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Austenitic stainless steels are common spread in many industries. Plasma nitriding is one of the few technologies that allows surface modification of austenitic stainless steels. In this study, a plasma nitriding method to form a hard surface layer at two different austenitic steels AISI 302 and AISI 316L. The surface morphology, chemical composition and mechanical properties of the formed layers were described and the results were compared with each other. The formed nitrided layers on both steels created a uniform multi-phase layer which was characterized by high hardness and very good abrasion resistance.

Special attention is taking place in the environment of public transport, for which higher amount of small radius curves being applied is specific. The outcome of such operation of vehicles is an increase in vehicle's effects on the track in the rail-wheel contact resulting in increased ride resistance, creep in the rail-wheel contact patch, speeding up the process of wear in the contact pair as well as noise generation. At present, a variety of technical solutions for the vehicle bogie design as well as track designs focused on decreasing of these negative effects exists. Their use in smaller radius curves however, cannot give acceptable results and often causes complications in bogie design. The authors give a concept of creep reduction in rail-wheel contact by using double wheel tread, which doesn't require complicated bogie design. The proposed solution is supported by dynamical simulation of the tram car vehicle ride with considering of active wheel tread changes, and is also registered under Patent Application Nr. a201701589.

Contribution is focused on the analysis of power ratios on a drive shaft of a single-stage front gearbox and comparison of design solution of drive shaft using selected materials suitable for shaft production in terms of minimizing gearbox dimensions with respect to maintaining the transmitted power. The aim of the authors is to achieve the smallest possible dimensions of the gearbox shaft by changing the materials from which it is made.

The paper is part of the publication series, which describe the most significant and innovative research and development design solutions and computational procedures as part of European structural funds project. The object of this article is strength conditions assessment of a new structure of railway tank wagon. For validation of the new construction assemblies, there has been created a substitute simulation model. Results of calculations and prototype tests prove, that new structure of the construction satisfies strength assessments according to valid requirements and standards.

The surface quality of ceramic items produced via powder injection moulding (PIM) at processing conditions varying in injection moulding temperature and debinding route is investigated. The analysis is performed on aluminium oxide part design containing complicated rotational areas, where a smooth surface of an internal spiral is a critical quality factor. Surface properties of the final sintered parts are examined with the help of a contactless scanner. Then, the obtained surface roughness data are treated with suitable statistical analytical tools in order to reveal the effect of the processing conditions during the PIM process on the final parts. Relating surface properties of final sintered parts to processing parameters might provide a powerful tool to control particular steps of PIM process.

In the article the issue of perspective running parts for freight cars of new generation is considered and additions to the outdated existing classification of bogie are developed, namely introduction of such types of suspension is suggested.The results of theoretical studies are presented by means of modeling the movement of the car in the software "Universal Mechanism" to determine the influence of the first stage of spring suspension in Barber type bogie (type 18-100 and analogues) on energy efficiency (resistance to movement) and the estimated value of the decrease in resistance to movement.A concept for a fundamentally new design of a freight car bogie for high-speed traffic has been prepared, based on fundamentally new technical solutions with elastic-dissipative bearing elements, as well as a concept for the modernization of the Barber-type bogie (type 18-100 and analogues) by introducing axle suspension on the 1520 mm gauge.

Experimental studies of the wheel rim workpieces with additional technological corrugations have been carried out the results of which showed the ineffectiveness of this technique in profiling to increase thickness of the radial profile junctions of the semi-finished product. The comparison of profiling methods was carried out according to the Cochran's criterion and Student t-test. The additional experiments aimed at the determination of the flexural strain on differently shaped workpieces confirmed the impossibility of creation of the upthrust in the meridional direction during the deformation of the closed shells with straightening of the technological seats (corrugations). It is determined that the seats on the shell unbend in the tangential direction, the bending moments are damped nearthe site of the load application.

Design and technological development of cutting tools represents a fluent process that combines new knowledge from all usable technical branches with actual needs and development results of component base, production technology and machine tools. The main factors which nowadays accelerate the development of cutting tools are constantly increasing demands to improve efficiency and productivity while reducing operation costs, the application of hard machinable materials, environmental protection issues, health and growing demands for greater safety. The article deals with methodology of measurement and evaluation of cutting forces and cutting torque at a special reaming head MT3 from FINAL Tools Inc. Solution of force loading during reaming by these modern tools enable to analyse the causes of cutting tool deficiencies starting from coating suitability up to weaknesses in their design. The article also analyses the significance of the reaming process from the reaming view point using a process liquid, including a tool life analysis combined with the tool wear.

This paper deals with problem of brake elements unstable operation caused by temperature increase in the friction pair contact during braking. Analysis of constructive solutions for heat dissipation from the brake elements is carried out. It is known that the most used design of ventilated brake disks has disadvantage of creating resistance to movement, which reduces the power of the train. Methods and technical solutions for improving the braking system efficiency by stabilizing the friction contact temperature are investigated. Technical solution dealing with heat removing from the friction surfaces was proposed. Materials with phase transition is used in the design of the braking elements. The expert evaluation system software module in Microsoft Excel was developed to calculate the significance of methods for stabilizing temperature in the friction contact. The expert evaluation results of innovative methods for modern rolling stock brake systems efficiency increase are presented.

An article deals with the assessment of the heat treatment of the material for a particular machine component. This material is 34CrNiMo6, made of two melts. This steel belongs to a group of materials with special properties for working at higher temperatures and for the production of demanding components, turbine wheels, cardan shafts, toothed wheels. The material was evaluated for microstructure quality before and after heat treatment. Based on metallographic microstructures, it is possible to review the heat treatment mode, which subsequently affects the mechanical properties of the components. For a particular design element, better cast material was recommended based on a comprehensive evaluation.

The aim of the article is to verify dimensions of the hydraulic arm column (the necessary cross-sectional area) by analytical dimensional calculation and thus to design a lifting rotary arm which will be located on the pick-up car body (Figure 1). After the analysis of dimensions, the next step is creation of the structure in FEM program and then a numerical analysis will be carried out for verification of stress in the structure already with the values that are not available for the preliminary design (e.g. the structure weight). The next step in the solution will be to import the proposed and by strength calculations checked geometry into the multibody system program, where the dynamic response of the structure will be monitored, depending on the size of the load and the movement possibilities of this mechanism.

The paper deals with the design of a special machining tool for efficient production of detail on the T-groove of the clamping part. The introductory part of the paper is focused on introducing the Czech company. The practical part of the paper deals with the analysis of the existing state of machining of the clamping body and of the production of the T-groove detail and proposes an innovative solution in the form of more efficient machining process (partial production modification), which consists in the development and production of a special tool with replaceable inserts. The main reason for this partial modification is a significant reduction in unit machine time in the production of the T-groove detail on clamp body parts. Part of the contribution is in the process of streamlining the innovation made in the form of changes to the manufacturing process and the design of the cutting conditions required to produce the T-groove detail on the clamp body parts. The contribution is completed by a technical and economic evaluation, which is related to the analysis and comparison of both proposed production variants in terms of machine times, tool consumption / replaceable inserts and total production costs for the T-groove detail production on the clamp body parts.

The design of internal combustion engine use plain bearings, pistons and piston-rod which are based on aluminium, brass. Further are used steels with coating based on aluminium and bronze. The paper describes the impact of contaminants in motor oil on wear of materials, which are used in production of parts of internal combustion engine. Reichert tester M2 for evaluation the lubricity from Petrotest Company was used in order to assess ability of motor oils to create proper lubricating film. Reichert tester M2 belongs to a group of equipment simulating real frictional contact. Wear particles come into oil in lubrication system, where they cause contamination and degradation of lubricating properties and consequently it may result in major failure of machines. Among these contaminants are included mainly water, fuel, water coolant, adhesive, abrasive and fatigue particles wear. The aim of research was focused only on oil contaminated with fuel including petrol, diesel and biobutanol.

In the present study, local defects in deep groove ball bearings are studied as forward and inverse problems. To this end, the separation-integration method is applied for modeling the forward problem. It is assumed that the inner race of the rolling element is multi-DOF, while the outer race is deformable along the radial direction. Then the problem is modeled with concepts of the finite element method. The contact force for the rolling elements is described by the nonlinear Hertz contact deformation. Various surface defects originating from local deformations are introduced into the developed model. Since the outer ring can be coupled with the FE model of the housing, the developed bearing model is capable of considering the transmission path of the bearing housing. Then model parameters are modified to reach better performance in predicting local defects. Through translating the inverse problem into the comparison of the geometric distance, measured indicators are used in the defect detection process and the relative location and size of defects are predicted. Finally, the defect range is established to evaluate the fault severity. Obtained results demonstrate that the proposed method is effective and accurate in the studied cases.

The paper is focused on an analysis and optimization of the rotary draw benging process to eliminate bent tube ovality by modification of the pressure bar geometry. The bending process is realized on WafiosCNC bending machine. A tube that is bent for an automotive application is made of 34MnB5 steel. Currently, after tube bending process by an angle of 120°, an unacceptable ovality occurs. Therefore, it is necessary to improve the quality of production and thus prevent the formation of unacceptable ovality. In this case, the optimization of the pressure bar geometry is performed. For this reason, a numerical simulation using finite element method in ANSYS software is performed. Before the actual optimization, an accuracy of the simulation is verified by analysing of the current state and comparing it with simulation results.

This work discussed the corrosion behavior of the internal surface of pipeline steel caused by the composition of petroleum products, particularly crude oil. Internal and external pipeline corrosion is the notable cause of pipeline failure in Malaysia’s oil and gas industry. However, internal corrosion is preferred to be concerned in this work because it involved one of the major corrosive media in the crude oil, such as sulfur content. This project aim is to find the sulfur concentration in the crude oil using Fourier transform infrared spectroscopy and atomic absorption spectroscopy. The corrosion rate, corrosion current and corrosion potential of the API 5L X65 grade carbon steel pipeline in different simulated H2SO4 solution concentrations were carried out using the Tafel extrapolation technique. The corrosion properties of the samples were morphologically measured by means of optical microscope, scanning electron microscope and energy dispersive X-ray analyses. The results showed that the corrosion rate of the pipeline steel significantly increased with the increasing H2SO4 concentrations. The corrosion products formed on the pipeline steel surfaces were mainly composed of iron sulfate, iron sulfide and iron oxide. These findings are crucial to understanding the corrosion behavior caused by the crude oil and should be further investigate with the other possible influence factors such as temperature and petroleum’s flowing velocity.

In the performed experiment, changes in the microstructure of steels S265 and X6CrNiTi18-10 due to their chemical-thermal treatment by boriding were studied. The boriding process was performed in a Durborid boriding powder at 900 0C. During this process, surface layers of Fe-B borides were formed in both analyzed sorts of steels. The layers differed in their morphology and composition due to the different degree of alloying of the matrix of analyzed steels by additive elements. The formed Fe-B layers showed high adhesive and cohesive resistance in both materials. Due to changes in the micro-structure of S265 steel, especially due to significant coarsening of the original grain of its matrix, its resistance to tribological abrasion after the boriding process decreased. The opposite effect was ob-served for X6CrNiTi18-10 steels. As a result of boriding, both analyzed materials changed their corro-sion resistance.

The aim of this paper is an analysis of the dependability of critical components of the John Deer 7530 tractor. For this analysis data was used from a database which contains maintenance data of 166 trac-tors during approx 9 years. The first part of this article is devoted to the selection of critical compo-nents based on number of failures of individual machine parts for a given period and their sales pric-es. The next part of article presents data for calculation dependability indicators which contains oper-ating times to failure and operating times without failure. Due to the large size of the data files of the individual components, the data are only given for one machine component. Furthermore, the meth-od of calculation of dependability indicators is described by parametric statistical methods according to ČSN EN 61649:2009 and mean time to operating failure. The results of the analysis are summa-rized in tables and graphs. The method in this article can be used to optimise the maintenance pro-gram.

In order to improve the transmission efficiency and the service life of ordinary cycloid gear, 5 kinds of new cycloid gears with variable cross section are devoleped based on the principles of traditional cycloid drive. These new cycloid gears include concave cycloid gear, drum cycloid gear, spherical cycloid gear, oblique cycloid gear and cone cycloid gear. The general mathematical equations of these new cycloid gears are obtained and the characteristics of these new cycloid gears in transmission applications are analyzed in detail. A new method on the end milling tooth profile surfaces of cycloid gear using ball end mill is proposed. 5 axis numerical control simulations of these cycloid gears are conducted and the tool paths of machining cycloid gear are obtained. 5 kinds of cycloid gear with variable section are machined on five-axis CNC machining center, which verifies the correctness of the NC program. The study will provide a new way of designing and machining cycloid gear.

The work is focused effect of different temperature nozzle in additive manufacturing process FFF (Fused Fila-ment Fabrication) technology for the most common materials (PLA, PETG and ABS). A standard specimen internal structure arranged ±45° in longitudinal print direction with 100% infill. For the exact testing are used no perimetres. The specimens were printed by minimal, middle and maximum nozzle tem-perature. Temperature range is given by the filament company. To ensure relevant testing materials from the same company in one colour were used. A printed specimens were testing by destructive testing method on tensile testing machine. For testing were made five specimens in one setting. Finally, were made 45 specimens for tensile testing.

Metal machining is a complex technological process based on material removel from semi-product by the influence of a cutting tool which is abrasion-resistant at high mechanic and heat strain. The essence of material removal is based on considerable material plastic deformation under the tool cutting wedge, the result of which is a deformed chip and transformed workpiece surface, which must comply with the geometrical and mechanical workpiece characteristics. These are determined by selected cutting conditions, geometrical and mechanical characteristics of the cutting tool. The selection of cutting conditions is engineering art and requires deep knowledge of machining process, mainly the relationship between cutting conditions and ther results of machining. These relationships are being tried to identified in the paper.

This experiment assesses the suitability of square-welding high strength steel using the deep penetra-tion welding method, RapidWeld. The aim of this method suitability assessment was to compare the final material properties of three welds, welded accordingly to identical welding procedures. High strength, ultra-fine-grain steel S1100QL (XABO 1100) was used as a parent metal. The suitability con-firmation was based on the achievement of requested mechanical properties of ISO 15614-1 and mo-bile crane manufactures standards. The hardness, strength properties and impact energy measure-ment and evaluatioon of the joint was performed during the experiment. The joint was welded re-peatedly with the use of the same welding parameters for the confirmation of process stability. The achieved mechanical properties fulfill all the requirements. The hardness value deviation is caused by different properties in the heat affected zone. The root cause of the impact energy deviaton was not fully investigated, but the minimal measured values are above requirement. The deviation of the strength characteristics is mininal. The performed experiment has confirmed that the selected weld-ing method is suitable to ensure that the requested material properties of welded high strength, ultra-fine-grained steel are achieved.

Taking the discrete degree of bearing raceway grinding surface integrity as the research object, the orthogonal test based on the wheel speed, workpiece speed and grinding depth is designed. The residual stress, retained austenite, hardness, grinding modified layer thickness and roughness of the raceway after grinding test were measured, and the mean value and standard deviation of these indexes were calculated. The results show that the standard deviation of residual stress and roughness decreases with the increase of wheel speed, and the standard deviation of retained austenite, hardness and grinding modified layer thickness keeps stable. Finally, the optimal grinding parameters considering the scatter of surface integrity are selected.

In this paper, innovative resistance element welding (REW) technology for joining galvanized steel sheets to thermoplastics (PMMA) is introduced. The essence of the innovation is in the use of a special bimetallic joining element consisting of the core made of a Sn60Pb solder, and the sleeve made of a Cu tube. During resistance heating, the solder melts, thus allowing the formation of a metallurgical joint with galvanized steel sheet. Since Sn60Pb solder melting occurs at temperatures (from 183 to 190 °C) be-low the thermal decomposition temperature of most thermoplastics (for PMMA above 300 °C), there is no thermal destruction of the PMMA material around the joint. The mechanical fixation of the thermo-plastic material at the overlap joint is provided by the sleeve made of Cu tube which has a substantially higher strength than a Sn60Pb solder.

Presented article deals with designing of the novel technology for repairing of the defects in branch connections of the gas pipelines. Until now, defects of the branch connections could be repaired mainly by replacing of the damaged area, especially those allied with gas leakage. The most important requirement of new type of repairing technology is maximal allowable operational pressure, which has to be the same as for repaired pipeline. Dimensions of the split sleeve should be thus designed according to required pressure value. In the case of split sleeve for branch connections, dimensions were determined by the static analysis in ANSYS software. Designed sleeve was after manufacturing process subjected to pressure testing by standardised test to confirm requirements of the standards. Pressure test to destruction was performed in order to determine the weakest place of construction. Proposed repairing solution might lead to reducing of the costs for performing of the branch connections repairs.

A new Coupler Critical Dimensions (CCD) approach to define mobility criteria (crank, rocker conditions, or existence) for linkage mechanisms has been presented in this paper. The idea is to analyze the extreme lengths of a mechanism coupler link when the mechanism is on the extreme of its existence or changing its mobility condition. The method leads a set of expressions of the constant mechanism parameters that can be used to define the exact dimensional limits of the coupler link in the mechanism. These expressions present sufficient and necessary dimensional conditions for the mechanism existence and become a turning point to change its mobility from crank to a rocker and vice versa. At the boundaries of the coupler dimensions, the mechanism reaches its the change-point configuration where the mechanism may switch either from one work function to another or from existence to non-existence. The method has been successfully applied to the planar 4R, spatial RSSR, and planar multiloop linkage mechanisms. The obtained results prove the effectiveness and accuracy of the method in defining the limits of the mechanism rotatability conditions or existence in general.

Increasing the efficiency of cutting operations while fulfilling the required (expected) quality of the parts constantly requires a thorough knowledge of the chip removal process. This is especially justi-fied in the case of deviations from the usual (traditional) technological conditions or cutting data, both in terms of cutting theory and technique. This paper summarizes some of the results of a study of cutting force and cutting temperature in face milling. The technological analysis of face milling was performed by FEM simulation, which was compared and validated by measuring the cutting force. The chip removal of C45 rolled steel as a function of tool rotation was studied with two differ-ent depths of cut ap and feed rate fz so that at a constant nominal Ac cross section the ratios ap/fz were 0.1 and 10. The effect of the change of the cross-section and chip ratio is shown.

The current study investigates the influence of the dressing process of the vitrified bonded microcrystal alumina grinding wheel on the roughness of the machined surfaces in cylindrical grinding of Ti6Al4V alloy using different types of stationary diamond dressing tools. For the research, four types of dressers were selected, which differ from each other by number, size and location of diamond cutting elements. Each dresser has been tested at four different dressing feed values with the same dressing depth. Two sets of experiments were conducted to determine the tendency of grinded parts roughness parameters change depending on the dressing feed for each type of diamond dressing tool at two values of grinding feed. A comparative analysis was carried out to show the dressing feed influence and the effect of the diamond dresser type select on the roughness parameters of the grinded surfaces.

With the rapid development of modern manufacturing technology, people have higher and higher requirements for the quality of mechanical products, and the precision of machine tools for processing mechanical products has gradually increased. Therefore, the development of static pressure guides is particularly important for precision processing industries. The load on the guide rail has an important effect on the thickness of the oil film, and the stability of the oil film thickness directly determines the accuracy of processing. In order to obtain the best control method for the thickness of the oil film, the dimensions of the hydrostatic guide rails and the three-dimensional model of the guide rails were designed and calculated in this paper, and the fuel supply method of the guide rails was determined. The simulation model of the oil film was established and imported from the AMESim software into the FLUENT software to obtain the pressure, velocity, and temperature distribution maps of the oil film. And the pressure distribution data was processed after summarizing. Combined with the relevant mathematical models, the mathematical model of the oil film thickness was finally obtained. Then the Simulink software was used to analyze and the PID control was introduced for comparative analysis. The DOB anti-interference control theory was introduced, and the anti-interference control algorithm was improved. The anti-interference algorithm adapted to the oil film thickness control complete the programming of the modules of the interference controller. The anti-interference control section was created in the Simulink software, and the system of the DOB module was finally completed after packaging. In order to verify the method in t his paper, a static pressure rail test bench was set up, and relevant detection tests were completed. The results of the above studies showed that the control performance was greatly improved after introducing the anti-interference algorithm adapted to the oil film control system.

The article concerns the testing two thin-walled fiberglass materials. The aim of this work was to perform tensile tests at room temperature in order to determine the stress-relative deformation dependence in selected directions and to compare the properties of each individual material in these directions. Characteristics determined in this way are to be used as inputs in simulation models forming a part of the process of validating the dummy model’s behaviour in simulations of collisions of the tram front with a pedestrian. Tests have been conducted of such properties of those materials used for external panelling of 15T and T3 tram fronts. The knowledge of these properties is crucial in terms of the mentioned validation. The output of the measurement includes tensile diagrams, including the evaluation of the ultimate tensile strength, elastic modulus and relative elongation at the ultimate tensile strength. Also, the conversion of the elastic modulus for the fibreglass with a different fibre volume part is presented.