No abstract

This study examines the abrasive wear behavior of nano-sized steel scale on the CuZn35Ni2 Soft material. CuZn35Ni2 Soft material was used as a sample, and the three-body wear mechanism formed by nanoscale particles mixed with lubricating oil was investigated using a ball-on-flat tester. Three different loads, three different sliding speeds and three different environment variables were used in the experiments. A lubricant containing 0.15 and 0.3 wt.% nanoscale and a non-abrasive lubricant was used to form the medium. The experimental results were obtained as mass loss, wear depth and friction coefficient and the wear surfaces were examined using scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDX). The analysis of variance method was used to determine the effect of independent variables on the results. As a result of the study, it was concluded that the most effective parameter for mass loss and CoF was the environment, and the most effective parameter for the depth of wear was the load. It was concluded that there might be a difference of up to 10% in the coefficient of friction between the experiments and the predicted values. Still, in general, the predicted values and the experimental results agree.

In today's technology, the power of mechanization has emerged in places where manpower is insufficient in order to meet the increasing needs at many facilities. With belt conveyor systems, it has become much easier to transport the material from one site to another in the facilities in terms of time, distance, and capacity. Since belt conveyors are a reliable and cost-effective system in material handling, the quality of the belt used should be carefully determined. It is important that the wear and tear that occurs on the belt over time is repaired quickly and effectively in order not to prolong the downtime in the plant. A small damage detected needs to be repaired immediately so that it does not cause bigger problems. In this study, vulcanization time, which is one of the parameters affecting the belt strength in belt splice made by vulcanization method, is discussed. By studying the effect of time on belt strength, it is aimed to extend the life of the belt splicing area. According to the test results, it has been observed that the vulcanization time has a positive effect on the tape strength and the usage of welding machine saves time in terms of faster use of the tape in the facility.

The material S235JR was spray-coated with iron-based chromium carbide in the present study. The effects of the initial surface roughness on slurry erosion were investigated. Samples with a rough surface and polished surface were used. The impact of particle concentration, impact velocity and impact angle was studied on the slurry erosion characteristics in terms of mass loss, surface roughness and surface temperature. In addition, the surfaces were analysed using a scanning electron microscope (SEM). Further, the estimation equation has been derived using response surface method (RSM) based on the data obtained in the study. The results show that velocity and concentration are the key factors in determining the mass loss and surface temperature while the impact angle has a relatively minor role. Mass losses in rough samples ranged from 8.8 mg to 40 mg; in polished samples, the range ranged from 5.6 mg to 10.9 mg.

During a study of the combustion process of a direct polarity electric arc, a directly proportional dependence of the electric current value on the degree of cold plastic deformation of carbon steel used as an electrode was found. To calculate the value of the electric current during arc burning, in the indicated ratio, it was proposed to replace the surface tension force of the liquid metal with the surface tension of ferrite of plastically deformed carbon steel. Calculation of the ferrite’s surface tension value on the deformation degree of the steel under study through the size of the coherent scattering regions was used to explain the observed dependence of the electric current during arc burning. From the analysis of the considered correlation ratios, it was found that with an increase in the cold deformation degree, the refinement of the coherent scattering regions results in the ferrite’s surface tension increase and consequently, to an increase in the electric current during arc burning. Comparative analysis of the obtained results of calculating the value of electric current during arc burning through the surface tension of ferrite of cold-deformed carbon steel showed a fairly good coincidence with experimental data. The differences did not exceed 9%.