Physical and Mechanical Aspects of Abrasive Wear of Steels in a Cooled Air Environment

Introduction. The relevance of the issues discussed in the paper is due to the strategy of development of economically promising regions of Russia, which are characterized by severe climatic conditions. This leads primarily to adverse effects on the material parts of the equipment operated by climatically low temperatures. Failure of parts and often assemblies is most often associated with its wear, which intensity, as a rule, increases when exposed to negative temperatures (low-temperature processes are usually attributed to processes occurring at temperatures below 273 K). The most destructive, in terms of the impact on the performance of these elements of mechanical systems, is its abrasive wear. At the same time, the practice of operation of equipment in Northern conditions showed that the intensity of this type of mechanical wear of parts in friction units is associated with an adverse effect on the physical and mechanical properties, and hence on the wear resistance of cooled air steels. Therefore, the study of the nature and causes of surface destruction of parts made of steel materials is of both scientific and purely practical interest. Ferrite-perlite is the basis for widely used steels (alloys) and in this context has become the subject of this study, associated with the goal: “to identify patterns of low-temperature abrasive wear of annealed carbon steels for its use in the development of evidence-based recommendations required in the design of high-wear resistance of metal materials”. This was part 1 of the study. Methods. In the scientific and applied research, both analytical methods and experimental wear tests on the installations of the original structures are used (protected by copyright certificates). The concept of kinematic pairs of the fifth class is used as a design model for the estimation of the trajectories and parameters of the sliding of the abrasive grains on the working surface of the accelerator (rotor). Results and discussion. Summarizing the results, it is necessary to note the following: First, the influence of the scheme of influence of abrasive particles on the wear surface of samples at low temperatures is experimentally recorded. Due to the concave (installation of the type of MCC) or convex (ring method) shape of the wear surface, the scheme of stresses on the destroyed surface of the sample is changed. This can be clearly seen on the wear curves in a cooled air. Secondly, the increase in the length of the interphase incoherent boundary in the system α-solid solution-hardening carbide phase (in the annealed state, carbon steels were tested in composition from pre-eutectoid to hypereutectoid) led to an increase in abrasive wear resistance over the entire range of the studied temperatures. At the same time, the indicated phenomenon has a number of features associated with a change in the wear mechanism when overcoming the threshold of cold fracture (from viscous to brittle).

abrasive wear, low-temperature air environment, steels, wear patterns, wear test schemes