bluuebunny/crossref_metadata_2025 huggingface dataset:
Reducing Ammonia Consumption and Emissions Using Zeroflow Gas Nitriding
Authors: Małdzinski Leszek , Hemsath Mark K.
Published: April 2024

Gas nitriding has been performed in many ways with many variations over the years (using NH3 only, NH3 + dissociated NH3, and NH3 + N2). Practical heat treating today demands lower costs and gas and energy consumption. With the challenges of ammonia storage, its costs and emissions, the ZeroFlow process reduces ammonia gas consumption and still offers the same capability to affect the nitrided layer, resulting in lower emissions of ammonia and greenhouse gases. Prior analysis has shown that ZeroFlow control allows control of not only the nitriding potential, but also phase composition of the nitrided layer, its thickness and the constituents of the atmosphere used for nitriding. Tremendous experience via actual commercial production has proven that this method of gas nitriding, and the atmosphere used, still allows for precision in controlling growth kinetics of the nitrided layer. The impact on the ammonia consumption and emissions is significant.
Understanding Furnace Atmosphere Composition for Neutral and Gas Carburizing Applications
Authors: Oakes Jim
Published: April 2024

Studying the gas composition of an atmosphere furnace reveals many parameters that can be used to predict metallurgical results of parts being processed. Today’s heat treaters strive for process consistency in order to eliminate variability, rework, and (in the worst case) scrap. In atmosphere heat treating, understanding control parameters and atmosphere composition provides critical insight into expected results. In this presentation, the audience will have the opportunity to observe gas compositions that would typically be found in carbon-neutral or carbon-rich atmospheres; they will also be able to see how atmospheric properties directly affect the metallurgical properties of heat treated parts. The presenter will illustrate examples of common atmospheres based on furnace types and will discuss common characteristics of improperly controlled atmospheres and how those atmospheres can lead to flawed results. Real-world examples of metallurgical results will be used to illustrate what can be expected from an “out of control” situation.
Understanding Process Sensitivities in Press Quenching— An Integrated Approach
Authors: Reardon Arthur C. , Freborg Andrew , Li Z. Charlie , Ferguson B. Lynn
Published: April 2024

Press quenching is a specialized quenching technique used in heat treating operations to minimize the distortion of complex components such as spiral bevel gears and high quality bearing races. The quenching machine is designed to control the geometrical characteristics of components such as out-of-round, flatness, and (if the tooling is designed to accommodate it) taper. The achievement of final dimensional tolerances is accomplished through a trial and error process where the incoming machined sizes of the components are adjusted based upon measurement data taken from the initial sets of quenched and tempered components that have already been processed through the press quenching operation. Oil flow rates can be altered during the different stages of the quenching cycle, and through the use of specialized tooling the oil flow pathways can be selectively adjusted to meter the oil flow towards specific areas of the part surface while baffling it away from others in order to provide a more uniform overall quench. Complex metallurgical changes take place during austenitizing and quenching, resulting in corresponding mechanical property changes. Accompanying these changes are the generation of thermal and transformation induced stresses, which produce in-process and final residual stresses. During press quenching, dimensional restrictions add additional complexity to the combined effects of thermal and mechanical process sensitivities on these stresses. And if the stresses are severe enough, quench cracking can result. In this investigation the quench cracking of an asymmetrical AISI 52100 bearing ring is evaluated through physical experiments and through corresponding heat treatment process modeling using DANTE. The effects of quench rate, die load pulsing, and several other process variables are examined experimentally and/or analytically to illustrate how they can impact the resulting stresses generated during the press quenching operation.
Effects of Polymer Concentration in Quenchant Bath
Authors: Schlitzer Justin , Hollenbeck John
Published: April 2024

The properties of heat treatable wrought aluminum alloys are primarily achieved through use of solution heat treatment processes defined in AMS 2770. Variation in these processes can greatly influence the final properties of the aluminum alloy material. This study specifically investigates the effects of the quenching solution used during the wrought aluminum alloy heat treatment process. The research varies the Type 1 polymer concentrations between 10 and 25 percent in the quenchant solution. The scope is limited to investigate aluminum 6061 and 7075 alloys treated to the T6 condition and uses plate stock ranging 1 to 2.5 inches in thickness. Statistical analysis is used to determine the magnitude of the effect of polymer percentage on material properties of the aluminum alloys at these conditions. This research is conducted to determine the basis for the glycol restrictions within the ranges typical to internal manufacturing processes. The conclusions of this research are based on statistical evaluation of tensile, yield, hardness, grain size and electrical conductivity results obtained as a result of the investigation.
Prediction of Mechanical Properties and Microstructure Composition of Quenched and Tempered Steel
Authors: Smoljan Božo , Iljkić Dario , Tomaši Neven
Published: April 2024

The mathematical model and computer simulation for the prediction of mechanical properties in quenched and tempered steel specimen was developed. In addition, mathematical model for prediction of microstructure composition of quenched and tempered steel was developed. In calculation of both, mechanical properties and microstructure composition the history of cooling was taken in account. Hardness of quenched and tempered steel was expressed as function of maximal hardness of actual steel and representatives of chemical diffusivity. After that, distribution of other relevant mechanical properties can be obtained. The mathematical model is developed for carbon and low alloyed steel. The studied model is based on Jominy test results. The established procedure was applied in computer simulation of quenched and tempered steel workpiece.
Rockwell Hardness Bench Testing of Induction Heat Treated Work Pieces
Authors: Specht F. R.
Published: April 2024

Hardness bench testing is a simple and universally accepted practice for checking induction hardened parts and is performed in literally thousands of manufacturing facilities. There are trained metallurgical professionals who have spent years studying and training in this art. However these days many new users are given only the basics during a quick show and tell: this paper is intended for these up and coming heat treaters or quality engineers. The presentation will reveal simple to understand rules for proper work piece cutting, surface preparation, and other factors in the preparation of induction hardened samples for bench hardness testing. Selection of the best RC scale to use based on the part configuration and size will be reviewed.
Controlled Gas Nitriding/Nitrocarburizing Process Control and Precalculation Possibilities
Authors: Heineck S. , Theisen Frank
Published: April 2024

To achieve optimal component properties through controlled gas nitriding, a precise approach is required. This method utilizes nitride layers with a defined structure, tailored to the specific stresses each component will encounter. Success relies on three key factors: firstly, understanding the ideal layer structure for a given stress profile, which informs the desired properties of the surface layer. Secondly, in-depth knowledge of material behavior during nitriding, considering both the material itself and the nitriding conditions, is crucial for material selection and parameter optimization. Finally, achieving consistent and predictable results hinges on the precise measurement and control of nitriding conditions, particularly the nitriding potential.
How It’s Done and Why— Transitioning Parts from Atmosphere Carburizing to Low-Pressure Vacuum Carburizing
Authors: Lelong Vincent , Welch Amberlee
Published: April 2024

For more than 20 years now Low Pressure Vacuum Carburizing (LPC) has taken over several industries as the main carburizing choice. These industries take advantage of LPC’s clean environment, versatility, “just in time” processing, along with possible distortion control that comes with gas quenching capabilities to process millions of parts each month. However, there are still hundreds of types of parts that can be converted to LPC with minimal effort. The authors will show the recent history and products currently being processed in LPC and how they were transitioned to LPC. Metallurgical results will be shown along with production loading scenarios. In addition, the process of a particular part showing timing and cost of each treatment process will be reviewed. These facts will show the audience the benefits and how they can take advantage of low pressure vacuum carburizing.
Plasma Nitriding Potential and a New Modeling Approach for Plasma Nitriding Process Control
Authors: Skalecki Marian Georg , Klümper-Westkamp Heinrich , Hoffmann Franz , Zoch Hans-Werner , Bischoff Sebastian , Rohde Jörn
Published: April 2024

Plasma nitriding is a thermochemical surface heat treatment of steel components to produce nitride layers which increase wear-, corrosion- and fatigue resistance. Research into plasma nitriding lately showed that there is a significant and characteristic amount of ammonia formed off the process gases nitrogen and hydrogen. This research paper is aimed to analyze the influence of plasma treatment parameters, such as pressure, voltage, temperature and nitrogen to hydrogen ratio on the atmosphere and the formation of ammonia during plasma nitriding. The ammonia content is measured in the exhaust gas. By correlating the measured ammonia with the treatment parameters and modeling the nitriding process, the ammonia content can then be predicted. Further a plasma nitriding potential, comparable to the gas nitriding potential, based on ammonia content is calculated and its practicability as process control parameter is shown by correlating the potential with the nitriding results, e.g. the formation of ε and γ’ nitride phases.
Effect of Heat Treatment on the Microstructure, Mechanical Properties, and Corrosion Behavior of Ti-6Al-4V via Direct Metal Laser Sintering
Authors: Xu Yangzi , Lu Yuan , Sisson R.D.
Published: April 2024

This paper presents the results of an experimental investigation of the effect of three types of post-heat treatments: 1) solution treatment and aging, 2) stress relieving, and 3) annealing on the corrosion behavior of Ti-6Al-4V fabricated via direct metal laser sintering (DMLS). The microstructure and phase evolution as affected by heat treatment temperature were examined through scanning electron microscopy and via x-ray diffraction. The Vicker’s microhardness, as it was affected by various heat treatments, was compared. The corrosion behavior of the specimens was measured electrochemically in simulated body fluid at 37°C. It was found that the nonequilibrium α’ phase with a small amount of β nuclei was formed in the as-fabricated sample. Heat treatments allow the formation of the β phase and the agglomeration of β precipitates to occur at elevated temperatures. Transformed β phase with various morphologies was observed as a result of the heat treatments. Different degrees of improvement in the corrosion resistance were observed in the solution-treated and aged samples, 650 °C stress relieved, and annealed samples.
Meandering Winding Magnetometers for the Evaluation of Surface Hardness on Carburized Steel
Authors: Zhang Lei , Sisson Richard D.
Published: April 2024

As part of a project to identify nondestructive techniques to determine the surface hardness and case depth of carburized steel, Meandering Winding Magnetometers (MWM) measurements were evaluated. MWM technology is based on eddy current testing. Compared to traditional eddy current testing, MWM measurements integrate the generating coil and detection coil into a thin, flexible sensor that can be applied to complex geometries. Conductivity and permeability are measured with MWM equipment to evaluate the properties of carburized steel. For this study, samples of 8620 were carburized to selected hardness and case depths. MWM technology was determined to be an effective method to detect surface hardness. The results of this study are presented and discussed in this paper.
The Influence of Temperature on the Austenite Grain Size and Microstructure of 4140 Steel
Authors: Zhang Rui , Sisson Richard D.
Published: April 2024

Grain growth during heat treatment can affect mechanical properties. A large grain size can result in a lower strength and susceptibility to brittle failure. In order to control the prior austenite grain size, the effect of Austenitizing temperatures and holding times on the grain size and hardness in 4140 steel was experimentally investigated. Samples were heat treated at 900, 1000, and 1100 °C, and held for 1, 4, and 9 hours. After austenitizing, samples were cooled in the furnace to 850 °C before they were quenched in water at room temperature. Each sample was cut, mounted, and polished. Rockwell hardness and microhardness tests were performed on each sample. A Picric etch was used for grain size analysis. The grain size was measured following the E112 standard test method. It was found that the prior austenite grain size increased with temperature and time according to the standard grain growth model. It was also found that the as-quenched hardness decreased with an increase in grain size.
Induction Coupled Thermo-Magnetic-Processing (ITMP)
Authors: Ahmad Aquil , Pfaffmann George
Published: April 2024

This paper describes a study to address sustainability by improving the power density of induction-coupled thermo-magnetic processing treatment of low-cost steel alloys. Application of a 9Tesla magnetic field in heat-treating improved the performance of the low-cost steels to rival that of exotic, costly alloys in properties and performance.
How Mass Imbalance and Cold-Sink Effects Influence Induction Hardened Case Depth
Authors: Bernhard Andrew
Published: April 2024

Induction heating is very sensitive to part geometry. How mass is distributed in a part can have a strong influence on how it heats and the case depth that can be achieved. One application where this has been observed is in the internal hardening of connecting rod journals. These parts have an uneven distribution of mass that causes a cold-sink effect due to the position of the rod on one side of the bore. Computer simulations of the heating and cooling processes show how the mass imbalance affects the temperature in different areas of the workpiece, and they yield insights into how the temperature history of the different areas influences the resultant microstructure after hardening. The phenomena observed may be applicable to any part having a feature to be hardened with uneven mass distribution around the feature, and principles discussed herein can aid in design of such parts for induction heat treating.
Advanced Robotics in Heat Treat Verification Using Eddy Current
Authors: DeVries Dan
Published: April 2024

Eddy current is a non-destructive testing technique proven for use in heat treat and material structure verification. Modern multi-frequency eddy current instruments can test for conditions such as misplaced case, shallow case, short heat, short quench, and delayed quench. Eddy current testing offers many benefits over traditional heat treat validation methods. Unlike sample testing processes using cut, polish, etch, and visual inspection techniques, eddy current testing provides a clean, fast, and repeatable process that can perform in-line inspections of all parts produced. Eddy current inspections have traditionally focused on symmetrical parts such as wheel bearings and gears. However, advances in robotics have paved the way for cost-effective inspection of non-symmetrical, complex components that would have previously required multiple test stations. Robotics also provides a low-cost way to retest, null, and periodically proof the testing process using multiple conditions of masters. This has been difficult and expensive with other types of automation and operator involvement.
Torsional Fatigue Behavior of 8620 Steel Subjected to High-Magnetic Field Thermal Processing
Authors: Larsen James M. , Govier Erin M. , Glass Matthew J.
Published: April 2024

The potential for improving mechanical properties of steels via thermal processing (e.g. austenization and rapid quenching) through modified phase equilibria in the presence of a high magnetic field has been the subject of numerous recent works [1,2]. In this study, torsional fatigue performance of case-carburized SAE 8620 re-austenitized and quenched inside of a 9 Tesla, 5” diameter superconducting magnet is reviewed. Conventional atmosphere furnace carburized hardened and tempered, and in-situ magnetic field re-hardened and tempered material (Induction Thermo-Magnetic Processing, or “ITMP”) was subjected to fully-reversed torsional loading. Both Special Bar Quality (SBQ) bar and forged SBQ bar steel in carburized conditions were heat treated and mechanically tested. There was no measurable difference in fatigue behavior for either condition when comparing conventionally heat-treated and ITMP re-hardened populations.
Austempering: Process, Applications, and Equipment
Authors: Titus Wallace John , Neumann Michael E.
Published: April 2024

Austempering is an alternative hardening process that has been operating under the radar of manufacturers and designers for decades, primarily because its application is directed to fasteners having a cross-section of 12.7 mm or less. The primary goal of austempering is to create an extremely tough microstructure throughout the part’s mass or cross-section, a typical requirement for fasteners. This paper provides an overview of austempering processes and applications.
Simulation of Nitriding Processes
Authors: Winter Karl-Michael
Published: April 2024

This paper presents a new approach for predicting nitriding and nitrocarburizing results. The model calculates thermodynamic and kinetic effects based on material composition and pre-nitrided conditions. It can simulate up to three-stage recipes with varying temperatures, nitriding potentials, and carburizing potentials while also taking nucleation time into account. The simulation result gives compound layer thickness, precipitation layer, and total diffusion depth and calculates surface hardness, core hardness, and effective case depth.
Application of Vegetable-Based Quench Oil to Achieve Safety and Environmental Advantages
Authors: Nebbe Jonn , MacKenzie D. Scott
Published: April 2024

An induction hardening operation heat treating engine valves previously used a typical medium speed quenching oil for the quenchant. A change-over to vegetable-based oil was accomplished, with the goal of reducing fire hazards; reducing smoke and fumes; and providing a cleaner working environment. All the desired goals were achieved, with additional advantages of no changes in microstructure, and improved part distortion. This paper compares the physical properties of the two oils, and documents improvements in working environment.
Defining the Adequacy of Direct Harden Water Quench Systems
Authors: Pershing Michael A. , Barnes Christopher A. , Birky Zachary S.
Published: April 2024

Developing heat treat systems and control plans that produce consistent direct harden (quench and temper) results with a high percent martensite and the corresponding proper mechanical properties is challenging for large components or large batch sizes. In this study, large section bars in alloys suitable for water quenching were austenitized and quenched under controlled flow conditions. The bars were primarily examined by several as-quenched hardness versus depth traverses in order to be sure localized non-martensitic regions (soft areas) would be detected. The tests allowed for some key insights into defining the adequacy of direct harden water quench systems, including the idea of agitation thresholds required for each alloy grade or hardenability level to prevent soft spots (spotty hardening) on large section steel components.
Metallurgical Behavior of SAE 1045 Steel Quenched into Chemically Modified Bioquenchants
Authors: Simencio Otero Rosa L. , Canale Lauralice C.F. , Totten George E.
Published: April 2024

It is well known that petroleum oil base stocks possess a number of limitations, such as being non-renewable, but even more importantly, they are considered relatively toxic with limited biodegradability. One class of base stock that is renewable with excellent biodegradability characteristics and that is generally, but not always, non-toxic is animal and seed oils. The quenching performance of many different animal and vegetable oil compositions has been reported in the literature. However, as a class, they suffer from generally poor thermal oxidative stability, even when containing oxidation inhibitors, when compared to quenchants derived from petroleum oil. This factor limits their potential commercial utility. One method of addressing this problem is to chemically modify the vegetable oil to produce increased resistance to thermal-oxidative degradation. This work discusses the physical properties and quenching performance of epoxidized soybean oil-based formulations and the resulting metallurgical properties, hardness, and microstructures obtained. These results have not been reported previously.
Predictive Model of Wire Rod Cooling
Authors: Viéitez Iván , López-Cancelos Rubén , Martín Elena B. , Varas Fernando
Published: April 2024

Wire rod of steel, produced by a hot rolling process, is cooled on a conveyor by action of fans sited under it. Mechanical properties of rod depend on chemical composition of steel and cooling rate experimented by the product. A mathematical model is developed in order to predict the thermal and metallurgical evolution of the steel rod on the conveyor. Convection and radiation losses are considered and the influence of the laying head is also discussed. Simulation results are compared with experimental measures obtained by an optical pyrometer in a real industrial process. Several product diameters and fan configurations are analyzed. Conclusions about the good accuracy of the model are shown. Thanks to the short computational time that the developed tool takes to predict the temperature of the wire rod along the conveyor, the tool can be potentially used in an on-line control system for the cooling process of wire rods.
Effect of Hardenability on Temperature and Phases of Spiral Bevel Gear in Press Quenching Process
Authors: Wang Gang , Zhang Yingtao , Yang Lin , Cui Lei , Li Zhichao (Charlie)
Published: April 2024

Press quenching is an effective method to improve the strength and control the distortion of auto gears. However, it can be challenging to understand, predict, and further minimize the deformation of circular-arc bevel gears in industrial applications because of multiple influencing factors. This paper reports on work to build a comprehensive model with phase changes to reproduce the gear quenching process with consideration of the quenching machine, process parameters, and variation of steel compositions. The phase content and temperature history predicted by the model agree with the gear-quenching experimental results.
Implementation of a Boiling Heat Transfer Model Based on an Experimental Database
Authors: Banka Andrew L. , Franklin Jeffrey D.
Published: April 2024

Extensive steady-state flow boiling heat transfer data have been collected for both water and oil using a test rig that allows for control of the primary variables of fluid velocity, fluid temperature, surface temperature, and surface orientation. Using the resulting database, functional relationships for boiling heat transfer trends have been determined. These boiling heat transfer relationships have been incorporated into the Ansys-Fluent commercial CFD package using a user-defined function (UDF). This software combination provides a simulation tool capable of approximating the quenching of metal parts by applying a situationally correct heat flux at each point in the part surface throughout the quench cycle. No manipulation of model tuning parameters is required. Simulation predictions are compared to test data collected for a cylindrical forging.
Enhanced Heat Transfer Coefficient Method to Model Air Quench Process— Investigation of Heat Transfer Coefficient Characteristics by CFD Methods
Authors: Jan James , Prabhu Eben , Chen Xingfu , Weiss Ulrich
Published: April 2024

Air quenching is a common manufacturing process to produce high strength metal component by rapidly cooling heated parts in a short period of time. With the advancement of finite element analysis (FEA) methods, it has been possible to predict thermal residual stress by computer simulation. However, the accuracy of FEA calculation is bounded by the accuracy of the temperature data, acquired either by thermocouple measurement, experimentally calibrated heat transfer coefficient (HTC) method, or computational fluid dynamics (CFD) calculation. While CFD methods have gained popularity, the practicality of CFD method is reduced by tedious mesh generation and costly computation that is only feasible to be performed on a supercomputer. When quenching media is a gas-phased fluid and quenching flow is steady, the flow and temperature fields exhibit certain characteristics that could lead to the development of enhanced HTC method that is more computation efficient and yet produces more accurate temperature data.
Ring Gear Microstructure and Heat Treat Response
Authors: Lee Ying-Liang R. , Rowan Olga K. , Pershing Michael A.
Published: April 2024

Ring gear distortion from heat treatment processes has been a challenge to gear manufacturers. To provide good post heat treatment dimensions, efforts have been made to optimize post heat treat controls such as quench apparatus, quench severity and post heat treatment grinding. However, the impact of prior-to-heat treatment gear microstructure is not fully understood. In this study, ring gears with different prior-to-heat treatment (initial) microstructures were compared against post-heat treatment dimensional measurements. Statistical analyses were performed on data collected over 2 years at a production facility. Heat treat growth was found to be strongly affected by the initial microstructures and green hardness. Recommendations were made to help reduce heat treat growth variation.
Direct Forge Quenching of Medium Carbon and Low-Alloy Steel Forgings
Authors: Bajaj Priyanshu , Pathak Udayan B.
Published: April 2024

The effect of forging temperature and temperature before quenching on microstructure is studied. This is related to the mechanical properties like tensile strength, yield strength and impact toughness. It was observed that martensitic needles in direct quenched parts were slightly longer than the normal hardened and tempered parts. This was attributed to the coarser prior austenite grain size, resulting in fewer nucleation sites in case of direct quenched parts.
Modeling of Composition and Stress Profiles in Low-Temperature Surface Engineered Stainless Steel
Authors: Jespersen Freja N. , Hattel Jesper H. , Somers Marcel A.J.
Published: April 2024

Thermochemical surface engineering by nitriding/carburizing of stainless steel causes a surface zone of expanded austenite, which improves the wear resistance of the stainless steel while preserving the stainless behavior. As a consequence of the thermochemical surface engineering, huge residual stresses are introduced in the developing case, arising from the volume expansion that accompanies the dissolution of high interstitial contents in expanded austenite. Modelling of the composition and stress profiles developing during low temperature surface engineering from the processing parameters temperature, time and gas composition is a prerequisite for targeted process optimization. A realistic model to simulate the developing case has to take the following influences on composition and stress into account: - a concentration dependent diffusion coefficient - trapping of nitrogen by chromium atoms - the effect of residual stress on diffusive flux - the effect of residual stress on solubility of interstitials - plastic accommodation of residual stress. The effect of all these contributions on composition and stress profiles will be addressed.
Influence of Plastic Deformation on Low-Temperature Surface Hardening of Stainless Steel by Gaseous Nitriding
Authors: Bottoli Federico , Winther Grethe , Christiansen Thomas L. , Somers Marcel A.J.
Published: April 2024

This article addresses an investigation of the influence of plastic deformation on low-temperature surface hardening by gaseous nitriding of three commercial austenitic stainless steels: AISI 304, EN 1.4369 and Sandvik Nanoflex with various degrees of austenite stability. The materials were plastically deformed to different equivalent strains by uniaxial tension. Gaseous nitriding of the strained material was performed in ammonia at atmospheric pressure in the temperature range 693-703 K (420-430°C). Microstructural characterization of the as-deformed states and the nitrided case included X-ray diffraction analysis, reflected light microscopy and microhardness indentation. The results demonstrate that a case of expanded austenite develops and that, in particular, the presence of strain-induced martensite in the initial (deformed) microstructure has a large influence on the nitrided zone.
New Applications for Synchronized Vacuum Heat Treatment
Authors: Heuer Volker , Löser Klaus , Gornicki Bill
Published: April 2024

A recently introduced new vacuum furnace design allows the total integration of heat treatment into the manufacturing line. This compact unit can be implemented into the heart of the production chain and provides heat-treatment processes which can be fully synchronized with the green and hard machining-operations. When performing case hardening, the components are low pressure carburized at high temperatures (1050°C) followed by gas quenching. Using this technology, the components are treated in most cases in a single layer of parts (“2D-treatment”) which allows for an easy automated loading and unloading of the fixture-trays. Furthermore this “small batch – treatment” leads to an optimum in quality regarding quench homogeneity and distortion control. By using the small batch concept, a continuous flow of parts can be established. There is no need to wait until enough parts are collected to build a large batch with multiple layers (“3D-batch”). Therefore excessive costs are avoided for inventory, part storage and transportation within the plant. Typical components for this technology come from the automotive, aerospace and tool industry. The paper shows several new results from case hardening applications.
Comparative Impact Behavior of High C Steel after Conventional Quenching and Tempering and Austempering
Authors: Vatavuk Jan , Totten George E. , Nucci José E. , Albano Luigi L.M. , de C.F. Canale Lauralice
Published: April 2024

Usually bainitic microstructures exhibit good toughness and austempering is typically the preferred heat treatment when toughness is the primary requirement of the component. Several reports have shown such characteristics when compared to tempered martensite. High carbon steel may exhibit brittle characteristics but it is a good steel with respect to mechanical properties and wear resistance. The objective of this study was to compare the impact properties of AISI O1, a high carbon tool steel as VND in Brazil. This was done by comparing Charpy impact strength under different heat treatment cycles. Tempered martensite and bainite was obtained at 350°C after holding at temperature for 20, 40, and 60 minutes. Since hardness influences impact behavior, comparative studies were performed at the same surface hardness level. Results show a low absorbed energy for the austempered samples which for this temperature is independent of the holding time.
Wear Properties of a Gray Cast Iron Coated with Niobium Carbide Produced by Pack Process
Authors: Mariani Fábio Edson , de Assis Gustavo Bortoluci , Casteletti Luiz Carlos , Neto Amadeu Lombardi , Totten George Edward
Published: April 2024

Gray cast iron is primarily used for its low cost, high damping capacity, and excellent machinability. These properties are attributed to the presence of free graphite and the high fluidity of the molten metal, which allows for the easy casting of complex parts with thin walls. Applying suitable coatings can enhance wear resistance and broaden the material's range of applications. Niobium carbide, known for its high hardness, is a promising candidate for this purpose. In this study, samples of gray cast iron with the composition 3.47% C, 2.39% Si, 0.55% Mn, 0.15% Ni, 0.65% Cu, and the balance Fe were subjected to a niobizing powder thermo-reactive diffusion treatment. The coating mixture consisted of ferro-niobium, NH4Cl, and Al2O3, and the treatment was conducted at 900 °C for 2 hours. The resulting layers exhibited hardness values of 2000 HV, characteristic of niobium carbides. Micro-adhesive and micro-abrasive wear tests showed a significant increase in wear resistance due to this treatment.
Heat Treatment of Precipitation-Hardening Stainless Steels Alloyed with Niobium
Authors: Casteletti Luiz Carlos , Mariani Fábio Edson , Neto Amadeu Lombardi , Filho André Itman , Totten George Edward
Published: April 2024

Precipitation-hardening stainless steels are iron-nickel chromium alloys containing precipitation hardening elements such as aluminum, titanium, niobium and copper. In this work, heat treatment of a novel precipitation hardening stainless steel using niobium as a forming element for the hardening precipitates in order to increase its surface hardness and wear resistance was performed. The steel composition was 0.03C - 0.22Si - 17.86Cr - 3.91Ni - 2.19Mo - 1.96Nb (in wt%). The samples were solubilized at 1100 °C for 2 hours. Cooling was done in oil and the samples were subsequently aged at 500, 550 and 600 °C. The solubilized samples exhibited an average hardness of 30 HRc and after the aging treatments, the hardness increased to 46 HRc. The hardness increases during the aging treatments were very fast. A 5 minute treatment achieved hardness levels that were close to the maximum obtained for this alloy. Niobium was an efficient precipitation hardeners forming a Laves phase of the type Fe2Nb.
Guía de aplicación de técnicas de fitomanejo para la restauración ambiental de depósitos de residuos mineros metalíferos en zonas semiáridas
Authors: Álvarez Rogel José , Martínez Sánchez Juan José , Conesa Alcaraz Héctor Miguel , Franco Leemhuis José Antonio , Ceacero Moreno Matías
Published: April 2024

Los depósitos abandonados de residuos mineros consistentes en lodos de flotación procedentes de lavaderos de mineral suponen un problema medioambiental debido, sobre todo, a las concentraciones extremadamente altas de metales (por ejemplo, Zn, Pb, Mn) y metaloides (por ejemplo As) que contienen. A causa de la gran cantidad de depósitos abandonados que existen, es poco viable asumir los gastos y las dificultades técnicas de restaurar todos ellos por métodos como su retirada y transporte a vertedero o su encapsulado. Estas actuaciones deberían priorizarse cuando los depósitos entrañen un riesgo inaceptable por colapso y/o por su cercanía a poblaciones. El fitomanejo puede complementar otras opciones más costosas, ayudando a reducir el riesgo de que los depósitos sean una fuente de dispersión de elementos potencialmente peligrosos, al mejorar sus suelos, facilitar el crecimiento de plantas directamente sobre ellos y mejorar el ecosistema.
Levantamento do uso terapêutico do canabidiol por veterinários na região metropolitana de Belém do Pará
Authors: Costa Agada Thiare , Silva Aryane , Tavares Helamã , Machado Luan , Pereira Rychel
Published: April 2024

The present study aimed to analyze the knowledge of veterinarians in the metropolitan region of Belém do Pará regarding the use of Cannabis sativa for medicinal purposes in veterinary medicine. To this end, structured questionnaires were applied through the google forms platform. The data obtained were presented in percentages in order to collect information on this subject, which is of fundamental importance for the creation of dissemination strategies regarding the medicinal use of Cannabis. More than 40% of respondents claim to have gained knowledge on the matter through scientific articles and understand the importance of its integration into the clinical routine, and more than 90% believe that research on the use of medicinal Cannabis needs to be stimulated and have greater dissemination. The affirmation of the need for more studies on the use of cannabidiol in small animals is clear in the common opinion of the interviewees, including the need to utilize tools such as social media to bring this knowledge to people who can be both professionals in the area, as well as tutors who are interested in the subject.
Інтерпретація «хутірської філософії» в романі Люко Дашвар «РАЙ.центр»
Authors: Плющик Оксана
Published: April 2024

At the beginning of the 21st century, a specific category of the artistic model of «peasantry», which is rooted in a peculiarly Ukrainian «philosophy of the heart» (cordocentrism), gets a new life and moves away from religious interpretation, turning towards national, spiritual, anthropological components. In the metaphilosophical sense and interpretation, Ukrainian cordocentrism is a national philosophy, which in artistic images and theoretical concepts expresses the awareness of human integrity and the understanding of the inseparable unity of man with God, spiritual reality, the transcendent. The study of changes and features of the transformation of this worldview in the work of domestic writers, in particular, Liuko Dashvar, would contribute to the continuity of artistic models traditional for Ukrainian literature. Therefore, there is a need for a thorough study of the features of the artistic interpretation of «khutir’s philosophy» as a specific worldview system in modern Ukrainian literature with taking into account its genre and style trends. Thus, in our study, through the prism of «khutir’s philosophy», an analysis of modern youth and the urban rich was carried out with emphasis on two spaces — the city and the small town. The system of characters is built according to two lines: images from the first,«people from the people» (carriers of true spiritual values), opposed to the immoral world of the city, in particular, those in power (the embodiment of social vices). Accordingly, the space of a district center, a town, a village is opposed to a metropolis as a center of decency and humanity to a space of greed and moral degradation. In the novel, the main worldview modes of the «khutir’s philosophy» are correlated with the system of character images and the organization of the artistic space. It was concluded that in Ukrainian literature, the «khutir’s philosophy» retains its significance as a holistic worldview which is manifested in the problematic of the works, the author’s principles of organization of the characters’ system and the chronotope.
Doprinos Maše Janković razvoju modne ilustracije u Hrvatskoj početkom 20. stoljeća
Authors: Simončić Katarina Nina
Published: April 2024

Maša (Marija) Janković (Ždala, 7. rujna 1878.–?), slikarica, učiteljica, modna ilustratorica i urednica Modnog priloga u časopisu Domaće ognjište (1907./1908.), svoje obrazovanje započinje u Zagrebu. Godine 1897. završava Žensku učiteljsku školu sestara milosrdnica, a potom odlazi u Beč, München i Prag, gdje izučava slikarstvo. Po povratku u Zagreb, 1906. postaje učiteljica u Zemaljskoj višoj djevojačkoj školi u Zagrebu. Usporedno se bavi slikarstvom, izrađuje modne ilustracije i nacrte hrvatskih tradicijskih ornamenata za njemačke i bečke modne žurnale. U razdoblju uređivanja Modnog priloga od 1907. do 1908. svojim radom pridonosi promociji modnih trendova s obilježjima nacionalnog izraza i vrednovanju struke modnog ilustratora. Istraživanjem njezina uredničkog djelovanja razmotrit će se načini prezentacije modnih fenomena i bilježenja elemenata tradicijske baštine te likovni karakter modnih ilustracija prve do sada poznate potpisane hrvatske autorice.
ФАКТОРНИЙ АНАЛІЗ ДИНАМІКИ АЗОТНИХ РЕЧОВИН ВОДИ РІЧКИ СТИР У ЗОНІ ВПЛИВУ РІВНЕНСЬКОЇ АЕС
Authors: Бєдункова О. О. , Кузнєцов П. М.
Published: April 2024

Актуальним питанням впливу атомної енергетики на довкілля є надходження зворотної охолоджуючої води до поверхневих вод водойм-водоприймачів, які містять залишкову кількість теплової енергії. У поєднанні з цілим комплексом природних факторів це може спричинити негативні зміни водно-екологічних процесів, зокрема порушення балансу речовин азотної групи. Метою статті було проведення факторного аналізу динаміки азотних речовин води р. Стир у зоні впливу Рівненської АЕС для оцінки прояву екологічного ефекту від скидів відпрацьованих зворотних вод із залишковою тепловою енергією. Ряди даних спостережень складали результати щомісячного контролю азоту амонійного (NH4+), нітритів (NO2¯) та нітратів (NO3¯) на ділянках р. Стир до та після скиду промислово-зливової каналізації РАЕС, впродовж 2018–2021 рр. Виявлено, що середні значення вмісту в воді р. Стир речовин азотної групи незначно відрізняються на досліджуваних ділянках. Відмічено тенденцією підвищення концентрацій азоту амонійного (NH4+) у холодний період року та нітритів (NO2¯) у теплий період року. Встановлено статистично значимий обернений регресійний зв’язок між концентраціями у воді азоту амонійного та нітратів (r=-0,51 та r=-0,47 відповідно) і відсутність зв’язку між азотом амонійним та нітритами та високий кореляційний зв’язок за вмістом азоту амонійного (NH4+) – 0,867, нітратів (NО3-) – 0,825  та нітритів (NО2-) – 0,897 на окремих ділянках. Оцінено факторне навантаження на концентрацій речовин. Відмічено збалансованість природного процесу відновлення та окиснення азоту в циклі його перетворення у водному середовищі досліджуваних ділянок р. Стир. Зроблено висновок про відсутність негативного впливу стоків ПЛК Рівненської АЕС на баланс азотних речовин. Стверджується про відсутність прояву водно-екологічних реакцій р. Стир на тепловиділення РАЕС.
ОБҐРУНТУВАННЯ КОНЦЕПЦІЇ СТАЛОГО РОЗВИТКУ ГОРОДОЦЬКОЇ СІЛЬСЬКОЇ РАДИ
Authors: Клименко M. O. , Янковська А. Ю.
Published: April 2024

У статті проаналізовано недоліки розроблених вперше та введених в дію «Стратегій сталого розвитку об’єднаних громад або сільських рад», які полягають у відсутності в них об’єднуючих ідей для згуртування населення та здійснення конкретних кроків, спрямованих на встановлення балансу між задоволенням сучасних потреб населення і захистом інтересів наступних поколінь, включаючи їх потреби в екологічно безпечному довкіллі. Зазначається, що концепція включає соціальну, економічну, екологічну складові і розробляється з врахуванням конкретних принципів: надання розвитку довготривалого характеру, націлення на задоволення потреб населення, узгодження потреб населення з можливостями територій, збереження та збалансоване використання природно-ресурсного потенціалу. Наводяться стратегічні пріоритети розвитку сіл, а саме: виробництво інноваційної промислової продукції, екологічної продукції для споживання населенням, покращення інфраструктури сіл, охорона життя і оздоровлення населення, збереження довкілля.

Аналізуються проблеми і перешкоди, які існують у сільській раді: низький рівень знань населення щодо процесів сталого розвитку, нераціональне використання природно-ресурсного потенціалу, низької активності населення і представників бізнесу у впровадженні ідей сталого розвитку і прогресивних змін: у соціо-економіко-екологічному стані сільської ради.

Пропонується об’єднуюча ідея для сільської ради, суть якої полягає у створенні на її території екологічно безпечних поселень і переведення їхнього розвитку на ближню і віддалену перспективу на сталий розвиток. Наголошується, що головним завданням екологічно безпечних поселень на початковому етапі є стимулювання розвитку сільської ради, націлений на створення малих і середніх підприємств, які виходять на ринок з новою технологією або новими продуктами з доданою вартістю, покращення добробуту населення і збереження довкілля.

Для обговорення пропонується сформульоване визначення стратегічного бачення та стратегічна місія Городоцької сільської ради.
ЕКОЛОГІЧНІ АСПЕКТИ РОЗВИТКУ БІОЛОГІЧНОЇ СИСТЕМИ ЗЕМЛЕРОБСТВА В УМОВАХ ГЛОБАЛЬНИХ ЗМІН КЛІМАТУ
Authors: Скок С. В.
Published: April 2024

Інтенсифікація сільського господарства в умовах глобальних кліматичних змін призвела до деградації ґрунтів, порушення екологічної рівноваги в агроекосистемах та проблем безпечного харчування людини. Пріоритетним завданням сучасного землеробства є збільшення виробництва високоякісної продукції рослинництва із застосуванням біологічних технологій вирощування  сільськогосподарських культур. Незважаючи на глобальну світову тенденцію збільшення частки застосування біологічних методів до 10%, використання біологічних препаратів в Україні є мінімальним (4%). З урахуванням несприятливих агрокліматичних умов на півдні України, які проявляються високою середньорічною температурою повітря та недостатньою кількістю опадів, перехід на новітні технології ведення сільського виробництва із застосуванням біологічних препаратів зумовить збільшення продуктивності сільськогосподарської продукції у посушливих умовах та зниження пестицидного навантаження на ґрунти. Широке впровадження біологічних препаратів у сільськогосподарське виробництво залежить від якісних показників ґрунту. Встановлено, що найвища стимулююча дія біологічних засобів захисту рослин спостерігається за високих показників природної родючості ґрунтів, вмісту органічних та поживних речовин. Протягом останніх 100 років  вміст гумусу в ґрунтах на території України знизився від 6% до 3,2% внаслідок глобальних кліматичних змін, ерозійних процесів, недотримання сівозмін, використання застарілих методів обробки сільськогосподарських земель, хімічних засобів захисту рослин та мінеральних добрив. В умовах дефіциту гумусу порушується функціонування ризосферної мікробіоти, синтез мікроорганізмами біологічно активних сполук, засвоєння поживних речовин рослинами. Встановлено, що основна частина мікробоценозу міститься у верхньому шарі 5–15 см у кількості 3 тонн мікробної маси, яка найбільше піддається впливу ерозійних процесів. При цьому необхідним постає активізація мікробіологічної діяльності ґрунту на основі використання біологічних препаратів, таких як ризобофіт, ризогумін, діазофіт, діазобактерин, азотобактерин, ризобразин, поліміксобактерин, альбобактерин, агробактерин, фосфоентерин, які покращують умови ґрунтоутворення в агроекосистемах. Для збільшення продуктивності сільськогосподарської продукції у посушливих умовах та зниження залежності сільського господарства від  екологічних умов навколишнього середовища запропоновано використання біологічних рістрегулюючих препаратів, альтернативних джерел зрошення та дотримання  оптимальної структури сівозмін.