International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In order to test the tribological properties of the high alloy ledeburite steel X210Cr12, test samples were made on which the mass loss was measured before and after the wear test. The test was performed using the “pin on disk” method on the Taber abraser device, with part of the samples tested without lubricant and part with lubricant to compare and present the results. X210Cr12 steel was chosen as the material for the pin sample, while low alloy steel was chosen for the disk sample. In the lubricant test, hemp oil was used and analyzed to show the effects of this oil on the lubrication and wear of the material. During the test, each sample was subjected to a modified load and a modified number of cycles. From the test results, it can be concluded that hemp oil exhibited satisfactory properties over all test cycles, with an approximately constant pattern of mass loss. In addition, hemp oil showed more favorable properties at higher test loads and a greater number of test cycles, so it can be used as a lubricant based on the test results obtained under test conditions such as those that prevailed in this test.

Mechanical wear, corrosion and erosion of the structural materials in machines and apparatus are destructive processes which cause worsening of their basic operational characteristics throughout their life cycle. As a result, the technological equipment undergoes loss of efficiency and reliability. It becomes unsafe from hygienic point of view. The expenses needed for its maintenance in crease significantly as the time passes. Its economical efficiency decreases as well. Materials which are in direct contact with food products can also transmit metallic ions or low molecular compounds to the processed food products – a process which is known as “migration”. Thin Layer Activation (also known as Surface Layer Activation) is an unique, efficient and innovative radiation based method used for conducting of comprehensive studies on surface degradation of materials. It allows real-time measurements of wear intensities with exceptionally high sensitivity within the scope of several ηm/h (or μg/h). The article reviews the essential principles of the Thin Layer Activation Method (TLA Method), describes its applications, capabilities and advantages. Possible uses in food processing industry are assessed and potential benefits from its implementation are discussed. Technological equipment in food processing industry includes machines and apparatus for production and processing of food products and liquids, packaging equipment, sanitation equipment, equipment for refrigeration and maintaining of certain environmental conditions, transportation equipment and auxiliary tools and equipment.

The features of structural changes in the cove zone on the tread of worn out railway wheels were investigated. The influence of laser processing in pulsed and continuous mode on the nature of the structure and properties of wheel steel was shown. The influence of laser treatment on the increase in the hardness and wear resistance of wheel steel has been established. It was shown possibility and necessity of local laser hardening of cove zone of railway wheels tread by coming out of bainite structure. A method for improving the wear resistance of the tread by local laser treatment has been proposed.

The paper presents the possibilities of renovation of worn functional surfaces of roll for continuous steel casting. The cylinder was made of steel 24CrMoV55 – DIN 17240. The lifetime of the continuous casting line roll is limited by the quality of their functional surface. The worn roll is decommissioned and the extent of its damage has been assessed. Cracks are a limiting factor in deciding on its renovation. Renovation of functional surfaces of roller from a diameter of ø 200 mm is realized by technology submerged arc welding (SAW). The article presents the results of research into the quality of newly formed cladding layers. Their quality was evaluated using non-destructive and destructive tests. Based on the performed experiments, it can be stated that the used surface renovation procedure is suitable for the renovation of functional surfaces of continuous steel casting rolls.

The article is devoted to the analysis of the most used additives for lubricants. The principle of their operation and the result of their work are considered. The effect of additives on the structure of surface layers on the surface of friction pairs is est imated. The analysis showed the use of only a limited number of principles of the action of antifriction additives. Theoretically promising antifriction additives for base oils, relevant for use in railway transport, have been proposed.

The article deals with the problem of wear of the train wheel crest and the conditions that affect the process of deformation of the material of the wheelset parts. Factors affecting wear are considered. It is shown that the resource of ridges depends on the nature and speed of chemical and physical processes. It was noted that in the center of destruction of the ridge, an increased content of carbon, oxygen and silicon was detected. It is established that the main way to reduce wear is to lubricate the comb in order to reduce the coefficient of friction.

The paper presents results of quality evaluation of hardfacing layers applied to functional parts of dredger teeth. Layers were made by arc welding methods MMAW and FCAW. High-alloy types of filler materials were used in the experiment. Their chemical composition allows the production of overlay layers with a high content of carbide particles. These particles ensure high resistance to abrasive wear of the layers. Excavator teeth were made by casting high-grade manganese steels Grade B-3 A 128 / A128M-93. In the experiments, the presence of surface defects of the weld deposit was assessed by visual inspection. The resistance of the hard-facing layers to the effects of abrasive wear was assessed using a Di-1 experimental apparatus and evaluated on the basis of weight loss.

The structure and physicomechanical characteristics of vacuum coatings formed from refractory metal compounds on steel substrates of different chemical composition are studied. The possibility of applying refractory metal coatings to protect metal substrates used for the manufacture of metalworking tools and steel tools used for casting non-ferrous metals has been analyzed.

The paper presents results of research of the essential characteristics of two kinds of advanced coatings applied by HVOF technology. One studied coating: WB-WC-Co (60-30-10%) contains two types of hard particles (WC and WB), the second coating is ecofriendly alternative to the previously used WC-based coatings, called “green carbides” with the composition WC-FeCrAl (85-15%). In green carbides coating the heavy metals (Co, Ni, NiCr) forming the binding matrix in conventional wear-resistant coatings are replaced by more environmentally friendly matrix based on FeCrAl alloy. On the coatings was carried out: metallographic analysis, measurement of thickness, micro-hardness, adhesion, resistance to thermal cyclic loading and adhesive, abrasive and erosive wear resistance. There were also determined corrosion characteristics of the coatings in NaCl and SAR solutions.

The paper presents the program and methodology of carrying out research on kinematic pair with pivoting friction. There was examined a node with pivoting friction in bearing concentrated connection flat surface-spherical bowl. During the research there were determined two types of characteristics – characteristic of friction moment as a function of load and experimentally designated characteristic of wear of the frictional kinematic pair. Both of the assigned characteristics are compared.

In this paper we have presented methodology for development of life prediction model for first order tool during turning of hardened 42CrMo4 steel at different levels of hardness. It is important to be able to predict and describe the tool life in regards to manufacturing costs during industrial production. Tool life is defined as the of cutting time that tool can be used. Cutting tools can be used when they do not reach tool life criteria and can produce parts with desired surface finish and dimensional accuracy. Flank wear of cutting tools is often selected as the tool life criterion because it determines the diametric accuracy of machining, its stability and reliability. Tool wear is defined as a gradual loss of tool material at contact zones of workpiece and tool material, resulting the cutting tool to reach its life limit. This paper investigates the tool wear of TiN coated tungsten carbide inserts under dry cutting, using the central composite design of experiments method (DoE) with three factors at three levels. By using the multiple linear regression analysis between cutting speed, feed rate and depth of cut, it determines the effects of cutting conditions on extended Taylor’s tool life equation.

The article deals with forming the adhesive bond of bodies at the crystal lattice level. There is offered a mathematical model for determining the adhesion wear. There are carried out laboratory tests for model validation. There is found that the amount of adhesive wear is nonline-arly dependent on the surface roughness inclination angle.