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1

Microstructure and selected mechanical properties of hot-rolled AA2024/SiC composite manufactured by powder metallurgy

Nikiel Piotr, Kutyła Patrycja

Composites Theory and Practice

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2025

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R. 25 nr 2

102-112

EN

This study investigates the microstructure and mechanical properties of an AA2024/SiC composite produced using powder metallurgy, followed by hot extrusion and multi-pass hot rolling. The composite, containing 5 wt% SiC, was fabricated by hot pressing at 450°C, then extruded and rolled with reductions of up to 66.2%. Microstructural analysis revealed uniform distribution of the SiC particles, grain refinement due to dynamic recrystallization (DRX), and enhanced particle dispersion with increasing rolling reduction. The hardness measurements showed significant improvement, with values increasing from 91 HV1 in the extruded state to 112 HV1 after the final rolling pass, and further grew to 151 HV1 after heat treatment. The tensile tests confirmed a strengthening effect, with the yield stress and ultimate tensile strength rising with rolling reduction from 205 MPa and 304 MPa (after initial rolling) to 236 MPa and 352 MPa (after the final rolling), respectively. Solution treatment and aging of the rolled composite resulted in a sharp increase in yield stress and ultimate tensile strength, reaching 293 MPa and 431 MPa after the first pass, increasing to 375 MPa and 484 MPa after the final pass. The study concludes that hot rolling significantly enhances the mechanical performance of AA2024/SiC composites, with grain refinement and particle fragmentation playing key roles in the strengthening mechanisms.

2

Formation of concavities on the ends of parts manufactured on CNC skew rolling mills

Pater Zbigniew, Bulzak Tomasz, Tomczak Janusz, Shu Xuedao, Xia Yingxiang

Archives of Civil and Mechanical Engineering

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2025

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Vol. 25, no. 1

art. no. e8, 2025

EN

This study investigates the problem of concavity formation on the ends of parts manufactured on CNC skew rolling mills. Numerical modeling and Taguchi method were used to determine the effects of the main parameters of skew rolling (i.e., forming angle, skew angle, reduction ratio, temperature, steel grade, dimeter ratio, velocity ratio) on the depth of concavities formed on the product ends. The simulations showed that the only parameter to have a significant impact on the concavity depth was the reduction ratio. The FEM results were then used to establish equations for calculating concavity depth and allowance for excess material with concavity. For more universality, the established equations took into account the billet diameter. The experimental validation showed high agreement between the numerical and the experimental concavity depths.

3

Effect of ultrasonic surface rolling process on the fatigue performance of the 7075 aluminum alloy

Zou Chungai, Jiang Yun, Yang Ming, Guan Qinkai, Chen Peng, Nie Jiangping

Archives of Civil and Mechanical Engineering

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2025

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Vol. 25, no. 1

art. no. e10, 2025

EN

The impact of the gradient nanostructures on the fatigue properties of aluminum alloys remains limited. The ultrasonic surface rolling process (USRP) was utilized in this study to generate the gradient nanostructure on the surface of 7075 aluminum alloy, and the high fatigue properties with the stress ratio R = – 1 were following tested. The findings indicated that the fatigue limits of 3- and 6-passes-treated samples were found to reach 225 MPa (125%) and 200 MPa (100%), respectively, surpassing those of untreated sample. The characterizations of scanning electron microscope (SEM), laser confocal scanning microscope (LCSM), and X-ray diffractometer (XRD) showed a positive correlation between the number of rolling passes and the enhancement of the gradient hardening layer and residual compressive stress, contributing to the improvement in fatigue limit. Meanwhile, the SEM analysis of the fracture indicated that the fatigue crack initiation site was altered as a result of surface modification, and the crack initiation point of the 3-passes-treated sample was located further from the surface. Additionally, finite-element simulation was employed to analyze the stress distribution across the cross-section, and the fatigue risk coefficient Rf was used to quantify the impact of residual stress distribution and surface hardening on the crack initiation site. The results demonstrated that USRP not only altered the surface condition of the aluminum alloy but also changed its stress distribution in the cross-section. The combined effect of the two controlled the crack initiation site and the fatigue life of the 7075 aluminum alloy.

4

Modernisation of the drop forging process on the example of forming a bracket forging

Pater Zbigniew

Mechanik

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2024

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R. 97, nr 3

6--10

EN

This paper presents an example of the manufacturing of bracket forgings formed in a dual system. Cross-wedge rolling (CWR) was proposed as the forming method for the preform. The correctness of the adopted solution was verified in numerical simulations, which were performed using the commercial software Forge®. It was shown in detail how the shape of the workpiece changes in the individual operations of the forming process. Maps of temperature, effective strain, strain rate in the preform as well as distributions of force parameters in the rolling process are presented.

PL

W artykule przedstawiono przykład wykonywania odkuwek wspornika kształtowanych w układzie podwójnym. Jako metodę wytwarzania przedkuwki zaproponowano walcowanie poprzeczno-klinowe (WPK). Poprawność przyjętego rozwiązania zweryfikowano w symulacjach numerycznych, które wykonano w komercyjnym programie Forge®. Szczegółowo pokazano, jak zmienia się kształt przedmiotu obrabianego w poszczególnych operacjach procesu kształtowania. Przedstawiono mapy temperatury, intensywności odkształcenia, prędkości odkształcenia w przedkuwce oraz rozkłady parametrów siłowych w procesie walcowania.

5

Study on the microstructure and technological properties of clad plates made of steels S235jR and X20Cr13 and S235jR and X5CrNi18-10 after hot rolling

Walnik Bartłomiej, Woźniak Dariusz, Adamczyk Mariusz, Palus Rafał, Bagińska Aleksandra

Materials Science and Welding Technologies / Technologie Materiałowe i Spawalnicze

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2024

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Vol. 68, No. 3

art. no. 1

EN

The article presents the results of physical experiments consisting in the rolling of layered plates (clad plates). The experiments involved two types of two-layered flat bars, i.e. S235JR and X20Cr13 as well as S235JR and X5CrNi18-10. The experiment resulted in the development of a technology for the fabrication of layered flat bars made of structural steel S235JR, corrosion-resistant steel X20Cr13 and austenitic acid-resistant steel X5CrNi18-10. Microstructural observations were performed using a light microscope (LM) and a scanning electron microscope (SEM). The observations revealed the possibility of obtaining permanent joints through hot rolling and the possibility of applying steel grades S235JR, X20Cr13 and X5CrNi18 in the fabrication of layered plates.

PL

W artykule omówiono wyniki fizycznych eksperymentów walcowania blach warstwowych. Eksperymenty wykonano na dwóch rodzajach płaskowników dwuwarstwowych S235JR – X20Cr13 i S235JR – X5CrNi18-10. Wynikiem eksperymentów było opracowanie technologii wytwarzania płaskowników o budowie warstwowej, złożonych ze stali konstrukcyjnej S235JR oraz ze stali odpornej na korozję X20Cr13 i stali kwasoodpornej austenitycznej X5CrNi18-10. Badania mikrostruktury przeprowadzono przy użyciu techniki mikroskopii świetlnej i skaningowej mikroskopii elektronowej, SEM. Wyniki pracy wskazują, że dobrane parametry walcowania na gorąco pozwoliły na wytworzenie trwałego połączenia pomiędzy blachami w wyniku ich walcowania na gorąco i na możliwość zastosowania stali z gatunków S235JR, X20Cr13 i X5CrNi18 na blachy warstwowe.

6

Analysis and study of rolling parameters of coils on an inclined plane

Gumeniuk Larysa, Fedik Lesya, Didukh Volodymyr, Humeniuk Pavlo

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2024

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T. 14, nr 3

101--104

EN

In the article, the patterns of movement of rolls of long-fiber plant crops on an inclined plane are investigated. Experimental data on determining the rolling time of rolls on an inclined plane with angles of inclination of 25° and 10° to the horizon for rolls of different mass and radius are processed. An analysis and investigation of the patterns of movement of these rolls have been carried out, including angular velocity, velocity of roll centers, rotation angle, and kinetic energy of the rolls.

PL

W artykule zbadano wzorce ruchu zwojów roślin długowłóknistych na pochyłej płaszczyźnie. Przetworzono dane eksperymentalne dotyczące określania czasu walcowania zwojów na pochyłej płaszczyźnie o kątach nachylenia 25° i 10° do horyzontu dla zwojów o różnej masie i promieniu. Przeprowadzono analizę i badanie wzorców ruchu tych zwojów, w tym prędkości kątowej, prędkości środków zwojów, kąta obrotu i energii kinetycznej.

7

Characterization of High Pressure Water Descaling Jets for Slabs Based on Different Shape Factors

Yang Bowen, Liu Guangqiang, Xu Chengcheng, Liu Kun, Han Peng

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 1

121--128

EN

The surface temperature of steel billets during hot rolling can reach up to 1200°C. High temperature promotes rapid oxidation of the surface of steel billets, forming a dense oxide layer similar to fish scales. If not removed in a timely manner, it will damage the surface of the steel billets and exacerbate the wear of the rolls during the descaling process. There are many methods for descaling, but high-pressure water jet has become the main method for descaling due to its excellent descaling performance, low cost, and ease of use. The tip of the descaling nozzle serves as the main component, and its structural parameters affect the final descaling effect. This research changes the shape factor of the nozzle groove curve and the diameter of the nozzle throat, and performs computational fluid dynamics (CFD) simulations on the simplified nozzle external flow field. The axial velocity at the center of the jet generates a velocity peak at 0.5-1 Dc. The peak velocity increases with the increase of shape factor and throat diameter, and the influence of shape factor on the peak velocity is greater. For a constant target distance, the length of the velocity stable section along the jet impact line increases with the increase of the shape factor. The maximum value of dynamic pressure increases, and the smaller the target distance, the greater the dynamic pressure difference. The trend of water volume is roughly the same as that of dynamic pressure.

8

The influence of the rolling method on cold forming ability of explosive welded Ti/steel sheets

Motyka Maciej, Mróz Sebastian, Więckowski Wojciech, Stefanik Andrzej, Ziaja Waldemar, Poręba Marek, Adamus Janina

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 3

art. no. e191, 2024

EN

Products made of clad sheets are a cost-effective alternative to products made entirely of cladding material. The cladding process aims to enhance functional properties, such as corrosion resistance and tribological properties, or modify mechanical properties and conductivity. This publication analyzes the influence of the rolling method on the cold forming ability of explosive welded Ti/steel sheets. Special attention was paid to the quality of the connection between the sheets, as it significantly impacts clad sheet formability. The drawability of these clad sheets was assessed based on the mechanical and technological properties, as well as through microstructural analyses. Experimental analyses revealed that hot rolling of the clad leads to the disappearance of the wave character of the interface and formation in its area of the Frenkel plane and interface layer, which significantly affect the mechanical and technological properties of the analyzed clad. Better cold forming ability, especially in reverse bend test, were obtained for asymmetrically rolled clad, which exhibits greater uniformity of structure.

9

Study of CNC skew rolling of hollow rail axles with a mandrel

Bulzak Tomasz, Pater Zbigniew, Tomczak Janusz, Wójcik Łukasz

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 3

art. no. e145, 2024

EN

The manuscript presents a new manufacturing technology for the production of hollow railway axle forgings. The manufacturing technology analyzed is based on three-roll skew rolling (TRSR) using a computer numerically controlled (CNC) rolling mill. The study focused on comparing the rolling capability of hollow products without and with a mandrel calibrating the hole of the forging. The influence of tube billet size on the rolling process was also analyzed. FE analysis and experimental studies were carried out. An analysis of the accuracy of the internal hole of the forging depending on the adopted parameters of the rolling process was carried out. Based on numerical simulations, the state of strain and the flow pattern of the material and temperature distribution during rolling were determined. The force parameters of the rolling process of hollow forgings were also analyzed. Based on the research, a two-stage rolling technology for rolling hollow railway axle forgings was proposed. The results obtained indicate the suitability of using a calibrating mandrel to improve hole accuracy in hollow forgings rolled from a tubular billet. The gap c between the bore diameter of the forging and the diameter of the mandrel was measured. Increasing the tubular billet dimensions from Ø42.4 × 10 mm to Ø48.3 × 12.5 mm reduced the gap c by 49.8%. Rolling the billet Ø51 × 14.2 mm in two passes compared to rolling in one pass reduced the gap c by 45.5%.

10

Strong strain‑hardening capability in plain carbon steel through cold rolling and heat treatment of lamellar structure

Talebi Fatemeh, Jamaati Roohollah, Hosseinipour Seyed Jamal

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 1

art. no. e44, 2024

EN

In the current research, strong strain-hardening capability in 1045 carbon steel was achieved by cold rolling and heat treatment of the lamellar structure. After 60% cold rolling, the proeutectoid ferrite and pearlite were severely elongated along the rolling direction. Cementite layers with brittle nature were fragmented under the action of stress and also by shear band formation during rolling. The lamellar heterogeneous microstructure of the heat-treated samples was formed by the proeutectoid ferrite as the soft domain and the pearlite as the hard domain. Increasing the heat treatment duration promoted the spheroidization transformation of cementite, and the spheroidization degree of cementite increased. With the increase in the time of heat treatment, the number of recrystallized grains is increased. Heat treatment led to weakening the deformation texture (⟨100⟩‖ND or θ fiber) and strengthening the recrystallization texture (⟨110⟩‖ND or ζ fiber). The heat-treated steels revealed an average microhardness value much higher than its macrohardness due to changes in the texture of ferrite grains. Heat treatment decreased the strength and hardness, and increased the ductility and toughness of steel compared to the cold-rolled sample owing to the annihilation of dislocations and the strengthening transition from strain hardening to grain refinement. The heat-treated samples exhibited a wider range of uniform plastic deformation and a larger strain hardening rate than the cold-rolled sample owing to the occurrence of the recovery of strain hardening rate phenomenon. The appropriate collocation of the fine spherical cementite and the soft/hard domains (with a large difference in mechanical properties) was beneficial to obtaining excellent strength-ductility balance in plain medium carbon steel. After heat treatment, the extent of ductile fracture considerably increased. With increasing the time of heat treatment from 1 to 3 h, the number of lamellar dimples decreased owing to the creation of more fine spherical cementite

11

Effect of warm forming process parameters on 42CrMo4 skew rolled bar mechanical properties and microstructure

Murillo-Marrodán Alberto, Bulzak Tomasz, García Eduardo, Derazkola Hamed Aghajani, Majerski Krzysztof, Tomczak Janusz, Pater Zbigniew

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 2

art. no. e90, 2024

EN

Skew rolling is a manufacturing process in which two or three rolls are used to reduce the diameter or modify the shape of a cylindrical workpiece, which is used to manufacture mechanical components such as shafts, rods or balls. Hot conditions are used to overcome limitations related to material ductility, residual stress and machine capacity. In this paper, the warm skew rolling (WSR) process of 42CrMo4 rods is modeled by the finite element method. The effects of forming parameters, namely initial temperature and roll rotational velocity, on the material strain rate, thermal properties, microstructure and hardness were analyzed. Simulation results were validated by experimental process data, while hardness tests and SEM-EBSD microscopy were used to assess mechanical properties and microstructure, respectively. The WSR resulting microstructure is different from the normalized ferritic-pearlitic initial one. The degree of spheroidization (DoS) of cementite increases with temperature. The maximum DoS of 86.5% occurs at the initial temperature of 750 °C, leading to the highest material softening. Rolling from lower temperatures favors grain fragmentation and the achievement of incomplete spheroidization, which, in combination with the highest proportion of high-angle boundaries, contributes to a higher hardness of the rods with respect to those rolled at higher temperatures. The highest reduction in hardness takes place at 750 °C and 30 rpm, leading to 209.4 HV1 (30.7% reduction) and 194.1 HV1 (35.7% reduction) in the near-surface and internal regions, respectively. The driving factor is the transformation of cementite precipitates into a spheroidal form characterized by the greatest degree of dispersion.

12

A WOA‑BP neural network microstructure evolution prediction model of TC11 titanium alloy and application in hollow shaft during cross wedge rolling with mandrel

Yin Jian, Yang Cuiping

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 2

art. no. e96, 2024

EN

The mechanical properties of TC11 titanium alloy parts are closely related to their microstructure, and a study of the microstructure evolution during cross wedge rolling (CWR) can be beneficial for mechanical property regulation. In this paper, a WOA-BP neural network prediction model was developed and utilized to investigate the microstructure evolution of the TC11 titanium alloy hollow shaft during CWR with mandrel. Firstly, the effect of process parameters on the alpha phase grain size of TC11 titanium alloy was investigated through hot compression tests at temperatures ranging from 850 to 950 ℃, and the grain size under different conditions was obtained. Accordingly, a WOA-BP microstructure prediction model was established utilizing the whale optimization algorithm. Then, the microstructure prediction model was embedded into the software Simufact through the secondary development techniques to forecast the alpha phase grain size in the hot compression experiment and the CWR hollow shaft experiment. Finally, the CWR TC11 alloy hollow shaft experiments were conducted. The maximum error between the experiment and the predicted results is 11.07%, which means the model can accurately predict the alpha phase grain size of TC11 alloy. The results indicated that the established model can effectively predict the alpha phase grain size during CWR. Additionally, the model was used to predict the alpha phase grain size of TC11 alloy hollow shaft at different stages of CWR with mandrel.

13

A review on the effect of various rolling regimes (cryo, cold, warm, hot) and post‑annealing on high‑entropy alloys: microstructure evolution, deformation mechanisms, and mechanical properties

Tayyebi Moslem, DerakhshaniMolayousefi Mahdi

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 1

art. no. e16, 2024

EN

Despite their complex composition, high-entropy alloys (HEAs) have a simple structure and have been extensively researched for their ability to achieve unique properties through thermo-mechanical processing (TMP). This review studies the effects of different rolling regimes and post-annealing on single and multiphase HEAs, analyzing how TMP leads to microstructural changes and improved mechanical properties. The rolling changes the shape and utilizes different mechanisms determined by the rolling temperature to strengthen the raw materials, thus affecting the HEAs' properties. The microstructural evolution of HEAs during annealing is affected by various parameters such as annealing time, annealing temperature, and heating rate, which impact the strength–ductility combination of HEAs. According to the literature, cryogenic rolling (cryo-rolling), as opposed to cold rolling, provides greater strengthening. This is due to the faster microstructural evolution kinetics in cryo-rolling. Thus, cryo-rolling enhances the strengthening by activating deformation twinning at earlier stages through the intersection of twins and more shear banding, which is preferred to microbands for HEAs with low stacking fault energy (SFE). Rolling at high temperatures is the most suitable approach for HEAs with low workability. Warm and hot rolling enable microstructure evolution through deformation mechanisms, including grain growth, recovery, recrystallization, and phase transformation based on the process temperature. The ratio of recovery to recrystallization depends on temperaturę and SFE, with recovery dominating in alloys with high SFE and at lower rolling temperatures, while recrystallization is more prevalent for alloys with low SFE and at higher temperatures, leading to specific ductility–strength synergy.

14

Effect of Roll Force Decrease in Hot Rolling of Dp600 Steel Grade by Use of Roll Gap Lubrication

Kaźmierski Tomasz, Krawczyk Janusz

Tribologia

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2023

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nr 2

27--33

EN

The force required for plastic deformation of steel in the hot rolling process is an important parameter which impacts roll wear, strip steering in finishing stands, shape and profile of the rolled strip and energy consumption. Theoretically, the roll force could be effectively decreased by rolling strips with higher temperatures and a lower speed or by reducing the strip’s input thickness. Due to the required mechanical properties of hot rolled strips as well as the continuous drive toward increased rolling line productivity and cost optimisation, in most cases, it is impossible to lower roll force by changing these two parameters. Roll gap lubrication effectively decreases the roll force, and lowering the friction between the work roll's surface and rolled material reduces roll force by 5% to 20%. Lower roll force brings obvious results in lower energy consumption, but even more important are benefits coming from lower work roll wear and improved strip shape and profile. These issues are particularly important during the hot rolling of dual-phase steel, which due to relatively low final rolling temperature (FRT), requires a higher roll force resulting from increased steel yield stress at lower temperatures.

PL

W procesie walcowania na gorąco siła konieczna do uzyskania pożądanego stopnia odkształcenia plastycznego materiału w kotlinie walcowniczej jest istotnym parametrem, wpływającym na stopień zużycia walców, prowadzenie pasma w klatkach walcowniczych, kształt i profil walcowanego pasma oraz zużycie energii elektrycznej. Efektywnymi sposobami zmniejszenia siły koniecznej do odwalcowania pasma w grupie klatek wykańczających mogłoby być prowadzenie walcowania w wyższej temperaturze i z mniejszymi prędkościami lub zmniejszenie wejściowej grubości pasma. Z uwagi na wymagane własności mechaniczne blachy po walcowaniu na gorąco, a także ciągłe dążenie do zwiększenia wydajności linii i optymalizacji kosztów, najczęściej nie jest to możliwe. Skutecznym sposobem pozwalającym na zmniejszenie siły walcowania jest zastosowanie smarowania kotliny walcowniczej. Zmniejszenie tarcia pomiędzy powierzchnią walców i walcowanym materiałem pozwala uzyskać spadek siły na poziomie 5–20%. Spadek siły walcowania przekłada się wprost na zmniejszenie zużycia energii elektrycznej, jednak najważniejsze są korzyści związane ze zmniejszonym zużyciem walców roboczych i lepszą kontrolą kształtu pasma. Kwestie te nabierają szczególnego znaczenia podczas produkcji blachy o strukturze dwufazowej, która z uwagi na wymaganą stosunkowo niską temperaturę końca walcowania charakteryzuje się dużym oporem odkształcenia skutkującym występowaniem dużych sił w trakcie walcowania w grupie klatek wykańczających.

15

Analysis of the influence of kinematic and friction asymmetry on the curvature of the strip and force parameters of the rolling process

Sułek Bartosz, Krawczyk Janusz, Majewski Marcin, Ławida Natalia, Plewa Krzysztof

Tribologia

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2023

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nr 3

81--94

EN

This paper presents the numerical analysis results in Simufact Forming 2016 of the asymmetric cold rolling process of S235JR steel. The research determined the effect of kinematic asymmetry, frictional asymmetry and their combination on the strip curvature, as well as the force parameters of the rolling process. During the conducted research, the aim was to determine the parameters of the asymmetric rolling process, allowing the highest possible reduction of forces (in relation to symmetric rolling) while maintaining the curvature of the strip with an acceptable value |δ|≤1.5. For this purpose, "process maps" were developed based on the obtained results, allowing for selecting the most favourable process parameters for the different rolling reductions. In addition, the results made it possible to determine the effect of the various asymmetries obtained on the process forces and strip curvature depending on the size of the rolling reduction.

PL

W artykule przedstawiono wyniki analizy numerycznej w programie Simufact Forming 2016 procesu walcowania asymetrycznego na zimno stali S235JR. W ramach prac określono wpływ asymetrii kinematycznej, asymetrii tarcia oraz ich połączenia na krzywiznę pasma, a także parametry siłowe procesu walcowania. Podczas przeprowadzonych badań dążono do określenia parametrów procesu walcowania asymetrycznego, pozwalających na możliwie wysoką redukcję sił (w odniesieniu do walcowania symetrycznego) przy jednoczesnym zachowaniu krzywizny pasma na dopuszczalnym poziomie W tym celu opracowano na podstawie analizy uzyskanych wyników „mapy procesowe”, umożliwiające dla różnych gniotów dobór najkorzystniejszych parametrów procesu. Dodatkowo uzyskane wyniki badań pozwoliły na określenie wpływu poszczególnych asymetrii na siły procesu oraz krzywizny pasma w zależności od wielkości wprowadzonych odkształceń.

16

A roll’s wear during hot rolling of high-silicon steel and its impact on the quality of a strip’s profile

Ścibisz Kamila, Kaźmierski Tomasz, Krawczyk Janusz

Tribologia

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2023

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nr 3

95--102

EN

Hot rolling of grain-oriented high silicon steel is related to technical problems such as high temperature and long rolling campaigns with strips of the same width. Numerous methods may be carried out as a solution to these problems. Before the rolling campaign, all rolls of finishing stands are exchanged. The campaign is scheduled with additional exchanges of rolls on two last stands in two stages. A roll’s wear increases with the quantity of rolled material and may lead to strip profile deformation. Exchanging the rolls ensures the required steel quality and prevents losses caused by quality defects. This work identifies factors affecting the work roll's wear and refers to the material from which rolls are made. This work aimed to determine the wear of work rolls of the finishing group rolling mills during the rolling of high-silicon steel. The work presents wear analyses of 30 rolls. It was analysed depending on roll type and high silicon steel rolled material quantity. Compared wear of rolls after rolling high-silicon steel and black sheet. By analysing the distribution of roll wear along the length of the roll, it was found that the wear of working rolls directly affects the geometry of the rolled sheet, which may affect the quality of the strip profile of the rolled sheet.

PL

Walcowanie stali wysokokrzemowych o zorientowanym ziarnie wiąże się z problemami technologicznymi takimi jak: wysoka temperatura walcowania i bardzo długa sekwencja walcowania blachy o tej samej szerokości. Rozwiązanie tych problemów prowadzone jest wieloaspektowo. Przed rozpoczęciem procesu walcowania stali wysokokrzemowych następuje wymiana walców roboczych we wszystkich walcarkach wykańczających. Walcowanie planowane jest z przebudową pośrednią walców roboczych, w dwóch ostatnich walcarkach. Po odwalcowaniu określonej ilości materiału konieczne jest wycofanie narzędzi do regeneracji z uwagi na postępujące zużycie walców roboczych. Przebudowa pośrednia walców ma na celu zapewnienie wymaganej jakości blachy i niedopuszczenie do strat związanych z powstawaniem wad jakościowych. Niniejsza praca określa czynniki wpływające na zużycie walców, odnosząc je również do materiału, z którego wykonane są narzędzia. Celem pracy było określenie zużycia walców roboczych walcarek grupy wykańczającej podczas walcowania stali wysokokrzemowej. W pracy przedstawiono analizę zużycia 30 walców roboczych. Analizowano zużycie w zależności od rodzaju walca podczas walcowania stali wysokokrzemowej, porównano zużycie walców na poszczególnych klatkach walcowniczych w zależności od ilości przewalcowanej stali wysokokrzemowej, dokonano porównania zużycia walców po walcowaniu stali wysokokrzemowej i walcowaniu blachy czarnej. Obserwowany nierównomierny rozkład zużycia walców na ich długości może wpływać na kształt walcowanej blachy, co może przekładać się na jakość profilu poprzecznego.

17

Application of the cross-wedge rolling process to the manufacture of preforms for elongated forgings

Pater Zbigniew

Mechanik

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2023

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R. 96, nr 3

6--11

EN

The article presents two examples of the use of the cross-wedge rolling process (CWR) to form preforms into forgings for the mining industry. A novelty in the discussed rolling processes was the use of flanges, which were used to form the tapered ends of preforms. The correctness of the solutions was verified by numerical simulations using the Forge® programme. Workpiece shape progressions are presented for both rolling and drop forging. Fields of temperature, effective strain and damage function in rolled preforms are also presented. Furthermore, it is shown how radial force and torque change during rolling.

PL

W artykule opisano dwa przykłady zastosowania procesu walcowania poprzeczno-klinowego (WPK) do kształtowania przedkuwek na odkuwki dla górnictwa. Nowością w tych procesach walcowania było zastosowanie listew oporowych, za pomocą których formowano zakończenia stożkowe przedkuwek. Poprawność prezentowanych rozwiązań zweryfikowano w symulacjach numerycznych, które wykonano w programie Forge®. Przedstawiono progresje kształtu przedmiotu obrabianego zarówno podczas walcowania, jak i kucia matrycowego. Zaprezentowano także mapy temperatury, intensywności odkształcenia i funkcji zniszczenia w przedkuwkach walcowanych. Ponadto pokazano, jak podczas walcowania zmieniają się siła rozporowa i moment obrotowy.

18

Walcowanie poprzeczno-klinowe odkuwki osi kolejowej

Bulzak Tomasz, Winiarski Grzegorz, Wójcik Łukasz

Hutnik, Wiadomości Hutnicze

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2023

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Vol. 90, nr 2

16--20

PL

Artykuł przedstawia wyniki modelowania numerycznego procesu walcowania poprzeczno-klinowego odkuwek osi kolejowych. Na wstępie przedstawiono główny problem, jakim jest pękanie materiału w procesie walcowania poprzeczno-klinowego. Przedstawiono propozycję ograniczenia zjawiska pękania materiału, polegającą na zmianie konstrukcji narzędzi kształtujących. Zaprojektowano trzy warianty narzędzi, których przydatność w procesie walcowania poprzeczno-klinowego osi kolejowych została zweryfikowana na drodze symulacji numerycznych. Symulacje numeryczne przeprowadzono metodą elementów skończonych w oprogramowaniu Simufact Forming. Uzyskane wyniki nie potwierdziły przyjętych założeń. Zastosowanie narzędzi z dwoma kątami kształtującymi wpłynęło na wzrost wartości kryterium pękania, co tym samym zwiększa ryzyko pękania materiału podczas walcowania osi kolejowych.

EN

This paper presents the results of numerical modelling of the cross-wedge rolling process of railway axle forgings. The main problem of material cracking in the cross-wedge rolling process is first presented. A proposal to reduce the phenomenon of material cracking by changing the design of forming tools is presented. Three tool variants were designed, the suitability of which in the process of cross-wedge rolling of railway axles was verified by means of numerical simulations. Numerical simulations were carried out using the finite element method in the Simufact Forming software. The results obtained did not confirm the assumptions made. The use of tools with two forming angles increased the value of the fracture criterion, thereby increasing the risk of material fracture during rolling of railway axles

19

Asymetryczne walcowanie poprzeczno-klinowe

Wójcik Łukasz, Bulzak Tomasz

Hutnik, Wiadomości Hutnicze

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2023

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Vol. 90, nr 3

6--10

PL

W pracy przedstawiono wyniki badań numerycznych procesu asymetrycznego walcowania poprzeczno-klinowego. Do przeprowadzenia symulacji komputerowej wykorzystano program Simufact.Forming 2021. Wykonano analizę numeryczną trzech przypadków walcowania poprzeczno-klinowego przeprowadzonych z wykorzystaniem trzech kompletów narzędzi różniących się geometrią. Jako wsad zastosowano pręt o średnicy Ø40 mm oraz długości 92 mm wykonanych ze stali gatunku C45. Na podstawie przeprowadzonej symulacji komputerowej przeprowadzono analizę otrzymanych danych, takich jak rozkład naprężeń, odkształceń, wartości granicznej funkcji zniszczenia według Cockrofta-Lathama oraz zmiany wartości siły kształtującej. Zaobserwowano, że zwiększanie wartości kąta rozwarcia klina powoduje duży wzrost sił względem zestawu symetrycznego.

EN

The paper presents the results of numerical tests of the asymmetric cross-wedge rolling process. The computer simulation was performed using the Simufact.Forming 2021 program. Numerical analysis of three cases of cross-wedge rolling was carried out using three sets of tools with different geometry. A rod with a diameter of Ø40 mm and a length of 92 mm made of C45 steel was used as the charge. On the basis of the computer simulation, the received data, such as the distribution of stresses, strains, the limit value of the failure function according to CockroftLatham and changes in the value of the shaping force, were analyzed. It was observed that increasing the value of the wedge opening angle causes a large increase in forces relative to the symmetrical set.

20

Microstructure-related properties of explosively welded multi-layer Ti/Al composites after rolling and annealing

Solecka Monika, Mróz Sebastian, Petrzak Paweł, Mania Izabela, Szota Piotr, Stefanik Andrzej, Garstka Tomasz, Paul Henryk

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e39, 2023

EN

The processes of rolling and annealing of explosively welded multi-layered plates significantly affect the functional properties of the composite. In current research, fifteen-layered composite plates were fabricated using a single-shot explosive welding technique. The composites were then rolled up to 72% to reduce layer thickness, followed by annealing at 625 °C for varying times up to 100 h. Microstructure evolution and chemical composition changes were investigated using scanning electron microscopy equipped with energy-dispersive spectroscopy. The mechanical properties of the composite were evaluated by tensile testing, while the strengths of individual layers near the interface were evaluated by micro-hardness measurements. After explosive welding, the wavy interfaces were always formed between the top layers of the composite and the wave parameters decreasing as the bottom layers approach. Due to the rolling process, the thickness of Ti and Al layers decreases, and the waviness of top interfaces disappeared. Simultaneously, the necking and fracture of some Ti layers were observed. During annealing, the thickness of layers with chemical composition corresponding to the Al3Ti phase increased with annealing time. A study of growth kinetic shows that growth is controlled by chemical reaction and diffusion. The results of micro-hardness tests showed that after annealing, a fourfold increase of hardness can be observed in the reaction layers in relation to the Ti, while in relation to Al, the increase of hardness is even 15 times greater.