the experiments, as the base metal, use was made of spring sheets made of 65G steel with a hardness of about 45 HRC. T-590 electrodes were used as the surfacing material, intended for surfacing of parts operated in an abrasive environment. The reliability of the results obtained was guaranteed by a large number of measurements. Mechanical properties were evaluated by HRC hardness. As a result of experiments, it was found that the hardness value of 44…47 HRC for leaf springs taken out of service makes them suitable for use as repair materials. When surfacing one roller, the initial hardness of the base metal remains at the same level; surfacing two rollers leads to a decrease in HRC by 9 units. Three zones are distinguished in the area between the rollers. The use of reinforcing rollers on the surface of heat-treated steel 65G increases its service properties due to their high hardness, a decreased contact path of the abrasive particle with the working surface and forms a “fl uidized” layer of a moving abrasive medium between the rollers.

Determining Impact Forces on a Ferromagnetic Particle in the Process of Magnetothermal Surface Reinforcement of Products from Thermoplastic Polymers

The author considers the forces acting on a ferromagnetic particle from the side of the magnetic and thermal fields, as well as the forces opposing its penetration from the side of the surface layer of the polymer. The calculation of the forces acting on a ferromagnetic particle in the process of its introduction into the surface layer of the polymer is carried out using the example of nickel and polypropylene. The balance of forces required for the introduction of a ferromagnetic particle into the molten surface of a thermoplastic polymer and stable fixation in it is calculated. The universality of the approach used is shown for calculating the parameters of surface modification of thermoplastic products with different properties by ferromagnetic particles of different dispersion and characteristics.