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1
Content available remote Modernisation of the drop forging process on the example of forming a bracket forging
Pater Zbigniew
Mechanik
|
2024
|
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.
2
Content available Numerical Modelling of a Rotary Compression Test on a Cylindrical Specimen
Pater Zbigniew
Advances in Science and Technology. Research Journal
|
2024
|
Vol. 18, no 4
23--32
EN
This paper reviews studies on the modelling of the Mannesmann effect, which leads to the formation of an axial crack in parts formed by cross and skew rolling. This effect also occurs in the rotational compression (RC) test of a cylindrical specimen, which is used to determine the critical damage value. RC tests were carried out under laboratory conditions at the Lublin University of Technology on C45 steel specimens formed at 950°C. Based on the tests, the crack propagation was presented as a function of the progress of rotational compression, measured by the length of the deformation path. The RC tests were numerically modelled in Forge® using four ductile fracture criteria. The effectiveness of the Mannesmann effect modelling was evaluated by comparing the numerically predicted cracks with the experimentally determined ones. In addition, the influence of an occurring axial crack on the stress state in the forming specimen was analysed.
3
Content available remote Application of the cross-wedge rolling process to the manufacture of preforms for elongated forgings
Pater Zbigniew
Mechanik
|
2023
|
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.
4
Content available Prediction of Waviness Values in Skew Rolling Using Machine Learning Methods
Lis Konrad, Pater Zbigniew, Tomczak Janusz, Bulzak Tomasz Adam, Kusiak Tomasz
Advances in Science and Technology. Research Journal
|
2023
|
Vol. 17, no 5
350--359
EN
Skew rolling with three rolls is used for producing axisymmetric parts. In this method, the tools are spaced every 120° on the circumference of the workpiece. They are also set askew relative to the rolling axis. Cross sectional reduction is made effective by moving the tapered rolls closer to or away from the center line of the workpiece. Experiments were conducted with variable initial conditions of the rolling process to examine surface topography of rolled parts. Obtained experimental results were then analyzed using machine learning methods in order to determine the most effective regression model with the highest coefficient of determination R2 for waviness prediction.
5
Content available Multi-Variant Analysis of the Cross Wedge Rolling Process for Producing Railcar Axles
Pater Zbigniew, Tomczak Janusz, Bulzak Tomasz Adam
Advances in Science and Technology. Research Journal
|
2023
|
Vol. 17, no 5
208--219
EN
This study investigates the cross wedge rolling (CWR) process for manufacturing a rail axle in a scale of 1:6. Three cases of the rolling process are modelled numerically: standard rolling, wasteless rolling and rolling from a preform. The rolling cases under analysis are compared in terms of material and energy consumption, forming loads as well as propensity to internal and external defect formation. Using the Cockcroft-Latham criterion and the limits of this criterion determined by the rotary compression test, an assessment was made of the propensity of the material to fracture during the rolling processes analysed. Based on numerical results, standard CWR is selected for experimental verification. Obtained experimental results confirm that CWR is an effective method for producing railcar axles that are free from both internal and external defects. The experimental and numerical results obtained confirm that cross wedge rolling technology can be successfully used under industrial conditions for the production of long axles or shafts.
6
Content available Determination of Critical Damage Function Values of CW008A Copper and S355 Steel in Tensile and Torsion Tests
Walczuk-Gągała Patrycja, Pater Zbigniew, Wójcik Łukasz, Lis Konrad
Advances in Science and Technology. Research Journal
|
2023
|
Vol. 17, no 2
173--180
EN
The article describes the problem of material fracture in metal forming processes. It describes and compares the values of damage functions obtained in classical tensile and torsion tests of two materials, i.e. CW008A copper and S355 steel under cold forming conditions. The presented research methodology includes experimental tests and numerical simulation carried out using Simufact.Forming v.15 software. The damage values were analysed according to various criteria, including the growth and coalescence of micro cracks (Rice&Tracey, Oyane, Argon), the initiation and development of ductile cracking in forming processes (Freudenthal, Cockroft-Latham, Brozzo, Oh) and using extended phenomenological models based on the history of stress triaxiality (Ayada) or the mean and equivalent stress (Zhan). The conducted tests showed that the values of the damage function depend on: the calibration test, the material grade and the geometry of the specimen.
7
Content available A Comparison of Two-Roll and Three-Roll Cross Wedge Rolling Processes
Pater Zbigniew
Advances in Science and Technology. Research Journal
|
2023
|
Vol. 17, no 1
252--266
EN
Cross wedge rolling (CWR) is used for producing stepped axles and shafts as well as die forging preforms. In current industrial practice, CWR conducted with two tools is predominantly used, with the wedges mounted on rolls or flat tool plates. However, CWR can also be performed with the use of three wedge rolls. This paper begins with a review of previous studies on CWR conducted with the use of three rolls. After that, numerical simulations of two- and three-roll CWR processes for the same shaft are described. Obtained numerical results are then used to compare the two processes in terms of material flow kinematics, material temperature, stresses and strains, failure modes, as well as load and energy parameters. Finally, the Conclusions section presents the advantages of three-roll cross wedge rolling, providing a good starting point for further research on this promising forming method.
8
Content available remote Numerical simulation of a cross-wedge rolling process in a mill with horizontally stacked rolls
Pater Zbigniew, Bulzak Tomasz, Tomczak Janusz
Mechanik
|
2022
|
R. 95, nr 5-6
54--58
EN
This paper presents simulations of the cross wedge rolling (CWR) process of a railway axle. It is assumed that the rolls are arranged horizontally, which should facilitate both the loading of the charge and the unloading of the rolled product. Simulations were performed in the Forge® programme, based on the finite element method (FEM). It was found that the adopted rolling scheme and design of wedge tools ensures the achievement of a correctly formed railway axle, free of internal (cracks) and external defects (overlapping, bending). The force parameters determined in the simulations can be used in the design works of the rolling mill guaranteeing the railway axle forming process.
PL
Przedstawiono symulacje procesu walcowania poprzeczno-klinowego (WPK) osi kolejowej. Przyjęto, że walce ułożone są poziomo, co powinno ułatwić zarówno załadowanie wsadu, jak i wyładowanie odwalcowanego wyrobu. Symulacje wykonano w programie Forge®, bazującym na metodzie elementów skończonych (MES). Stwierdzono, że przyjęty schemat walcowania oraz konstrukcja narzędzi klinowych zapewniają uzyskanie prawidłowo ukształtowanej osi kolejowej, wolnej od wad wewnętrznych (pęknięć) i zewnętrznych (zawalcowań, wygięć). Określone w symulacjach parametry siłowe można wykorzystać w pracach projektowych walcarki zabezpieczającej proces kształtowania osi kolejowych.
9
Content available remote Numerical and experimental study on forming preforms in a CNC skew rolling mill
Pater Zbigniew, Tomczak Janusz, Bulzak Tomasz, Walczuk-Gągała Patrycja
Archives of Civil and Mechanical Engineering
|
2022
|
Vol. 22, no. 1
art. no. e54, 2022
EN
This paper relates to a study on the formation of elongated preforms in a CNC skew rolling mill. First, a numerical analysis was performed to investigate forming processes for three different parts: a scraper, a connecting rod, and a hook. The shapes and dimensions of preforms were designed, and rolling and closed-died forging processes for producing these parts were simulated numerically. Distributions of temperature, effective strain and damage function were determined for rolled preforms. Loads and torques in the rolling process were measured. It was found that the forming process of preforms performed in a CNC skew rolling mill was characterized by relatively low force parameters in relation to the dimensions of formed parts. Numerical simulations of the forging process showed that all forged parts had the required shape, which indicates that the preforms were designed correctly. Following the numerical analysis, experiments were performed in which the preforms were rolled under laboratory conditions (in a scale of 1:2). Experimental results demonstrated that the rolled parts had no internal defects (cracks) and were characterized by high dimensional accuracy.
10
Content available Study of Cross Wedge Rolling Process of BA3002-Type Railway Axle
Pater Zbigniew
Advances in Science and Technology. Research Journal
|
2022
|
Vol. 16, no 2
225--231
EN
The paper deals with the concept of solid railway axle rolling using tools (rolls) in which the forming zones of individual workpiece steps are separated. Two types of tools were analysed, which were characterised by flat (typical solution) and convex (novel solution) forming surfaces of the wedge. Using the software Forge® NxT, simulations were performed of the rolling processes of the rail axle. Distributions of temperature, damage function, effective strain as well as force and torque courses were analysed. The results showed that it is possible to produce solid railway axles using the CWR method and confirmed the use of tools with a convex forming surface.
11
Content available remote Design and technological capabilities of a CNC skew rolling mill
Tomczak Janusz, Pater Zbigniew, Bulzak Tomasz, Lis Konrad, Kusiak Tomasz, Sumorek Andrzej, Buczaj Marcin
Archives of Civil and Mechanical Engineering
|
2021
|
Vol. 21, no. 2
524--540
EN
Results of a study investigating a skew rolling process for elongated axisymmetric parts are presented. Despite the fact that the skew rolling technique for producing such parts was developed and implemented in the mid-twentieth century, there are no studies on this problem. The first part of this paper presents the results of FEM modelling of skew rolling stepped axles and shafts (solid and hollow). The FEM analysis was performed using the MSC Simufact Forming software. The numerical simulation involved the determination of metal flow patterns, the analysis of thermal parameters of the material during rolling, and the prediction of cracking by the Cockcroft-Latham ductile fracture criterion. Force parameters of rolling solid and hollow parts were also determined. The aim of the FEM analysis was to determine initial design assumptions and parameters for the development of the skew rolling mill. Later on in the paper, a design solution of a CNC skew rolling mill for rolling parts based on their envelope profile is proposed. FEM strength test results of a mill stand, obtained with MSC. NASTRAN, are presented. Finally, the performance test results of the constructed rolling mill are presented. The experiments involved rolling real stepped shafts that were modelled numerically. Obtained results show that the proposed skew rolling method has considerable potential. The designed and constructed rolling mill can be used to perform the rolling process according to the proposed method, with the tool and material kinematics being controlled based on the set parameters of a workpiece envelope.
12
Content available Conception of Hollow Axles Forming by Skew Rolling with Moving Mandrel
Pater Zbigniew, Walczuk-Gągała Patrycja
Advances in Science and Technology. Research Journal
|
2021
|
Vol. 15, no 3
146--154
EN
The article presents a conception of manufacturing a hollow axle using three skewed rolls moving at the same rotating speed, axially moving chuck and a moving mandrel. The outer shape of the axle is obtained as a result of combining the radial feed of the rolls with axial feed of the chuck. The hole in the axle, however, is obtained as a result of the mandrel acting on the workpiece while moving along with it. In order to assess the correctness of the presented concept of forming, a numerical simulation was performed in Simufact.Forming commercial software. The results of the simulation confirmed that the applied method allows one to manufacture large-size hollow axles. Moreover, information on force parameters of the forming process, which can be used for designing an industrial rolling mill was obtained.
13
Content available remote Numerical analysis of the cross-wedge rolling process of a railway axle
Pater Zbigniew
Mechanik
|
2020
|
R. 93, nr 2
18--21
EN
The article presents an innovative method of manufacturing railway axle using two wedge rolls. The novelty of the solution consists in the simultaneous forming of axle by three pairs of wedges, which allows to significantly shorten the length of tools, leading to a reduction of the diameter of the rolls to an acceptable value. The correctness of the proposed solution was verified by means of numerical simulation. The shape progression of the formed axle, the effective strain, temperature and damage function distributions are presented. It is also shown how the force and torque on the rollers changes during rolling process.
PL
W artykule przedstawiono innowacyjną metodę wytwarzania osi kolejowych za pomocą dwóch walców klinowych. Nowość rozwiązania polega na jednoczesnym kształtowaniu osi przez trzy pary klinów, co pozwala na znaczne skrócenie długości narzędzi, prowadzące do zmniejszenia średnicy walców do akceptowalnej wartości. Poprawność zaproponowanego rozwiązania sprawdzono na drodze symulacji numerycznej. Przedstawiono geometrię ukształtowanej osi oraz rozkłady intensywności odkształcenia, temperatury i funkcji zniszczenia. Pokazano również, jak w trakcie kształtowania zmieniają się siła i moment obrotowy na walcach.
14
Content available remote Numerical analysis of the cross rolling process of a hollow railway axle
Pater Zbigniew
Mechanik
|
2020
|
R. 93, nr 8-9
48--52
EN
Presented is an innovative method of manufacturing hollow railway axle using three rolls. The novelty of the solution consists of the simultaneous forming of the hollow axle by three tools, which allows to quickly remove ovalisation of the cross-section of the workpiece. The correctness of the proposed solution was verified using numerical simulation. The influence of the rollers’ rotational speed on the forming process was analysed. The shape progression of the formed hollow axle, the effective strain, temperature and damage function distributions are presented. It is also shown how the force and torque on the rollers change during the rolling process.
PL
Przedstawiono innowacyjną metodę wytwarzania osi kolejowych z użyciem trzech walców. Nowość rozwiązania polega na jednoczesnym kształtowaniu drążonej osi przez trzy narzędzia, co pozwala na szybkie usunięcie owalizacji przekroju poprzecznego obrabianego elementu. Proponowane rozwiązanie sprawdzono w symulacji numerycznej. Przeanalizowano wpływ prędkości obrotowej walców na przebieg kształtowania. Przedstawiono geometrię ukształtowanej drążonej osi, rozkłady intensywności odkształcenia, temperatury oraz funkcji zniszczenia. Pokazano również, jak w trakcie kształtowania zmieniają się siła i moment obrotowy na walcach.
15
Walcowanie śrubowo – klinowe
Bulzak Tomasz, Tomczak Janusz, Pater Zbigniew
Hutnik, Wiadomości Hutnicze
|
2020
|
Vol. 87, nr 1-2
22--24
PL
Walcowanie śrubowo-klinowe (WŚK) jest technologią stosowaną w produkcji wyrobów osiowosymetrycznych. W procesie tym wykorzystuje się narzędzia klinowe, które wcinają się w kształtowany materiał wprawiając go w ruch obrotowy. Rozszerzający się klin powoduje stopniowe redukowanie średnicy wsadu do średnicy wyrobu finalnego. Klin do walcowania śrubowo-klinowego jest nawinięty wzdłuż linii śrubowej na powierzchni walca. Rozwiązanie to pozwala kształtować wyroby osiowosymetryczne w sposób ciągły z jednego odcinka pręta. Proces charakteryzuje się bardzo dużą wydajnością i znajduje największe zastosowanie w produkcji stalowych kul. W artykule opisano konstrukcję walcarek stosowanych w procesie walcowania śrubowo-klinowego. Przestawiono również na przykładach możliwości technologii walcowania śrubowo-klinowego. Opisano proces walcowania kul stosowanych na mielniki do młynów kulowych. Przedstawiono proces walcowania prętów z wyrobów o przekroju niesymetrycznym takich jak główka szyny kolejowej. Pokazano również możliwości walcowania odkuwek osiowosymetrycznych na przykładzie walcowania sworzni kulistych.
EN
Helical wedge rolling (HWR) is a technology used for manufacturing axially-symmetric products. Wedge tools used in this process cut into the formed material and, as a result, set it in rotational motion. The widening wedge causes the diameter of the billet to gradually decrease. The wedge used in the helical wedge rolling process is wound along the helix on the surface of the roll. This method allows one to manufacture axially symmetric products uninterruptedly from one section of a rod. The process is highly effective and is most widely applied in production of steel balls. The design of rolling mills used in the helical wedge rolling process was described. The article presents examples of the possibilities of helical wedge rolling. The process of rolling balls used as milling elements in ball mills was described. The process of rolling rods from products with asymmetric cross-section, such rail heads was presented. Moreover, the possibility of rolling axially symmetric forgings was presented on the example of ball pin.
16
Content available remote Forming of rail car axles in a CNC skew rolling mill
Pater Zbigniew, Tomczak Janusz, Lis Konrad, Shu Xuedao
Archives of Civil and Mechanical Engineering
|
2020
|
Vol. 20, no. 3
78--90
EN
This study relates to an innovative method for forming rail car axles by skew rolling in a CNC 3-roll mill. The rolling mill was constructed at the Lublin University of Technology. The use of this machine makes it possible to produce elongated axisymmetric parts that are up to 55 mm in diameter and up to 1000 mm in length. Experimental rolling tests are performed (in 1:5 scale) using this machine. Two types of axles are analysed: one manufactured in accordance with North American standards (AAR Class E) and one manufactured in compliance with European standards (BA302). Diameters of produced axles have a dimensional accuracy of ± 0.4 mm. Produced axles are free from internal cracks, and their surface defects (shallow helical grooves) can easily be removed by machining. The major shortcoming of the proposed method is the presence of chucking allowance. To eliminate this allowance, it is proposed that the forming process should be performed in two operations: rolling extrusion and skew rolling. Results of a numerical analysis were performed using the Simufact.Forming program confirms that rail car axles can be formed by the proposed method.
17
Content available Numerical Analysis of the Cross-Wedge of a Hollow Rail Axle
Pater Zbigniew, Lis Konrad, Walczuk-Gągała Patrycja
Advances in Science and Technology. Research Journal
|
2020
|
Vol. 14, no 1
145--153
EN
The article presents an innovative method of manufacturing hollow rail axles using three combined wedge rolls. The proposed solution was evaluated using numerical simulation. Two cases of forming, differing in the wall thickness of the billet, were analysed. The geometry of the formed axles, distributions of the effective strain, temperature and damage function were presented. Moreover, the changes to the forces and torques acting on each roll were presented.
18
Content available Determination of the Value of the Damage Function in 1050A Aluminium Alloy
Walczuk-Gągała Patrycja, Pater Zbigniew, Wójcik Łukasz
Advances in Science and Technology. Research Journal
|
2020
|
Vol. 14, no 2
49--55
EN
The article presents the problem of material cracking in metal forming processes. The authors describe and compare the values of damage obtained in classic tensile and compression tests as well as rotational compression of 1050A aluminium alloy in cold working conditions. The presented research methodology contains experimental tests as well as a numerical simulation conducted in Simufact.Forming v.15. An analysis of the damage values was calculated according to the normalised Cockcroft-Latham criterion. The research conducted showed that the damage value in the rotational compression test is greater than the values obtained by the means of other tests.
19
Analiza numeryczna walcowania skośnego stopniowanych wałków ze stopów metali nieżelaznych
Lis Konrad, Pater Zbigniew
Rudy i Metale Nieżelazne Recykling
|
2019
|
R. 64, nr 1
21--25
PL
W artykule opisano przykłady kształtowania stopniowanych wałków ze stopu tytanu w gatunku TiAl6V4 oraz stopu magnezu w gatunku AZ31 metodą walcowania skośnego. Stopniowane wałki kształtowano za pomocą trzech rolek stożkowych obracających się z jednakową prędkością w tą samą stronę, które miały możliwość jednoczesnego zsuwania lub rozsuwania się w celu redukcji przekroju poprzecznego odkuwki. Na podstawie wykonanych obliczeń numerycznych uzyskano: rozkłady intensywności odkształcenia, temperatury, kryterium zniszczenia według Cockrofta-Lathama oraz rozkłady sił i momentów walcowania.
EN
he paper describes a skew rolling process for production of stepped shafts made of titanium alloy TiAl6V4 and AZ31 magnesium alloy. The parts are formed by three tapered rolls that are rotated at identical speed in the same direction. The rolls can simultaneously converge or diverge in order to reduce the cross section of the workpiece. The numerical analysis provided information about the distributions of effective strains, temperatures, Cockroft-Latham damage criterion as well as the variations in the loads and torques.
20
Walcowanie śrubowe kul na gorąco i ciepło – analiza porównawcza
Bulzak Tomasz, Tomczak Janusz, Pater Zbigniew
Hutnik, Wiadomości Hutnicze
|
2019
|
Vol. 86, nr 10
305--308
PL
Artykuł przedstawia rozważania dotyczące procesu walcowania śrubowego kul łożyskowych. Analiza teoretyczna oparta jest na wynikach symulacji numerycznych. Symulacje numeryczne przeprowadzono w oprogramowaniu Forge NxT. Przeprowadzone symulacje dotyczyły walcowania kul ∅42 mm ze stali 100Cr6. W zaplanowanych badaniach dokonano analizy wpływu temperatury walcowania. Przenalizowano stan odkształcenia podczas walcowania w różnych temperaturach. Wyznaczono parametry siłowe procesu walcowania w niższych temperaturach. Określono zużycie energii potrzebnej do nagrzewania wsadu przy walcowaniu na ciepło oraz gorąco. Przeprowadzono również analizę porównawczą zużycia walców śrubowych w zależności od temperatury walcowania. Zwrócono uwagę na jakość kształtowanych elementów oraz utrudnienia wynikające z walcowania w niższych temperaturach.
EN
The article presents considerations regarding the process of helical rolling of balls bearings. Theoretical analysis is based on the results of numerical simulations. Numerical simulations were carried out in the Forge NxT software. The simulations carried out concerned rolling of ∅42 mm balls made of 100Cr6 grade steel. The planned studies have analyzed the influence of the rolling temperature. The state of strain during rolling at different temperatures was carried out. The force parameters of the rolling process at lower temperatures were determined. The energy consumption needed to heat the billet during warm and hot rolling was determined. Comparative analysis of the wear of helical rollers was also carried out depending on the rolling temperature. Attention was paid to the quality of balls elements and difficulties resulting from rolling at lower temperatures.
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