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1

Development and implementation of robotized wire arc additive repair of a gas turbine diaphragm

Steckowicz Piotr, Pyrzanowski Paweł, Bulut Efe

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 2

art. no. e147920

EN

The current practice of reconstruction of oxidized turbine parts (due to hot corrosion) using arc welding methods facilitates restoration of the nominal shapes and dimensions, as well as other attributes and features. Intense development of 3D additive methods and techniques contributes to the repair/modification of different parts including gas turbine (GT) hardware. The article proves the viability of the concept of using a robotized additive arc welding metal active gas (MAG) process to repair and modify gas turbine diaphragms using different filler materials from the substrate. The industrialized robotic additive process (hybrid repair) shows that very good results were achieved if the diaphragm is cast of nickel-iron and the filler material for welding the passes is austenitic stainless steel (for instance 308 LSi). This is one of the novelties introduced to the repair process that was granted a patent (US11148235B2) and is already implemented in General Electric Service Centers.

2

Design and Implementation of a Versatile Flexible 3D Wire Bending Machine with Accuracy Algorithm

Farhan Mohammed O., Al-Khafaji Muhannad M.H., Abood Muhannad Q.

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

244--254

EN

This Paper presents the development of a flexible wire bending machine designed to overcome limitations associated with traditional counterparts. Traditionally, wire bending machines are often designed for specific purposes, necessitate complex coding, are prohibitively expensive, or are constrained to producing two-dimensional shapes. To address these challenges, our study begins with an extensive review of existing research in the field, followed by the selection of a concept derived from this analysis. The methodology encompasses the entire design and manufacturing process. Initial research guides the concept selection, which is then translated into a practical design using SolidWorks simulations. The theoretical foundation involves mathematical formulations for each machine component, ranging from the wire feeding system to the bidirectional and 3D bending mechanisms. Main actuators are chosen based on calculated parameters, and the machine is assembled, incorporating a CNC system. The machine is tested first without wire and subsequently with the bending of an aluminum (1350-H26), 3.2mm diameter wire, copper with 3.25 mm diameter and steel with 2.5 mm diameter. The Results demonstrate high accuracy performance and underscore the significance of considering spring back and bend allowance for precision in both 2D and 3D wire configurations. This study not only contributes to the design and fabrication of a flexible wire bending machine but also addresses the shortcomings of traditional counterparts, making wire bending more accessible, versatile, and cost-effective.

3

Analysis of Wire Rolling Processes Using Convolutional Neural Networks

Capelin Matheus, Martinez Gustavo A.S., Xin Yutao, Siqueira Adriano F., Qian Wei-Liang

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

103--114

EN

This study leverages machine learning to analyze the cross-sectional profiles of materials subjected to wire-rolling processes, focusing on the specific stages of these processes and the characteristics of the resulting microstructural profiles. The convolutional neural network (CNN), a potent tool for visual feature analysis and learning, is utilized to explore the properties and impacts of the cold plastic deformation technique. Specifically, CNNs are constructed and trained using 6400 image segments, each with a resolution of 120x90 pixels. The chosen architecture incorporates convolutional layers intercalated with polling layers and the “relu” activation function. The results, intriguingly, are derived from the observation of only a minuscule cropped fraction of the material’s cross-sectional profile. Following calibration and training of two distinct neural networks, we achieve training and validation accuracies of 97.4%/97% and 79%/75%, respectively. These accuracies correspond to identifying the cropped image’s location and the number of passes applied to the material. Further improvements in accuracy are reported upon integrating the two networks using a multiple-output setup, with the overall training and validation accuracies slightly increasing to 98.9%/79.4% and 94.6%/78.1%, respectively, for the two features. The study emphasizes the pivotal role of specific architectural elements, such as the rescaling parameter of the augmentation process, in attaining a satisfactory prediction rate. Lastly, we delve into the potential implications of our findings, which shed light on the potential of machine learning techniques in refining our understanding of wire-rolling processes and guiding the development of more efficient and sustainable manufacturing practices.

4

Coaxial Laser Wire Deposition of AISI 316L steel - research on influence of processing parameters

Koruba Piotr, Radkiewicz Przemysław, Kędzia Jakub, Dziedzic Robert, Smuga Piotr, Reiner Jacek

Welding Technology Review

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2023

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R. 95

67--77

EN

Laser cladding technology is a well-established process, commonly used for deposition of improved-property coatings, repair of machine parts and additive manufacturing. Currently, in terms of application of laser cladding, the method based on powder deposition is much more common, as the use of an adapted nozzle allows the coaxial and direction-independent feeding of additional material into the weld pool. However, laser cladding with powder also has some significant drawbacks, e.g., limited powder feeding and melting efficiency, lower productivity and the resulting dust that poses a health risk to operators. The solution to these limitations is the use of additional material in the form of wire. To maintain the ability to coaxially feed the wire to the laser beam interaction point, a specialized cladding head is necessary. In mentioned system the laser beam, while being passed through the optical system, is divided into three separate beams that are focused on the substrate on the working point of the head. In this study, the COAX wire cladding head was integrated into the robot station and laser cladding process was carried out to determine the influence of the processing parameters on the deposition results. The parameters of the cladding system were identified, including the measurement of laser beam caustic. The experimental trials were carried out using AISI 316L wire deposited on S420MC substrate. The effect of the processing parameters on the geometry of the clad was determined with particular emphasis on the wire feeding.

5

Określenie wpływu konstrukcji zabudowy na nagrzewanie bezhalogenkowych przewodów elektrycznych

Perka Bogdan, Suproniuk Marek, Piwowarski Karol, Paziewski Piotr, Kaczmarek Witold

Przegląd Elektrotechniczny

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2023

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R. 99, nr 1

203--206

PL

Artykuł opisuje badania zjawisk wymiany ciepła pomiędzy otoczeniem, a przewodem elektrycznym podczas warunków termicznych przekraczających wartości dopuszczalne, dla powszechnie stosowanych przewodów elektrycznych niepalnych. Podjęto próbę wyznaczenia podstawowych parametrów cieplnofizycznych dla przewodu elektrycznego jako jednego układu fizycznego złożonego z żyły przewodzącej, izolacji żyły, izolacji zewnętrznej przewodu. Do budowy modelu przewodzenia ciepła przez przewód elektryczny, wykorzystane zostały dane pomiarowe uzyskane z zaprojektowanego eksperymentu dla trzech przypadków zabudowy przewodu: w otwartym korycie kablowym, w izolacji termicznej (PUR) oraz w zamkniętym kanale kablowym (light concrete). Do zamodelowania przepływu ciepła wykorzystano metodę analogii układów cieplnych i elektrycznych. Model matematyczny jest równaniem linii długiej (linia Kelwina – Thompsona) opisana parametrami rozproszonymi co stanowi własny wkład naukowy autorów w badanie zjawisk cieplnych w przewodach elektrycznych.

EN

The article describes the study of the heat exchange phenomena between the environment and the electric conductor during thermal conditions exceeding the permissible values for commonly used non-flammable electric cables. An attempt was made to determine the basic thermophysical parameters for an electric conductor as one physical system consisting of a conductor, conductor insulation, and outer insulation of the conductor. To build a model of heat conduction through an electric cable, the measurement data obtained from the designed experiment for three cases of cable installation were used: in an open cable tray, in thermal insulation (PUR) and in a closed cable channel (light concrete). The method of analogy of thermal and electrical systems was used to model the heat flow. The mathematical model is an equation of a long line (Kelvin - Thompson line) described with dispersed parameters, which is the authors' own scientific contribution to the study of thermal phenomena in electrical cables.

6

Influence of anisotropy of mechanical properties on hydrogen induced cracking

Kukołowicz Łukasz, Oleszak Dariusz

Ochrona przed Korozją

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2023

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nr 2

38--43

EN

Hydrogen induced cracking is a form of wet H2S cracking. Blistering or crack propagation is a result of the mechanical tearing of material by high-pressure hydrogen gas forming on internal material discontinuities, like non-metallic inclusions. This failure mechanism is typically associated with low and medium-strength pipeline steels, however, it does also occur in high-strength rolled wire. This evaluation aims to elucidate the mechanism of this susceptibility. The characteristic failure pattern where cracking occurs near the wire centreline and propagates perpendicular to the rolling direction leads to believe that the wire anisotropy, developed during cold rolling, plays a critical role. A mechanical property – flow resistance in principal directions – was measured using the Wheeler and Ireland technique. It was found that the “weak” direction is perpendicular to the crack propagation direction. The failure rate does not correspond to the flow resistance, but rather to the flow resistance ratios. It is proposed that those ratios are not only a measure of anisotropy but also a measure of microstructural damage inflicted by the cold rolling process. This microstructural damage is partially reversible by heat treatment processes.

PL

Pękanie wodorowe jest mechanizmem degradacji często zachodzącym w środowiskach korozyjnych, w których występuje siarkowodór. Propagacja pęknięć postępuje na skutek fizycznego rozrywania materiału przez cząsteczkowy wodór pod wysokim ciśnieniem, tworzący się na nieciągłościach wewnętrznych, takich jak na przykład wtrącenia niemetaliczne. Praca badawcza dotyczy mechanizmu pękania wysoko wytrzymałego kształtowego drutu stalowego. Drut pęka w charakterystyczny sposób: pęknięcie tworzy się w pobliżu środka drutu i propaguje równolegle do płaskich powierzchni. Obserwacja ta każe przypuszczać, że propagacja związana jest z anizotropią właściwości mechanicznych drutu. Anizotropię zbadano jako opór płynięcia plastycznego materiału pod wgłębnikiem twardościomierza metodą Wheelera i Irelanda. Zaobserwowano, że pęknięcia propagują prostopadle do kierunku, w którym występuje najmniejszy opór płynięcia. Pękanie podczas testów w środowisku korozyjnym z siarkowodorem nie jest skorelowane bezpośrednio z oporem płynięcia, a ze stosunkiem oporów płynięcia w dwu kierunkach, a więc miarą anizotropii. Z badań wynika, że proces walcowania na zimno powoduje uszkodzenia mikrostruktury, które można szacować miarą anizotropii właściwości mechanicznych drutu i które są częściowo odwracalne w procesie obróbki cieplnej.

7

Środowiskowe aspekty obróbki elektroerozyjnej

Tadeusz Leppert

Obróbka Metalu

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2023

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nr 4

34--43

PL

Obróbka elektroerozyjna (Electro-Discharge Machining . EDM) jest jednym z najbardziej rozpowszechnionych sposobów niekonwencjonalnego kształtowania przedmiotów, stosowanym do obróbki powierzchni o złożonych kształtach, zwłaszcza materiałów o dużej twardości i trudno skrawalnych. Z tego powodu zrozumiałe jest dążenie do zwiększania efektywności tej obróbki. Z drugiej strony, rosnące zainteresowanie wpływem ogółu procesów produkcyjnych na środowisko naturalne i zdrowie pracowników, spowodowało zintensyfikowanie badań zmierzających do opracowania nowych lub zmodyfikowanych sposobów obróbki EDM zmniejszających lub eliminujących ich negatywne oddziaływania środowiskowe. W artykule przedstawiono analizę czynników procesu drążenia elektroerozyjnego będących źródłem zagrożeń środowiskowych. Scharakteryzowano także podejmowane próby ich ograniczenia z zastosowaniem innowacyjnych rozwiązań technologicznych obróbki elektroerozyjnej.

EN

Electro-Discharge Machining (EDM) is one of the most common methods of unconventional forming of objects, used for surface treatment of complex shapes, especially materials with high hardness and difficult to machine. For this reason, it is understandable to seek to increase the efficiency of this treatment. On the other hand, the growing interest in the environmental and health impacts of production processes in general has led to an intensification of research into new or modified EDM treatments to reduce or eliminate their negative environmental impacts. In this paper there were presented an analysis of the EDM factors generating environmental risks and characterizes the attempts to limit their negative influence by introducing innovative EDM technologies.

8

Fatigue life of compacted wire ropes for applications in deep mining

Kubiś Bogusław, Olszyna Grzegorz, Szade Piotr, Tytko Andrzej

Management Systems in Production Engineering

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2023

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nr 1 (31)

95--101

EN

Recent months have highlighted the progressing energy crisis across Europe in connection with the severe sanctions imposed on the import of hydrocarbons and coal from Russia. This is particularly visible in Poland, where over 40% of electricity is generated from coal, while in individual households it is the primary source of heat. This situation puts the already enigmatic plans of shutting down coal mining in Poland into question. Therefore, work aimed at increasing the extraction capacity of existing shafts while maintaining the highest level of operational safety is still valid. This article concerns the issues of the fatigue life of compacted ropes used as hoist ropes in mine shafts. The discussion regarding the use of these ropes among shaft hoist users has been going on for several years. This paper presents the unique results of compacted rope fatigue tests carried out at the Central Mining Institute in Katowice. In the authors’ view, these results and their interpretation should serve to clarify several important aspects that arouse the interest of users.

9

Establishment of constitutive model and dynamic parameter analysis of rubber conveyor belt

Chen Hongyue, Liu Siyuan

Journal of Theoretical and Applied Mechanics

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2023

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Vol. 61 nr 2

365--378

EN

A rubber conveyor belt is an essential piece of equipment in coal mine transportation. Its current motion and performance are directly affected by dynamic parameters. In this paper, a constitutive model has been established to study a rubber conveyor belt in order to analyze its dynamic characteristics. The covered rubber was considered as a classical solid model. The wire rope core was used as a Kelvin model, and a generalized constitutive mathematical model was established. Using Matlab, compariso of the fitting curve and the experimental curve was carried out to ensure reliability in an appropriate way. Meanwhile, the influence of different factors on dynamic parameters of rubber conveyor belts was also discussed by controlling the loading frequency and amplitude as well as external temperature. Finally, the experiment with the fitting curve was compared and verified, and the research results can provide a reference for this engineering field.

10

Multi-objective optimization for weld track geometry in wire-arc directed energy deposition of ER308L stainless steel

Nguyen Van Canh, Le Van Thao, Pham Ngoc-Linh, Nguyen Anh-Thang

Journal of Machine Engineering

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2023

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Vol. 23, No. 2

123--134

EN

In this research, the weld track geometry in wire-arc DED (directed energy deposition) of ER308L stainless steel was predicted and optimized. The studied geometrical attributes of weld tracks include weld track width (WTW), weld track height (WTH), and contact angle (α). The experiment was designed based on Taguchi method with three variables (current I, voltage U, and weld velocity v) and four levels for each variable. The ANOVA was adopted to evaluate the accuracy of the models and impact levels of variables on the responses. The TOPSIS method was utilized to predict the optimal variables. The results indicated that the predicted models were built with high accuracy levels (R2 = 98.92%, 98.77%, and 98.91% for WTW, WTH, and α, respectively). Among the studied variables, U features the highest effects on WTW and α with 78.56% and 69.90% of contribution, respectively, while v is the variable that has the most impact on WTH with 39.82% of contribution. The optimal variables predicted by TOPSIS were U = 23 V, I = 140 A, and v = 300 mm/min, which allows building components with stable and regular geometry.

11

Research on New Al-Ag-Mo Alloys Dedicated to Wire Applications in Overhead Power Lines

Grzebinoga Justyna, Mamala Andrzej, Ściężor Wojciech, Kowal Radosław

Journal of Casting & Materials Engineering

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2023

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Vol. 7, no. 1

9--14

EN

The latest research work in the field of electric power systems focuses on the development of new wire materials which will allow the increase of the transmission capacity of power lines currently in use. The reason for this research was the often limited possibilities of continuous and failure-free transmission of electricity. In this paper, the authors present research on a new aluminium-based alloy dedicated for use as a conductive braid in the HTLS cable group. There are many technical solutions for this group of cables on the market, although they are solutions with a number of disadvantages, ranging from their high price, various operational shortcomings, complicated installation techniques, and ending with the risk of monopolistic practices, which is related to the inability to attract several competitive suppliers. The main aim of the research was to develop a new alloy based on aluminium with the addition of silver and molybdenum dedicated for use in special overhead power cables. Experimental research on new materials focused on obtaining the necessary knowledge to produce an overhead wire from these alloys with higher current carrying capacity in relation to the currently used conventional wire materials based on aluminium.

12

Rola izolacji technicznych w zapewnieniu standardu akustycznego

Ryńska Joanna

Izolacje

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2023

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T. 28, nr 11/12

96--98

PL

Izolacje techniczne często omawiane są przede wszystkim pod kątem parametrów cieplnych. Warto jednak pamiętać także o ich innych funkcjach, np. o izolowaniu akustycznym. Własności akustyczne instalacji HVAC czy sanitarnych zyskują coraz większe znaczenie, gdy mowa o standardzie budynków albo poszczególnych lokali w kontekście odpowiedniego komfortu czy rosnących wymagań użytkowników.

13

Comparison of the stiffness of 3D-printed wire raceway slewing bearing based on simplified FEA model and experiment

Gunia Dominik, Smolnicki Tadeusz, Stańco Mariusz

Engineering Transactions

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2023

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Vol. 71, iss. 3

383--397

EN

The wire-raceway bearings are a subcategory of slewing bearings. Their popularity has recently increased due to their advantages, including weight that is lower than that of other similar slewing bearings, and the ability of transferring various loads, such as axial load, radial load and tilting moment. Currently, metal rings (steel or aluminum) are the most popular choice for all kinds of slewing bearings; however, with advent of additive manufacturing a new ‘chapter’ opens for the development of wire raceway slewing bearings, where the interface between the rolling elements and the raceway is the same as in other bearings (i.e., contact between steel-steel). At the same time, rings can be made from other lightweight materials, such as composites or plastics, with high-level shape customization due to 3D printing. Stress between wire raceways and rings is much lower. Hence, rings’ lower material properties do not significantly affect bearing capacity. Proper calculation methodology should be created to analyze lightweight wire raceway bearings, as materials can differ significantly from typical materials covered by current theories. The paper presents a prototyped 3D-printed bearing with rings made from polylactic acid (PLA). The bearing stiffness is measured and compared with the simplified finite element analysis (FEA) model using the equivalent bearing model with nonlinear springs and beam elements.

14

Physical and numerical simulation of the production chain of fasteners manufactured of 32CrB4 steel control-cooled in the stelmor process to develop the multiphase microstructure

Piwowarczyk Michał, Wolańska Natalia, Wilkus Marek, Pietrzyk Maciej, Rauch Łukasz, Kuziak Roman, Pidvysots’kyy Valeriy, Radwański Krzysztof

Computer Methods in Materials Science

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2023

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Vol. 23, No. 2

5--16

EN

The development of the concept of Thermomechanical Controlled Processing (TMCP) in the wire rod rolling mill of CMC Poland has opened up new opportunities for the production of fasteners without the application of heat treatment. The crucial effect of TMCP in the case of wire rod rolling is its capability of shaping fine austenite grain size following the last pass, typically below 20–25 µm in the wire rod cross-section. This is a prerequisite for obtaining the required cold workability level for the cold forming of fasteners, even if hard constituents (bainite, martensite) are present in the wire rod structure. In this paper, the physical simulation and numerical modelling capabilities were described for the design of cooling conditions in the Stelmor process and cold heading operation. The investigated material was conventional 32CrB4 grade used for the fasteners production with the application of heat treatment.

15

WEDM parametric study of AA7075/6 wt.% Ni-COATED Al2O3(P) composite miniature GEARS

Praveen D.V., Raju M.V.J., Raju D.R.

Composites Theory and Practice

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2023

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R. 23, nr 2

89--96

EN

Nowadays, gears are essential components in various electro-mechanical devices. Nevertheless, the fabrication of miniature-sized gears is very complicated. The present paper is focused on assessing the influence of the WEDM parameters on the material removal rate (MRR) and surface roughness (Ra) of AA7075/6 wt.% nickel-coated Al2O3 composite miniature gears. Initially, the theoretical design calculations were performed, and consequently the results were validated using ANSYS 19.0 software. Furthermore, experiments were modelled in accordance with Taguchi’s L9 orthogonal array. Optimal combinations of pulse on time, pulse off time and peak current were assessed using grey relational analysis (GRA) coupled with principal component analysis (PCA). The significance of the parametric influence on the machining responses was also evaluated using the ANOVA technique. Consequently, confirmation tests were conducted to verify the optimal parameters and the predicted results are in good agreement with the experimental findings.

16

Możliwości i ograniczenia magnetycznej metody MRT badania stanu technicznego lin stalowych w czasie ich eksploatacji na urządzeniach dźwignicowych

Martyna Maciej, Martyna Roman

Badania Nieniszczące i Diagnostyka

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2023

|

nr 1-4

48--55

PL

Liny stalowe są najsłabszymi elementami urządzeń linowych, w czasie eksploatacji druty lin ulegają degradacji spowodowanej zmęczeniem materiału przy wielokrotnym przeginaniu, powierzchniowym starciom, korozji i uszkodzeniom mechanicznym. Okres użytkowania lin jest krótszy niż urządzenia linowego na którym są zainstalowane. O konieczności odłożenia liny z eksploatacji decyduje najbardziej zużyty odcinek. Do tej pory szeroko stosowane i standaryzowane badania niszczące określające ABL (Actual Breaking Load) jak i inspekcja wizualna VT (Visual Testing) lin stalowych nie dają zadowalających rezultatów, a przy zastosowaniu nowoczesnych wielowarstwowych kompaktowanych konstrukcji lin o dużych średnicach nie pozwalają wykryć degradacji zmęczeniowej drutów w linie. Jedynie zastosowanie badań MRT (Magnetic Rope Testing) umożliwia wykrycie całego spektrum uszkodzeń występujących w czasie eksploatacji lin stalowych. Badania NDT lin decydują o bezpieczeństwie pracy i kosztach eksploatacji urządzeń linowych. W artykule opisano warunki eksploatacji lin stalowych na dźwignicach w przemyśle morskim oraz posłużono się przykładem krytycznego uszkodzenia, które wykazuje konieczność priorytetowego zastosowania metody MRT w celu określenia stanu technicznego lin stalowych w czasie ich eksploatacji na dźwignicach.Model matematyczny [L-10] dla metody MFL rozwijany jest w Laboratorium LRMNDE od ponad 40 lat. Aktualny poziom jego zaawansowania pozwala badać wpływ parametrów uszkodzeń i czujników na przebieg i wartość uzyskiwanych impulsów diagnostycznych.

EN

Wire ropes are the weakest parts of rope installations, during their utilization the rope wires are subject to deterioration caused by fatigue of material from repeated bending, surface abrasion, corrosion and mechanical damage. The lifetime of wire ropes is shorter than the lifetime of wire rope installation on which they are installed. The need to remove a wire rope from service is often determined by the most worn section. To date, widely used and standardized destructive tests determining ABL (Actual Breaking Load) as well as VT (Visual Testing) inspection of wire ropes do not give satisfactory results, and with modern multilayer/compact rope designs do not allow to detect fatigue deterioration of wires in the wire rope. Only the use of MRT (Magnetic Rope Testing) testing allows the detection of the entire spectrum of damage occurring during the service life of wire ropes. This article describes the operating conditions of wire ropes on cranes in the offshore industry and uses an example of a critical defects that demonstrates the need to use the MRT method as a priority to determine the technical condition of wire ropes during their utilization on cranes. The mathematical model [L-10] for the MFL method has been developed in the LRM-NDE Laboratory for more than 40 years. Its current level of sophistication allows the influence of defect and sensor parameters on the course and value of the diagnostic indications obtained to be studied.

17

Columnar Dendrite Morphology and Solute Concentration of GH3039 Nickel-Based Superalloys during Wire and Laser Additive Manufacturing: Insights from Phase Field Simulations

Zong Nanfu, Wang Zheng, Liu Yang, Liang Xinghong, Jing Tao

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

387--393

EN

Wire and laser additive manufacturing (WLAM) can produce outstanding mechanical properties of GH3039 nickel-based superalloys. A quantitative rapid phase field model with solute trapping kinetics has been developed during the rapid solidification process, where a range of process conditions are considered in terms of thermal gradients and pulling speeds. Intergranular hot cracking is found to occur at boundaries of tilted columnar dendrite in the GH3039 nickel-based superalloys. The simulations demonstrate that the phase field model considering the interface deflection can represent the dendrite growth during additive manufacturing more realistically. With the aid of numerical simulations, it is determined that dendrite growth morphologies transform from symmetrical columnar dendrite to tilted columnar dendrite as the interface crystallographic deflection is increased, while increasing the deflection angle can lead to uneven composition of material matrix, especially at the columnar dendrite interface. Solute concentrations at the columnar dendrite interface tend to promote hot cracking in additively manufactured Ni-based superalloy.

18

Analysis of Tilted Columnar Dendrites at Grain Boundaries During Wire and Laser Additive Manufacturing: a Phase-Field Study

Zong Nanfu, Sun Weizhao, Liang Xinghong, Jing Tao

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

469--475

EN

Tilted columnar dendritic morphologies are usually existed in wire and laser additive manufactured parts of GH3039 alloy. Overgrowth behaviors induced by the tilted dendritic arrays with a large tilted angle, and the effect of the angle between the growth direction and the direction vertical locally to the solid substrate on primary spacing, solute concentration and morphological evolution have been investigated at both the converging and the diverging grain boundaries through the phase-field simulation. The formation of cracking depends on solidification behaviors including columnar dendrites growth and micro-segregation in the interdendritic region. Furthermore, the effect of the tilted columnar dendrites on the susceptibility of crack is investigated during wire and laser additive manufacturing.

19

Examination of the Force Parameters in Drawing Process of CuZn39Pb3 Cast Rod using Selected Lubricants

Jabłoński Michał

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

99--104

EN

The paper presents the results of research on the wire drawing process of wire brass using different deformation degree and using selected lubricants of different viscosity. The material used for the study was CuZn39Pb3 wire, which was obtained under laboratory horizontal continuous casting process using graphite crystallizer. A cast brass rod with a diameter of 9.4 mm was drawn in laboratory conditions to a diameter of 3 mm and then drawn in one operation to a diameter of 2.9 mm, 2.65 mm or 2.4 mm. Before the final deformation process, the wire surfaces were properly prepared. Based on the results obtained, the drawing tension was used to draw conclusions. The oxide surface has been shown to increase drawing tension and decrease quality of wires, while the surface that has been etched prior to deformation has a beneficial effect both on the reduction of the strength parameters of the drawing process as well as on the improvement of its quality. In addition, it has been shown that despite the emulsion has lowest dynamic viscosity that’s protect wire surface well, decrease the drawing force at high unit loads.

20

Strand wire winding method in a solenoidal coil with limited geometry for good impedance matching

Kilic Veli Tayfun

Archives of Electrical Engineering

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2023

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Vol. 72, nr 1

239--252

EN

This paper reports a new strand wire winding method in a solenoidal coil with limited geometry that enables good impedance matching. In the proposed method strand wires are wound layer-by-layer on top of each other allowing one to set equivalent inductance and resistance of the coil to desired values while obtaining dense magnetic flux and high current carrying capacity. As a proof-of-concept demonstration, simple model setups were constructed with solenoidal coils composed of copper wire strands wound according to the proposed method, and a plastic pipe. The measurements were repeated with a metal shell placed inside the coil to model a complete heating system. System inductance and resistance were measured at two different frequencies. The results show that with the new winding method it is possible to increase a coil’s turn number and the number of strand layers composed by the coil. Also, adding and removing strand layers in the proposed coil architectures enable inductance and resistance values to decrease and increase, respectively, in a controlled way. To understand changes of system parameters, simulations were also performed. The calculated inductance and resistance values in the simulations agree well with the measurement results and magnetic flux distribution created in the system demonstrates the changes.