The influence of contact loads on the properties of the working plated layer grain grinders

Abstract

The influence of contact loads on the change of structure and properties of working welded layer of knives of grain grinders is considered in the work.

Factors such as: hammer material; the load and rotation speed of the grain crusher drum affect the durability of the coatings. Strengthening the micro-volume of the metal in the process of phase transformations promotes its hardness and wear resistance of the weld metal. Under the influence of contact loads, plastic deformation of the surface layers occurs as a result of slander and additionally due to deformation transformation. Investigation of the microstructure of the weld metal by optical microscopy revealed the formation of a multiphase structure. With rapid cooling, the welding process fixes the structure that was under heating, as polymorphic transformations do not have time to go through, and excess phases are released. The resulting structure allows the deposited layers to be subjected to cold plastic deformation, in the process of which they are well glued and strengthened. In the process of surfacing and rapid cooling, austenite breaks down with the release of fine carbides along the boundaries, which are ordered and lined up by a straight line under the influence of deformation.

Due to the development of deformation martensitic transformation in the weld metal, the indexes of the ability to harden at the level of alloys were obtained, in which this indicator was obtained due to the level of doping with the carbide-forming element (manganese and chromium), as well as the maximum index of the degree of hardening ∆. Strengthening is a great reserve for improving the reliability of parts. The presence of phase changes under the influence of plastic deformation in the weld metal is shown experimentally with the formation of deformation martensite. The combination of slander with deformation martensitic transformation effectively strengthens its base. Strengthening the micro-volume of the metal in the process of phase transformations increases its resistance to fracture, providing a more even distribution of plastic deformation, since the work involves non-reinforcing micro-volumes of the metal.