Five different alloy hardfacings on 16MnCr5 grade low-carbon ferritic–pearlitic steel were investigated in terms of their abrasive wear resistance in laboratory testing conditions. The selected hardfacing materials, namely “E520 RB”, “RD 571”, “LNM 420FM”, “E DUR 600”, and “Weartrode 62”, were individually deposited onto plain ground-finish surfaces of 10 mm thick steel plate samples. The studied hardfacings were fabricated using several different welding methods and process parameters proposed by their industrial manufacturers. In the present comparative study, the results obtained from laboratory abrasive wear tests of the investigated hardfacings were analyzed and discussed in relation to their microstructure, hardness, and wear mechanism characteristics. Regardless of great variety in microstructure and chemical composition of individual hardfacing materials, the results clearly indicated the governing factor for the wear resistance improvement to be the overall carbon content of the used hardfacing material. Thus it has been shown that the “E520 RB” hardfacing exhibited the highest abrasive wear resistance thanks to its appropriate hardness and beneficial “ledeburite-type” eutectic microstructure.
Tools for crushing of undesirable advance growth and mulching wood are subjected to heavy wear in operation with the need for their frequent replacement shortly after deployment. It is important to address the problem of their wear due to price of tools, as well as the time necessary for their replacement. Tool life is shortened because of deformation taking place due to the loss of wolfram-carbide (WC) tips, what is an undesirable phenomenon. Solutions for increasing the tool lifetimes were designed on the basis of analysis of wear mechanisms that cause this deformation. Furthermore, effect of deformed layer was evaluated by measuring hardness and microhardness. It was found that there was a strain hardening the surface due to cyclic loading. Size and extent of deformation of the entire tool with the loss of material on the functional part were documented using an optical scanning sensor system. Effect of the deformation on the material structure change, as well as topography and extent of surface area affected by abrasive wear under impact loads, were assessed by means of light and electron scanning microscopy. On the basis of these analyses, an option for increasing the lifetime of exposed areas on the tool by application of hardfacing to increase the tool wear resistance was proposed. Prerequisite for extending their work lifetime in the field is creation of a sufficient coarse layer or multiple layers of wear resistant material at specific tool areas.
The article deals with the influence of irregular tooth pitch on energy consumption of cross-cutting wood. In this article, the effect was assessed of feeding velocity and parameters of saw blade on the cutting power Pc of spruce (Picea Abies), pine (Pinus Sylvestris) and beech (Fagus Silvatica) wood during sawing with a guided circular saw. For the research, two types of circular saw blades were used, one of them having irregular tooth pitch. The circular saw blades had sintered carbide inserts with a diameter of D = 350 mm and the same number of teeth. The feed velocities were vf = 4, 8,12 m∙min-1 and revolutions n = 3000 min-1. The results showed that the circular saw blades with irregular tooth pitch have higher energy consumption than the circular saw blades with regular tooth pitch. The highest cutting power Pc was shown in the case of beech. It was also shown that energy consumption is increasing linearly with increasing feed velocity.
This paper presents a utilization of mulcher tools, their wear and possibilities of increasing their lifetime and durability based on analysis and tests. Mulcher tools are subjected to a very strong wear causing the loss of soldered WC tips in some cases and even permanent deformation of the body tool made of steel 14 220 (16MnCr5) during the continuous use. Images depicting the loss of material from the mulcher tool due to wear were produced by overlaying the pre- and after-wear tools by means of the optical scanning system. Input analyses - measuring of hardness, impact test and evaluating of microstructure showed that forging is without heat treatment. This does not provide sufficient mechanical properties to tools that would ensure work continuation after losing WC tips. Therefore, an appropriate process of heat treatment of the tool body has been proposed. By comparing the loss of material using abrasive test, it was observed that the wear of heat-treated material was three times lower than of material without heat treatment. This gives the precondition for increasing the resistance of the tool body and thus increasing of lifetime and durability after loss of WC tips. The implementation of such a solution could bring not only technical but also economic benefits.
The article is aimed at verifying the state of a real workplace using virtual reality. In analyzing the readiness of virtual reality applications, augmented reality was selected for the following work. The most significant advantage of augmented reality is the implementation of a virtual model and the ability to deal with the analysis in a real environment, which is particularly beneficial in the case of production plants. In the first phase of the work, an analysis of the current state of the workplace was carried out, where the requirements for the design of the new workplace were specified. This was followed by the phase of design preparation in 3D modeller. At this very stage it appeared to be advantageous to use virtual reality applications; in the design process, regular approval procedures are required as for an expert team (management, design, quality, ...), which puts high qualification requirements on the readiness of this team. In this phase, the 3D design of the new workplace was inserted into the application supported by augmented reality and some options were indicated to deal with the ergonomic and risk analysis. The result of this work is, in particular, an extension of options in designing and analyzing production workplaces and machinery in multidisciplinary teams.
Road maintenance and cleaning in winter are performed with ploughshares. Due to the fact that the layer of snow and ice that is removed from the road surface contains various hard impurities, ploughshares are exposed to high intensity abrasive wear. This article deals with the resistance to abrasive wear of originally used ploughshare materials and the materials that were designed as a suitable modification of the ploughshare to increase its service life. The chemical composition of materials used to manufacture ploughshare components is unknown. For this reason, they were analyzed with an ARL 4460 spectrometer, which was used to analyze the element content. The main part of the research was focused on the abrasion resistance test, which was performed according to the GOST 23.208-79 standard. Based on the chemical analysis, it was found that the basic body of the ploughshare was made of S355J2G3 steel, and the raking blade material was made of 37MnSi5 steel. The original material (steel S355J2G3) of the ploughshare body as a reference standard was compared to steel HARDOX 450. Furthermore, a sample made of the original material of the raking blade (steel 37MnSi5) was used as a reference standard, the properties of which were compared to the newly designed OK 84.58 and UTP 690 hardfacing materials. The parametric test method of statistical hypotheses was also used to process and evaluate the weight losses of the selected materials.
The article deals with the evaluation of interactions between abrasive particles and treated sample surfaces. It represents a summary of the knowledge gained from research the wear of tools for crushing unwanted growths. Samples of materials were tested under laboratory conditions. The hardness of HRC and HV10 was evaluated in the experiment, abrasive wear rate, assessed according to standard GOST 23.208-79. The depth of the track under test disc by using silicon abrasive particles was also evaluated. Furthermore, the hardness coefficient KT relative to the base material of the tool -16MnCr5 steel and the hardness of abrasive were determined. By comparing the measured and calculated values the heat treatment procedures and hardfacing materials were assessment. By comparing the measured and calculated values the heat treatment procedures and hardfacing materials were assessment, which are expected to provide an increase the abrasion resistance towards to an abrasive, heterogeneous working environment in operation.
Instruments working in the cultivation of forest areas, for example under the guidance of high stress, are exposed to factors of heterogeneous environment which are soil, wood, various types of rocks, sometimes waste -metal, plastics or glass as well. The mulching tool body, the forging, deforms and worsens rapidly after loss of the WC toe-caps. Currently used tools have a non-heat-treated body material with a ferritic-pearlitic structure that has low abrasion resistance. One of the possibilities is to heat the tool body. Another possibility is to apply suitable welds to exposed areas. By correctly selecting the thermal mode of the tool material or by applying the welded material to the exposed body part of the tool, we can ensure that the tool's operating time is increased.
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