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1

Analysis of one-dimensional inelastic deformation of the clad layer by rolling for restoration of flat surface parts

Pham Huy-Tuan, Bulekbayeva Gulmira Zhaibergenovna, Tabylov Abzal Uteuovich, Bukayeva Amina Zakharovna, Suieuova Nabat Bazarkhanovna, Yusupov Asgerbek Alievich, Bilashova Gulmira Smagulovna, Mambetaliyeva Gulsara Sapiyevna

Journal of Machine Engineering

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2024

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Vol. 24, No. 1

87--102

EN

The hardening-finishing treatment of parts surface with rolling by steel cylindrical rollers produces low roughness, reduced residual compression stresses, and fine-grained structure due to plastic deformations. The deformation of metals during machining at high temperatures is characterized by a significant influence of strain rates on stresses. This necessitates the calculation of stresses and strains based on the equation of state of rheonic bodies. This study aims to determine the components of stresses and force factors of the technological process of finishing and strengthening machining of the surface of parts by deriving the analytical solutions to calculate the stress- strain state within the deformation zone based on creep theory. In this problem, general formulas are obtained for calculating the stress-strain state, pressure and friction forces on the contact surface, as well as forces and moments acting on the roller. Numerical analysis using Mathcad explores the understanding of the stress-strain state in the deformation zone on the force factors of the technological process. The obtained results are beneficial for establishing the mode of thermomechanical processing and selecting appropriate technological equipment for restoring flat surface parts.

2

Microstructure and Properties Evaluation of Ductile Cast Iron Subjected to Hot Plastic Deformation and Ambient Temperature Compression

Chaus Alexander S., Čaplovič Ľubomír, Pokrovskii Artur I., Sobota Robert

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

639--648

EN

The as-cast microstructure of ductile cast iron (DI) was investigated using light microscopy (LM) and SEM techniques. Further the influence of hot plastic extrusion at 1000°C with plastic strain in the range of 20-60-80% on the transformation of the as-cast microstructure and on the mechanical properties was studied. Besides this, the microstructure of DI subjected to hot extrusion after the fracture of the corresponding samples induced by compression tests was thoroughly investigated. It was found that compression had a dramatic influence on a shear deformation and hence shear fracture of the compressed samples. It was shown that the shear fracture of the hot deformed ductile iron is accompanied by the occurrence of a narrow zone of severe plastic deformation. The fracture surfaces of the extruded samples subjected to the tensile tests and the compression tests were examined.

3

Adhesion of titanium coatings applied by cold spraying on selected metal substrates

Makrenek M.

Archives of Materials Science and Engineering

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2023

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Vol. 123, nr 2

49--54

EN

Purpose: Measurement of the adhesion of a Ti coating applied by cold spraying on metal substrates with different elastic modulus. An attempt to analytically describe the experimental results, considering cold gas spray parameters such as working gas, pressure p and temperature T. Design/methodology/approach: Ti coating was sprayed on flat bars made of metal: copper, magnesium, brass, titanium, Al 7075, Al 2024 and steel with dimensions of 4x50x400 mm. All coatings were applied under the same spray conditions (p = 3.8 MPa, T = 800ºC, spray distance l = 50 mm, and spray spead V = 400 mm/s). The state of plastic deformation of coatings and substrates was examined using optical methods, and the adhesion strength was measured with the POSITEST tester. Findings: The experimental results are presented graphically. The adhesion force as a function of the relative modulus of elasticity showed a maximum. At this time, the mutual penetration depth of the coating and the substrate showed a minimum. The extremes of the relationships mentioned above occurred for points where the relative modulus of elasticity took the value one. The curve described by formula (1) was fitted to the distribution of adhesion points as a function of the relative elastic modulus. The function parameter described by formula (1) is related to the spray parameters (p, T). Research limitations/implications: To achieve a better accuracy of the analytical description of the adhesion of coatings deposited with cold gas, tests should be carried out on a larger number of substrates. The validity of the presented interpretation should be checked by applying coatings from other materials. Practical implications: In coating technologies, adhesion is a key concept. A coating with high adhesion strength is used primarily in regeneration and anti-corrosion protection processes. The analytical relationship between adhesion, relative modulus of elasticity and cold gas spray parameters will significantly speed up the selection of optimal spray parameters. Cold spray technology is a cost-intensive technology, so the economic element is not without significance. Originality/value: The article presents a method for limiting the number of variables on which the quality of the applied coatings depends. The relationship between the adhesion force, the relative elastic modulus and the selected spray parameters are indicated.

4

Effect of surface integrity on fatigue life of 7075‑T6 aluminum alloy by combination of fine turning with hydrostatic deep rolling

Zhou Yongxin, Chu Xingrong, Zang Shunlai, Sun Jiao, Yang Lei, Gao Jun

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e41, 2023

EN

In this study, the 7075-T6 aluminum alloy sample was firstly prepared by fine turning(FT) process, and then the surface treatments were subjected to hydrostatic deep rolling(HDR), including constant pressure deep rolling(CPDR) and increasing pressure deep rolling(IPDR). Subsequently, the influence of surface integrity on the fatigue life of the 7075-T6 aluminum alloy is investigated by the combination of FT with HDR. The results show that the fatigue life of IPDR and CPDR samples is increased significantly by 148% and 450% compared to the FT sample in the tensile-compression fatigue test. The improved fatigue life of IPDR and CPDR samples is a result of reduced significantly surface roughness and the increase of surface compressive residual stress, surface micro-hardness and the depth of plastic deformation layer. In addition, the deeper plastic deformation layer is the main reason for the higher fatigue life of the CPDR sample than the IPDR sample.

5

Crystal plasticity elastic-plastic rate-independent numerical analyses of pollycrystalline materials

Wójcik Marta, Skrzat Andrzej, Stachowicz Feliks, Spišák Emil

Advances in Mechanical and Materials Engineering

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2023

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Vol. 40, nr 1

63--78

EN

Macroscopic analyses of plastic forming processes give only the overall description of the problem without the consideration of mechanisms of plastic deformation and the microstructure evolution. For the consideration of these processes, numerical simulations within crystal plasticity include the change of texture, anisotropy, and strain hardening of the material are used. In this paper, a crystal plasticity rate-independent model proposed by Anand and Kothari is applied for numerical analyses of polycrystalline materials. The slip was considered as the main mechanism of the plastic deformation. Basic constitutive equations of crystal plasticity for large deformation theories are presented. The selected results of elastic-plastic problems obtained using both macro- and micro- scales software for the explicit and implicit integration are featured here. The heterogeneous distribution of strain and stress in different grains are obtained, which is associated with the various crystal orientation. The crystal plasticity modelling of materials subject to plastic deformation involves not only the information about the change of a material’s shape in a macro-scale, but also describes the phenomena occurring in material in a micro-scale.

PL

Analizy makroskopowe procesów przeróbki plastycznej prezentują jedynie ogólny zarys rozważanego problemu, bez uwzględnienia mechanizmów odkształcenia plastycznego oraz ewolucji mikrostruktury. W celu rozważania procesów przeróbki plastycznej stosowane są symulacje numeryczne w ramach teorii plastyczności kryształów uwzgledniające zmianę tekstury, anizotropię oraz umocnienie odkształceniowe. W artykule zaprezentowano zastosowanie modelu Ananda i Kothari w ramach teorii plastyczności kryształów niezależnej od prędkości odkształcenia do rozwiązywania analiz numerycznych dla materiałów polikrystalicznych. W badaniach uwzględniono poślizg dyslokacyjny jako główny mechanizm odkształcenia plastycznego. Zaprezentowano wybrane rezultaty dla problemów sprężysto-plastycznych uzyskane zarówno w skali makro, jak i mikro- dla całkowania typu explicit i implicit. Uzyskano niejednorodny rozkład naprężenia i odkształcenia w poszczególnych ziarnach, związany z różną orientacją kryształów. Modelowanie numeryczne zzastosowaniem teorii plastyczności kryształów dla materiałów poddanych plastycznemu odkształceniu dostarcza nie tylko informacje o zmianie kształtu materiału w skali makro, ale także opisuje zjawiska zachodzące w materiale w skali mikro-.

6

Influence of multi extrusion die process on mechanical and chemical behavior of 2024-T3 alloy

Razooqi Ahmed Ibrahim, Abbas Naseer M., Ghazi Sara Saad

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 3

163--170

EN

In this paper, a cold multi-pass extrusion process for a 15mm in diameter solid 2024-T3 aluminum alloy rod was carried out using three dies to obtain three different diameters of 14mm, 13mm, and 12mm. The microstructure, hardness, and corrosion behavior were investigated before and after the extrusion process. Load-Displacement data were recorded during each extrusion process. The electrochemical corrosion test was made in a 3.5 wt.% NaCl solution using potentiostat instrument under static potentials test. Corrosion current was recorded to determine the corrosion rate for specimens. The results showed that the extrusion load increased with the number of extrusion passes, which is also seen in hardness test results. In addition, the corrosion rate decreased with the increase in the number of extrusion passes. This is due to severe plastic deformation, which generates a fine grain structure of (AlCu) and (AlCuMg) components.

7

An Elastic-Plastic Analysis of Polycrystalline Structure Using Crystal Plasticity Modelling – Theory and Benchmark Tests

Wójcik Marta, Skrzat Andrzej

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 5

163--177

EN

Numerical simulations of tension and shear tests for a polycrystalline, anisotropic material were performed using crystal plasticity theory. The slip was considered here as the main mechanism of plastic deformation. Constitutive equations to describe the elastic-plastic deformation caused by the slip are presented. The generation and meshing of various shapes geometries (cubic and paddy shapes) with randomly-orientated grains by means of open source program NEPER program was shown. The Voronoi tessellation was used in order to include morphological properties of a crystalline material. The selected results of elastic-plastic analyses (stress, strain distributions and the macroscopic stress-strain resulting from homogenization) are presented here. The results obtained show the non-uniform distribution of stress and strain for different grains associated with their crystal orientation. The crystal plasticity finite element modelling of materials subjected to plastic deformation is important for microstructure-based mechanical predictions, as well as for the engineering design and to perform simulations involving not only the change of a material’s shape at a macro level but also the phenomena occurring in material in a micro-scale.

8

Influence of plastic deformation carbon steel on the process of burning electric arc

Vakulenko Igor Alex, Plitchenko Sergey, Kurt Bulent, Askerov Hangardas, Proydak Svetlana, Erdogdu Ahmet Emrah

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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z. 112

211--218

EN

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

9

Effect of Deformation Temperature on the Magnetic Properties of PrFeB Alloy Fabricated by Gas Atomization

Cho Ju-Young, Song Myung-Suk, Choa Yong-Ho, Kim Taek-Soo

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

955--958

EN

To form the fine micro-structures, the Pr17Fe78B5 magnet powders were produced in the optimized gas atomization conditions and it was investigated that the formation of the textures, microstructures, and the changes in the magnetic properties with increasing the deformation temperatures and rolling directions. Due to the rapid cooling system than the casting process, the homogenous microstructures were composed of the Pr-rich and Pr2Fe14B without any oxides and α-Fe and enables grain refinement. The pore ratios were 2.87, 1.42, and 0.22% at the deformation temperatures of 600, 700, 800°C, respectively in the rolled samples to align the c-axis which is the magnetic easy axis. Because Pr-rich phase cannot flow into the pore with a liquid state at low temperature, the improvement of pore densification was gradually observed with increasing deformation temperature. To confirm the magnetic decoupling effects of Pr2Fe14B phases by Pr-rich phases, the magnetic properties were investigated in rolled samples produced at the deformation temperature of 800°C. Although the remanent field is slightly decreased by 30%, the coercivity fields increased by about 2 times than that previous casted ingot. It is suggested that the gas atomization method can be suitable for fabricating grain refined and pure PrFeB magnets, and the plastic deformation conditions and rolling directions are a critical role to manipulate microstructure and magnetic properties.

10

Mechanical and thermal stability of retained austenite in plastically deformed bainite-based TRIP-aided medium-Mn steels

Kozłowska Aleksandra, Grajcar Adam, Janik Aleksandra, Radwański Krzysztof, Krupp Ulrich, Matus Krzysztof, Morawiec Mateusz

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

807--820

EN

Advanced medium-Mn sheet steels show an opportunity for the development of cost-effective and light-weight automotive parts with improved safety and optimized environmental performance. These steels utilize the strain-induced martensitic transformation of metastable retained austenite to improve the strength–ductility balance. The improvement of mechanical performance is related to the tailored thermal and mechanical stabilities of retained austenite. The mechanical stability of retained austenite was estimated in static tensile tests over a wide temperature range from 20 °C to 200 °C. The thermal stability of retained austenite during heating at elevated temperatures was assessed by means of dilatometry. The phase composition and microstructure evolution were investigated by means of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy techniques. It was shown that the retained austenite stability shows a pronounced temperature dependence and is also stimulated by the manganese addition in a 3–5% range.

11

Correlation between Tensile Deformation Behavior and Microstructural Morphology of Nuclear Grade Austenitic Stainless Steel Welded Joints using Infrared Thermography Technique

Rajasekaran R., Lakshminarayanan A. K., Menaka M.

Welding Technology Review

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2020

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R. 92, nr 1

7--15

EN

Tensile deformation behavior of nuclear grade Austenitic Stainless Steel (SS) and its welded joints fabricated by Gas Tungsten Arc Welding (GTAW) and Activated Flux Gas Tungsten Arc Welding (AGTAW) processes were studied and correlated with relevant microstructural morphologies using Infrared Thermography (IRT) technique. The microstructure of base metal showed a complete austenite phase. GTAW Fusion Zone (FZ) exhibited both primary ferrite and primary austenite mode of solidification. Meantime, AGTAW FZ exhibited only primary austenite mode of solidification. A strain rate of 4.4x10-4 s-1 was used during the tensile test of the base metal and welded joints. The failure locations of the base metal, GTAW and AGTAW samples were noticed at the center of the gauge portion, the base metal side away from Fusion Line (FL) and Heat Affected Zone (HAZ) respectively. The temperature variations of the base metal and weld zones were recorded in the form of thermograms using the IR camera at the different stages of the tensile deformation. During deformation study, peak temperature of 39.2 °C, 38.8 °C and 34 °C were observed at the base metal, GTAW and AGTAW samples respectively. The lesser peak temperature of the AGTAW sample compared to the base metal and GTAW samples indicated that the AGTAW sample undergone lesser deformation. Moreover, tensile deformation behaviours of the base metal and welded joints were correlated with their microstructural morphologies using corresponding temperature curves.

PL

W pracy zbadano zachowanie deformacji podczas rozciągania austenitycznej stali nierdzewnej i jej połączeń spawanych wykonanych metodą GTAW (Gas Tungsten Arc Welding) oraz AGTAW (Activated Flux Gas Tungsten Arc Welding), a następnie skorelowano je z odpowiednimi morfologiami mikrostrukturalnymi za pomocą termografii w podczerwieni (ang. lnfrared Thermography). Mikrostruktura materiału bazowego wykazała całkowitą fazę austenitu. Spoina GTAW wykazywała zarówno ferryt, jak i austenit, podczas gdy spoina AGTAW wykazywała jedynie austenit. Podczas próby rozciągania materiału bazowego i złączy spawanych zastosowano prędkość odkształcania o wartości 4,4x10-4 s-1. Do zerwania poszczególnych próbek doszło odpowiednio na środku próbki materiału bazowego, w linii wtopienia złącza spawanego GTAW i w strefie wpływu ciepła (SWC) złącza spawanego AGTAW. Zmiany temperatury w materiale rodzimym i poszczególnych obszarach złączy spawanych rejestrowano w formie termogramów za pomocą kamery na podczerwień, przy różnych etapach deformacji podczas rozciągania. Podczas badań odkształceń zaobserwowano maksymalne wartości temperatury: 39,2 °C, 38,8 °C i 34 °C odpowiednio w próbkach z materiału bazowego, spawanych GTAW i spawanych AGTAW. Niższa maksymalna temperatura próbki spawanej metodą AGTAW w porównaniu z pozostałymi próbkami wskazała, że uległa ona mniejszemu odkształceniu. Ponadto zachowania deformacji przy rozciąganiu materiału rodzimego i złączy spawanych zostały skorelowane z obrazami ich mikrostruktur przy użyciu odpowiednich krzywych temperatur.

12

Identification of plastic deformations in carbon steel elements using the filtered Barkhausen Noise signal

Dybała Jacek, Nadulicz Krzysztof

Vibrations in Physical Systems

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2020

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Vol. 31, nr 1

art. no. 2020106

EN

The paper presents new approach to processing the Barkhausen Noise signal in order to detect and identify plastic deformations in carbon steel. A new automatic method of Barkhausen effect signal filtration was investigated. Apart from a classical measurement of Barkhausen effect signal, for which the RMS value is assumed, the signal waveform factor was also used in analyzes. The developed approach to processing the Barkhausen Noise signal has made it possible to obtain more useful diagnostic data than those obtained from the raw signal.

13

Loading surface in the plastic and creep straining coupled with direct current

Rusinko Andrew, Varga Peter

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 1

195--207

EN

The paper is aimed to give a visual representation of the loading surface for different types of irrecoverable deformation in the electrical field. Three situations of deforming coupled with direct current (DC) are discussed: primary creep, secondary creep, and plastic deformation. Understanding the evolution of loading surface under the action of current is considered to be the necessary step pertaining to design forming processes. Therefore, the analysis of the evolution of loading surface in the electrical field and its comparison with the case of ordinary loading is the main subject of this paper.

14

Numerical simulation of plastic deformation in direct-drive friction welding of AISI 4140 and ASTM A106 steel tubes

Khosrowshahi J. Hashemi, Sadeghi M. H., Rasti A.

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 4

268--280

EN

Direct-drive friction welding of ASTM A106 and AISI 4140 steel tubes has been investigated both experimentally and numerically. A remeshing technique was implemented to accurately simulate highly distorted flashes during the FE simulation. The results revealed that the circumferential thermal expansion led to a higher contact pressure at the inner diameter of the interface and consequently, inner flashes were formed up to 18% larger than the outer ones. The maximum temperature was also located at the outer diameter of the interface in the first moments of the process, then it moved towards the center of the section where there was a balance between the higher slipping rate at the outer section and greater pressure at the inner section of the joint. Validation tests showed the capability of the FE model in terms of temperature, flash cross-section, and axial shortening with the maximum difference of 18.6%.

15

Prediction of magnetic properties of a plastically deformed steel and one way to measure its plastic deformation

Sablik M. J.

Advances in Materials Science

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2020

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Vol. 20, nr 2(64)

5--13

EN

In this paper, we use a phenomenological model based on the Jiles-Atherton-Sablik model of stress affecting the magnetic hysteresis of magnetic materials as modified when stress goes past the yield stress. We use this to show that (1) the model produces sharp shearing of hysteresis curves, as seen experimentally and that (2) it also produces a step in the hysteresis loss at small residual plastic strain. We also find that the step in the hysteresis loss can be fitted to a power law, and find that the power law can be fitted by the power m=0.270, different from the mechanical Ludwik Law exponent, and reasonably close to the experimental 0.333 and 0.202. We will also suggest a method of measuring how plastically deformed the material is by suggesting how the dislocation density can be measured.

16

Achievements in micromagnetic techniques of steel plastic stage evaluation

Campos M. F. de

Advances in Materials Science

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2020

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Vol. 20, nr 1(63)

16--55

EN

The investigation of plastic deformation and residual stress by non-destructive methods is a subject of large relevance for the industry. In this article, the difference between plastic and elastic deformation is discussed, as well as their effects on magnetic measurements, as hysteresis curve and Magnetic Barkhausen Noise. The residual stress data can be obtained with magnetic measurements and also by the hole drilling method and x-ray diffraction measurements. The residual stress level obtained by these three different methods is different, because these three techniques evaluate the sample in different depths. Effects of crystallographic texture on residual stress are also discussed. The magnetoelastic term should be included in micromagnetic methods for residual stress evaluation. It is discussed how the micromagnetic energy Hamiltonian should be expressed in order to evaluate elastic deformation. Plastic deformation can be accounted in micromagnetic models as a term that increases the coercive field in soft magnetic materials as the steels are.

17

The 2D characterization of pores shape in sintered material before and after deformation

Chrapoński Jacek, Roskosz Stanisław, Madej Łukasz

Inżynieria Materiałowa

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2019

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Vol. 40, nr 4

98--102

EN

The specimens sintered from Distaloy AB iron powder have been examined to evaluate evolution of morphological characteristics under complex deformation conditions. The sintering procedure, in particular, the pressure and the temperature have been adjusted in order to obtain about a 15% porosity level. All examinations were performed on the specimen in as-sintered state, as well as after plastic deformation (compression with cyclic torsion). The volume fraction and pores shape have been described quantitatively before and after deformation. On the basis of statistical analysis, it was found that compression with cyclic torsion with amplitude 3° and frequency 0.5 Hz better reduce porosity than deformation with amplitude 6° and frequency 1 Hz. All shape factors that were used to describe pores geometry, except convexity, differ significantly after plastic deformation in comparison to values before deformation. The Principal Component Analysis of the pores shape factors showed, that it is possible to reduce the characterization of the pores to two principal components. Alternatively, it is sufficient to fully characterize pores shape with three shape factors: circularity, Malinowska’s factor and not correlated with them aspect ratio.

PL

Właściwości materiałów porowatych silnie zależą od cech geometrycznych porów: ich objętości względnej, wielkości, kształtu, rozmieszczenia itp. Odkształcenie plastyczne materiałów porowatych jest procesem, który zmienia ich właściwości, również wskutek zmiany cech porowatości. W trakcie odkształcenia plastycznego morfologia i liczba porów zmienia się, wpływając na właściwości materiału. Kontrola i możliwość kształtowania właściwości materiałów porowatych wymaga wiedzy dotyczącej zmian morfologii porów, przede wszystkim kształtu określanego na podstawie pomiarów na obrazach mikrostruktury zarejestrowanych podczas badań zgładów metalograficznych. Celem pracy było określenie zmian objętości względnej i kształtu porów po ściskaniu z cykliczną rotacją spiekanych próbek oraz dobór współczynników kształtu porów najlepiej charakteryzujących morfologię porów po odkształceniu plastycznym.

18

Wpływ ściskania na mikrostrukturę i twardość stali wysokomanganowej

Tomaszewska Agnieszka, Jabłońska Magdalena, Tkocz Marek

Hutnik, Wiadomości Hutnicze

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2019

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Vol. 86, nr 3

72--76

PL

Aktualnie wiele ośrodków badawczo-naukowych koncentruje swe prace w obszarze nowych stali wysokomanganowych z grupy AHSS. Stale te mogą stać się konkurencyjne w stosunku do stosowanych, tradycyjnych materiałów metalicznych. Występująca w tych stalach synergia właściwości mechanicznych stanowi nową jakość w stalowych materiałach konstrukcyjnych i istotnie zmienia możliwości projektowania i wytwarzania elementów konstrukcyjnych pojazdów mechanicznych. W pracy dokonano oceny struktury i właściwości dwóch gatunków stali wysokomanganowej austenityczno- ferrytycznej po odkształceniu plastycznym. Stale posiadały zróżnicowaną zawartość węgla, manganu i aluminium. Celem pracy było określenie wpływu parametrów odkształcenia w procesie ściskania na właściwości obu gatunków stali. Analizę struktury przeprowadzono wykorzystując techniki mikroskopii świetlnej i skaningowej. Oceny właściwości dokonano na podstawie pomiarów twardości.

EN

Recently many research centres focus in the area of new high manganese steel from the AHSS group. These steels can become competitive in relation to the traditional, metallic materials used. The synergy of mechanical properties existing in these steels constitutes a new quality in steel construction materials and significantly changes the possibilities of designing and manufacturing of construction elements of motor vehicles. In the paper, two grades of high-manganese steels after a plastic deformation were studied. Steel grades with an austenitic-ferritic structure with various contents of carbon, manganese and aluminum were selected for the studies. The main goal of the work was to determine the influence of deformation parameters on the properties of both examined steel grades. The structural analysis was carried out using optical and scanning microscopy techniques. The properties were evaluated on the basis of hardness measurements.

19

The Effect of the Asymmetrical Rolling Process on Structural Changes in Hot-Rolled Bimetal Sheets

Rydz D., Koczurkiewicz B., Stradomski G., Garstka T., Wypart J.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 4

1495--1501

EN

The paper presents research results on the selection of parameters for the asymmetric rolling process of bimetallic plates 10CrMo9-10+X2CrNiMo17-12-2. They consisted in determining the optimum parameters of the process, which would be ensured to obtain straight bands. Such deformation method introduces in the band the deformations resulting from shear stress, which affect changes in the microstructure. But their effect on the structure is more complicated than in the case of homogeneous materials. It has been shown that the introduction of asymmetric conditions into the rolling process results in greater grain refinement in the so-called hard layer. There was no negative effect on the structural changes in the soft layer observed.

20

Numerical and Experimental Modeling of Plastic Deformation the Multi-Layer Ti/Al/Mg Materials

Mróz S., Stefanik A., Szota P., Kwapisz M., Wachowski M., Śnieżek L., Gałka A., Szulc Z.

Archives of Metallurgy and Materials

|

2019

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Vol. 64, iss. 4

1361--1368

EN

The paper has presented the results of theoretical studies and experimental tests of the plastic deformation of multi-layered Ti/Al/Mg specimens. Theoretical studies were carried out using the Forge2011® computer program. Physical modeling, on the other hand, was performed using the Gleeble3800 simulator. Cuboidal specimens were cut off from the plates obtained in the explosive welding method. Based on the obtained investigation results it has been found non uniform deformation of the particular layer as a result their different value of flow stress.