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1
Content available remote Niekonwencjonalne metody kształtowania plastycznego
PL
W artykule przedstawiono koncepcje czterech niekonwencjonalnych metod przeróbki plastycznej: kucia z oscylacyjnym skręcaniem, kucia z poprzecznym ruchem stempla, walcowania z poprzecznym ruchem walców oraz kucia segmentowego. Metody te umożliwiają wytwarzanie wyrobów o nietypowych właściwościach użytkowych oraz istotne zmniejszenie wymaganych sił nacisku narzędzi kształtujących. Wdrożenie zaprezentowanych sposobów kształtowania plastycznego pozwoliłoby na rozszerzenie asortymentu produkcji wielu przedsiębiorstw działających w branży metalowej.
EN
Concepts of four unconventional metal forming methods: compression with oscillatory torsion, compression with transverse punch motion, rolling with transverse rolls motion and incremental forging are presented in the paper. The methods enable manufacturing products with unique functional properties and significant reduction of the required press load. Industrial implementation of the presented metal forming techniques would allow to extend the assortment of many metal parts manufacturers.
PL
Przedstawiono innowacyjny sposób wytwarzania matryc kuziennych, wdrażany w kuźni przemysłowej. Robocze powierzchnie rdzenia matrycy wykonanego ze stali konstrukcyjnej napawano materiałami odpornymi na destrukcyjne oddziaływanie procesu technologicznego kucia. Opracowano i wdrożono specjalny program komputerowy dla robota spawalniczego, który zapewnia precyzję napawania matrycy. Wprowadzony innowacyjny sposób wytwarzania matryc kuźniczych w pełni zapewnia wymaganą jakość odkuwek przy zachowaniu stałych parametrów matrycy w okresie eksploatacji.
EN
An innovative method of producing forging dies, implemented in an industrial forge, was presented. The working surfaces of the die core made of structural steel were padded with materials resistant to the destructive impact of the technological forging process. A special computer program has been developed and implemented for the welding robot that ensures the precision of the matrix welding. The introduced innovative method of producing forging dies fully ensures the required quality of forgings while maintaining constant parameters of the matrix during the operation period.
PL
Przedstawiono parametry procesu technologicznego wytwarzania matryc kuziennych. Przeanalizowano wpływ czynników oddziaływujących bezpośrednio na trwałość matryc. Scharakteryzowano kryteria doboru materiałów na podłoże matrycy (rdzeń) i napoinę w aspekcie dostępności rynkowej w celu wykonania badań weryfikujących ich parametry technologiczne. W oparciu o teorię podobieństwa określono wartości strumieni cieplnych zapewniających stabilizację temperatury matrycy podczas procesu napawania.
EN
Parameters of the technological process of manufacturing forging closed - dies are presented. The influence of factors directly affecting the durability of the closed - dies was analyzed. The criteria for the selection of materials for the closed - dies substrate (core) and the padding weld were characterized in terms of market availability, in order to perform tests verifying their technological parameters. Based on the theory of similarity, the values of thermal fluxes ensuring the stabilization of the closed - dies temperature during the padding process were determined.
EN
The quaternary Mg–9Li–2Al–0.5Sc alloy (in wt%) was prepared from pure components. After homogenization, the alloy was subjected to severe plastic deformation by KoBo extrusion and cyclic forging leading to grain refinement in the range of 0.5–2 µm of hexagonal close-packed (HCP) α phase. Deformed alloys showed high ultimate tensile strength near 200 MPa and good elongation in the range 30–40% at room temperature (RT). Large elongations close to 200% were obtained during the tensile test at a temperature of 200 °C. Deformed samples showed the presence of multiple voids confirming grain boundary sliding mechanism of deformation. Twins on {101-2} planes were identified using electron backscatter diffraction analysis, being in a good agreement with the earlier observation of Mg–Li and Mg–Sc alloys. Intermetallic phases such as cubic MgSc were identified in deformed alloys mostly within HCP α phase, whereas HCP MgSc2 particles were observed within body-centered cubic (BCC) β phase. Intermetallic phases were responsible for RT strengthening of alloys and slightly lower tensile elongation during superplastic deformation. Formation of the HCP α phase was observed within the BCC β phase in tensile deformed alloys. Atomic-level nucleation of HCP phase within the β phase was identified by the use of high-resolution transmission electron microscopy technique.
EN
The effect of multi-pass multi-directional forging (MDF) on the microstructure and mechanical properties of Zn–22Al–xSi (X = 4 and 8 wt. %) alloy, also known as SiP/ZA22 composite, was investigated. MDF process was applied at 100 °C for one, three, and five passes with the strain of 0.47 per pass. According to the results, MDF refined and homogenized the composites microstructure so that the average size of primary Si (SiP) particles reduced from 25.0 µm and 30.4 µm in as-cast ZA22-4Si and ZA22-8Si composites to about 6.2 µm and 7.3 µm in five-pass MDFed condition, respectively, and their distribution shifted to the smaller size range. Mechanical properties tests revealed that multi-pass MDF has softened the investigated composite. For instance, the hardness, tensile strength, and shear strength of ZA22-4Si composite reduced from 83 HV, 280 MPa, and 165 MPa in as-cast condition to about 58 HV, 160 MPa, and 118 MPa in the five-pass MDFed sample, respectively. This is while its fracture strain increased from 15% to about 40% with the strain rate of 1.2 × 10–3 s−1.
EN
The combined effect of extrusion and multi-directional forging (MDF) was investigated on microstructure and mechanical properties of aluminum-based composite with 10, 15, and 20 wt% Mg2Si. In the casted Al–Mg2Si composites, the primary and eutectic Mg2Si particles are generally coarse which lead to decreasing their mechanical properties and formability. Extrusion process was utilized to overcome this shortcoming by breakage of the eutectic structure, reduction of Mg2Si size, and the decrease of casting defects. Then, MDF process was applied up to failure on the extruded composites at room temperature. It led to the morphological modification of primary and eutectic Mg2Si phases and the reduction of their size. It was found that the MDF process resulted in a considerable improvement in hardness and shear strength of materials. This may be related to the reduction in the average size of Mg2Si particles with their uniform distribution. In addition, ultimate shear strength is, respectively, increased from 94, 99, and 81 MPa to 119, 116, and 117 MPa for the 10, 15, and 20 wt% Mg2Si aluminum composites after the final pass of MDF. Meanwhile, the normal displacement of composites is reduced at initial passes and increased by the addition of more pass numbers.
PL
Artykuł prezentuje wyniki modelowania numerycznego wieloetapowego procesu kucia haka holowniczego prowadzonego w matrycach otwartych na gorąco na linii kuźniczej wykorzystującej młoty parowo-powietrzne. Celem prowadzonych badań jest analiza przemysłowego procesu wytwarzania pozwalająca przede wszystkim na określenie parametrów/ wielkości, które trudno wyznaczyć bezpośrednio w procesie lub w sposób doświadczalny, a dla których wyznaczone i następnie wprowadzone w modelowaniu ich zmiany mogą wpłynąć na poprawę aktualnie realizowanej technologii.
EN
The paper presents an innovative precision forging process, highlighting the use of advanced simulation of net forging process in multiple-tool die set with consideration of counter-pressure and interaction of components so as to control speed and displacement of metal flow. In addition to the use of finite element method in optimization of process conditions, damage criteria have been formulated to investigate the effect on plasticity and tendency of formation of defects and define process conditions which contribute to cracking occurrence in warm forging of magnesium alloy AZ61. Both forged samples and numerical simulation prediction indicate minimization of cracking hazard in lower work-temperature range at relatively high strain rate by employing counter-pressure imposing hydrostatic component into state of stress.
9
Content available remote Recent development trends in metal forming
EN
Major, recent developmental trends in the field of metal forming are presented in the paper both from experimental and numerical point of view. First, progress made in metal forming processes such as: rolling of long flat products, cross wedge rolling, open die forging, die forging, extrusion, drawing, and stamping are addressed. Then, the study provides infor-mation on the current trends in the application of numerical modeling in the field of metal forming. Presented discussion of the particular issues, is confronted with the authors' own, recently elaborated, solutions.
EN
The quality evaluation shall be the primary objective of acceptance testing of forgings for crankshafts. This paper presents technological issues concerning the production of crankshafts. It also characterizes and presents the scope of application of free forging and discusses the properties of steel used in crankshafts. The research part of the paper includes the analysis of selected test methods for determining the quality of forgings intended for crankshafts.
PL
Duże zapotrzebowanie na odkuwki w postaci pierścieni dla różnych gałęzi przemysłu wymaga stosowania nowoczesnych stali martenzytycznych o właściwościach mechanicznych dostosowanych do konkretnego zastosowania. Aby sprostać wymaganiom rynku, powstała koncepcja projektu niskoodpadowej technologii kształtowania wielkogabarytowych pierścieni ze stali X20Cr13 i X10CrMoVNb9-1 o profilowanych pobocznicach. Liderem projektu jest firma Zarmen FPA. Jednym z etapów tego projektu jest opracowanie technologii obróbki cieplnej pierścieni. Wykonano badania mikrostruktury i właściwości mechanicznych (wg norm PN-EN ISO 6892-1:2016-09, PN-EN ISO 148-1:2017-02 i PN-EN ISO 6507-1:2007) na próbkach pobranych z odkuwek kutych swobodnie przy temperaturze 1110±20°C z redukcją wysokości materiału wsadowego 50% oraz obrobionych cieplnie w 2 wariantach: hartowanie stali X20Cr13 z temperatury 1020±10°C w oleju oraz odpuszczanie przy temperaturze 600°C i 700°C, hartowanie stali X10CrMoVNb9-1 z temperatury 1050±10°C w oleju oraz odpuszczanie przy temperaturze 650°C i 700°C. Materiałem wsadowym były wałki ϕ40x60 mm. Wykonano też badania porównawcze na próbkach pobranych z wałków w stanie dostawy hutniczej i poddanych obróbce cieplnej w tych samych warunkach co odkuwki. Wskaźniki Rp0,2 i Rm, zgodne z założeniami, otrzymano dla obu stali po odpuszczaniu próbek pobranych z odkuwek przy temperaturze 700°C, wynoszące odpowiednio: 660 MPa i 844 MPa dla stali X20Cr13 oraz 764 MPa i 893 MPa dla stali X10CrMoVNb9-1. Wydłużenie próbek z obu stali wyniosło 21%, a praca łamania KV2: 25 J dla stali X20Cr13 i 38 J dla stali X10CrMoVNb9-1. Planowana jest weryfikacja właściwości mechanicznych uzyskanych na próbkach pobranych z kutych wałków oraz z eksperymentalnie walcowanych pierścieni.
EN
The large demand for forgings in the form of rings for various branches of industry requires the application of modern martensitic steels with mechanical properties adapted to the specific application. To meet the requirements of the market, the first concept of low-waste forming technology for large-size rings made of X20Cr13 and X10CrMoVNb9-1 steel, with profiled side surfaces, was created. The leader of the project is Zarmen FPA. One of the stages of this project is the development of ring heat treatment technology. Tests of microstructure and mechanical properties (according to standards PN-EN ISO 68921:2016-09, PN-EN ISO 148-1:2017-02 and PN-EN ISO 6507-1:2007) were performed on samples collected from flat-die forgings at temperature 1110±20°C with 50% height reduction of the stock material and heat treatment in 2 variants: hardening of X20Cr13 steel from temperature 1020±10°C in oil and tempering at temperature 600°C and 700°C, hardening of X10CrMoVNb9-1 steel from temperature 1050±10°C in oil and tempering at temperature 650°C and 700°C. The stock material was ϕ40x60 mm shafts. Comparative tests were also performed on samples collected from shafts in the state as delivered from the mill and subjected to heat treatment under the same conditions as forgings. Indicators Rp0.2 and Rm, according to assumptions, were obtained for both steels after tempering of samples collected from forgings at temperature 700°C, and were equal to, respectively: 660 MPa and 844 MPa for X20Cr13 steel and 764 MPa and 893 MPa for X10CrMoVNb9-1 steel. Elongation of samples for both steels was 21%, and energy absorbed during fracture KV2: 25 J for X20Cr13 steel and 38 J for X10CrMoVNb9-1 steel. It is planned to verify mechanical properties obtained in samples collected from forged shafts and from experimentally rolled rings.
EN
In this paper, the analysis of the three-dimensional strain state for the hot cogging process of a steel tool with the application of the finite element method is presented. The results of work connected with the simulation of metal flow scheme, and fields of stress, strain and temperature in the material deformation process in the hot forging conditions are presented. The distribution of the effective strain, the effective stress, mean stresses and temperature on the surface of forging cross sections are determined. The numerical analysis was performed with the application of the programme DEFORM-3D. The theoretical results are subjected to experimental verification.
PL
W artykule zaprezentowano możliwości zastosowania metody replikowania geometrii narzędzia kształtującego wyrób w procesie kucia dokładanego na gorąco do kontroli cech geometrycznych z wykorzystaniem techniki skanowania laserowego 3D. Spośród kilkunastu mas o rożnych właściwościach i przeznaczeniu, badaniom poddano dwie masy do replikowania o zbliżonych parametrach, którymi wypełniono matrycę kuźniczą o głębokim -wykroju roboczym stosowaną w procesu wyciskania współbieżnego. Uzyskane wyniki wykazały, że w oparciu o wybrane parametry charakteryzujące masy replikacyjne oraz własne badania możliwy jest dobór optymalnej masy dla pomiarów wykonywanych metodą skanowania 3D ze względu na najlepsze odwzorowanie warstwy wierzchniej i zminimalizowanie deformacji pojawiającej się podczas usuwania replik z mierzonych wykrojów roboczych matryc. Zaproponowane podejście wykorzystujące pomiar w technice skanowania 3D mas replikacyjnych powierzchni narzędzi umożliwia przeprowadzanie badań nieniszczących dla pełnych roboczych powierzchni matryc kuźniczych o głębokich wykrojach i -wspomaganie procesu podejmowania decyzji o ich dalszej eksploatacji poprzez miarodajne określenie ich zużycia.
EN
The article presents the possibilities of using the method of replicating the geometry of the tool shaping the product in the hot forging process for the control of geometric features using 3D laser scanning. Out of a dozen or so masses with different properties and purpose, two masses for replication with similar parameters were tested, which were filled with a forging die with a deep working cavity used in the process of forward extrusion. The obtained results showed that on the basis of the selected parameters characterizing replication masses and own test s, it is possible to select the optimal mass for 3D scanning measurements due to the best mapping of the surface layer and the minimization of the deformations occurring when removing the replicas from the measured working cavities of the dies. The proposed approach using measurement in the 3D scanning technique of replicate masses of tool surfaces enables to perform non-destructive testing of full working surfaces of forging dies with deep cavities and to support decision making about their further exploitation by the reliable determination of their wear.
EN
The paper presents the results of low cycle fatigue studies of WCLV tool steel aimed at determining the diagrams of low cycle fatigue and verifying them based on the analysis of durability of the selected forging tool. Based on the macro- and microstructural tests as well as numerical modelling of industrial forging processes, the conditions for the implementation of laboratory fatigue tests were determined. The samples underwent periodical uniaxial loading (tension–compression conditions) at four levels of amplitude of total strain (0.5; 0.8; 1.0; 2.0%), at three temperatures (20, 300 and 600 °C), based on the macro- and microstructural tests as well as numerical modelling of industrial forging processes. For the determination of the hysteresis loop based on the obtained fatigue results, the Ramberg–Osgood equation was applied. The fatigue diagrams in the bilogarithmic system were approximated by the Manson–Coffin–Basquin equation, and the diagrams of low cycle fatigue in the ɛa–Nf and σa–Nf system were obtained. The results of the laboratory tests concerning the fatigue strength of WCLV tool steel were preliminarily verified based on the analysis of the punch used to forge a lid forging, exhibiting a good agreement. The performed comparative analysis of the results of the fatigue tests and the numerical analysis combined with the studies of the microstructure revealed the possibility of their application in the aspect of forging tools’ durability as well thermo-mechanical fatigue strength.
15
Content available remote Forging of Mg/Al bimetallic handle using explosive welded feedstock
EN
The paper presents the results of investigation into the possibility of employing the forging process to produce aluminium-clad magnesium products. The purpose of the investigation was to develop and implement the technology of Mg/Al bimetal feedstock screw press forging and to compare the corrosion resistance of the product with that of an identical product made of a magnesium alloy. The feedstock was round 22.5 mm-diameter and 160 mm-length Mg/Al bars that had been produced using the explosive welding method. As an example product, a door handle used in helicopter production was selected. For comparison purposes, the door handle was also forged of magnesium alloy AZ31. After the forging process, the both products were subjected to corrosion resistance testing. From the obtained results it was found that the forging of the assumed quality could be made in the process of forging on the screw press, and that the use of the aluminium cladding layer only slightly increased the mass of the finished products, while substantially improving its corrosion resistance.
EN
This article concerns a decision-support system based on artificial neural networks (ANN) enabling analysis and forecasting of the durability of forging tools used in the hot forging process of a cover forging – a sealing element of the driveshaft in road freight vehicles. The process of knowledge acquisition, adopted neural network architecture and parameters of the developed network are presented. In addition, 3 variants of a hybrid layer (gas nitrided layer GN + PVD coating) were applied to the selected tools (punches applied in the 2nd top forging operation): GN/AlCrTiN, GN/AlCrTiSiN, and GN/CrN, in order to improve durability, and the resultant tools were also compared to standard tools (with only gas nitriding) and regenerated tools (after repair welding regeneration). The indispensable knowledge about the durability of selected forging tools (after various surface engineering variants), required for the process of learning, testing and validation for various neural network architectures was obtained from comprehensive, multi-year studies. These studies covered, among other things: operational observation of the forging process, macroscopic analysis combined with scanning of tools’ working surfaces, microhardness measurements, microstructural analysis and numerical modeling of the forging process. The developed machine-learning dataset was a collection of approx. 900 knowledge records. The input (independent) variables were: number of forgings manufactures, pressing forces, temperature on selected tool surfaces, friction path and type of protective layer applied to tool. Meanwhile, output (dependent) variables were: geometrical loss of tool material and percentage share of the four main destructive mechanisms. Obtained results indicate the validity of employing ANN-based IT tools to build decision-support systems for the purpose of analyzing and forecasting the durability of forging tools.
PL
W artykule podjęto temat procesu technologicznego kucia półfabrykatu wałka rozrządu. Scharakteryzowano materiały stosowane na półfabrykaty wałków rozrządu. Określono warunki doboru technologii wytwarzania półfabrykatów. Przedstawiono proces kucia i matrycowania. Dokonano też opisu prac kończących produkcję półfabrykatów wałków rozrządu. Opracowano kartę technologiczną dla procesu kucia.
EN
The article presents technological process of forging blank camshafts. It describes materials used on the camshafts blanks. The paper also sets out the conditions for the selection of manufacturing technology of semi-finished products. It shows the process of forging and stamping. The ending work in the production process of semi-finished products is described. The card for forging process of semi-finished camshafts is developed.
EN
The aim of the study was to conduct dry sliding tests on the designed hypereutectoid steels with the controlled contents increase of carbon, chromium, and manganese. Chromium and manganese were used to balance the changes related to the higher secondary carbides’ precipitation in the chemical composition of the matrix. Samples were investigated by the use of the block on disk friction method under the load of 100 N. The duration of each test was 2000 s with the wear track length approx. 500 m. The samples were investigated in the as-cast state and after hot plastic deformation. Two sets of four samples were prepared from the ingots and plastically deformed material. The heat treated (quenched and tempered) 100Cr6 steel was used as the counter-sample, with a new counter-sample used for each test. The obtained results show a decrease of the average friction coefficient for samples after plastic deformation. The phenomena that influenced this effect the most, observed in the alloy with the higher concentration of alloying elements, were grain boundary net defragmentation of secondary carbides and the elimination of Widmannstaten needles. The main wear mechanisms occurring during the tribological tests were sliding wear and material spalling.
PL
W pracy przedstawiono badania tribologiczne zaprojektowanych stopów nadeutektoidalnych z kontrolowanymi zmiennymi zawartościami węgla, chromu i manganu. Zwiększone zawartości chromu i manganu balansowały zubożenie osnowy w te pierwiastki związane z wydzielaniem większych ilości cementytu drugorzędowego. Stopy te badane były w układzie trącym klocek–pierścień przy obciążeniu 100 N. Czas trwania próby tribologicznej wynosił 2000 s, natomiast droga tarcia 500 m. Stopy te badane były w stanie po odlaniu, jak i po przeróbce plastycznej. Z odlewów i próbek odkształconych wykonano dwa zestawy po cztery próbki tribologiczne. Przeciwpróbkę stanowiła ulepszona cieplnie stal 100Cr6, dla każdej z prób użyto nowych przeciwpróbek. Badania pozwoliły na zaobserwowanie zmniejszenia wartości średniego współczynnika tarcia dla materiałów po przeróbce plastycznej. Największy wpływ na ten efekt miało przerwanie siatki cementytu drugorzędowego na granicach ziarn oraz usunięcie iglastych wydzieleń cementytu Widmannstatena obserwowanych w stopie o wyższym stężeniu pierwiastków stopowych. Głównym mechanizmem zużycia było zużycie ścierne z niewielkim udziałem wykruszania.
PL
W artykule przedstawiono rezultaty badań wpływu oddziaływania podwyższonych temperatur na właściwości warstwy wierzchniej stali narzędziowych do pracy na gorąco. Przedstawiono również wyniki badań oraz obserwacji oddziaływania (obecności) zgorzeliny z materiału odkuwki na stale narzędziowe do pracy na gorąco. Analizę oparto na wynikach badań przeprowadzonych w przemyśle oraz wynikach testów wykonanych w laboratorium badawczym. Szczegółowe badania dotyczyły: analiz termowizyjnych zjawisk podczas kucia na gorąco odkuwek stalowych, badania mikroskopowe, badania zużycia ściernego w obecności ścierniwa (zgorzeliny z odkuwki stalowej), badania mikrotwardości dla różnych parametrów badań laboratoryjnych oraz narzędzi z procesów kucia odkuwek stalowych.
EN
This article presents the results of studies on the effects of elevated temperatures on the properties of the surface layer of hot tool steels. The results of investigations and observations of the impact (presence) of the scale from the forging material on the tool steels for hot work were also presented. The analysis is based on the results of research conducted in the industry and the results of tests performed in the research laboratory. Detailed investigations concerned thermal analysis of steel forging, microscopic examination, abrasive wear in the presence of abrasive (steel forgings), microhardness tests for various laboratory tests and tools for forging of steel forgings.
PL
W pracy przedstawiono wyniki termomechanicznej symulacji procesu wieloetapowego kucia wydłużającego stali stopowej z wykorzystaniem metody elementów skończonych. Analizę dla przestrzennego stanu odkształcenia oparto o rozkład intensywności odkształcenia, naprężeń średnich i temperatury, z uwzględnieniem warunków brzegowych stosowanych w praktyce przemysłowej. Rezultaty badań uzupełniono o prognozowanie powstawania pęknięć ciągliwych podczas kucia. Dokonano oceny wpływu stopnia przekucia na wartości i lokalizację odkształceń, naprężeń i wskaźnika powstawania pęknięć. Wyniki teoretyczne poddano weryfikacji eksperymentalnej.
EN
Finite element method was employed to model plastic flow and heat transfer in the multistage cogging process of alloy steel using the finite element method. The analysis for three-dimensional state of strain was based on distribution of the effective strain, mean stresses and temperature assuming boundary conditions used in industrial practice. The results of the studies have been complemented with the prediction of cracks during forging. The influence of forging ratio on the values and location of strain, stress and the damage factor has been estimated. The results are compared with the experimental data.
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