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Numerical analysis of three-stage the forming process hollow forgings with an outer flange

Wójcik Łukasz, Bulzak Tomasz, Winiarski Grzegorz, Szala Mirosław

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2020

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nr 62 (134)

142--147

EN

This article presents the results of computer simulations used to investigate the forming of a hollow coldworked forging with an outer flange. Numerical simulations were performed in Deform 2D/3D using a calculation module for axial-symmetric cases. A ϕ57×12.5 mm tube-shaped billet from 42CrMo4 grade steel was used. The forming process involved two and three stages, consisting of extrusion the shaft portion and forging the flange. The objective of this research was to determine the accuracy of the forming process used to produce the hollow part. This technology was analyzed using the effective strain distributions, the Cockcroft-Latham fracture criterion values, and the forming force progression. The results showed that it was possible to use this three-stage process to forge elements from a tube-shaped billet.

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Właściwości reologiczne stopu Zr-Nb w warunkach kucia promieniowego na gorąco

Ożmiegow K. W., Kawałek A., Gałkin A. M., Knapiński M.

Hutnik, Wiadomości Hutnicze

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2012

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Vol. 79, nr 5

353--357

PL

W pracy przedstawiono wyniki badań plastometrycznych zrealizowanych przy obciążaniu ciągłym i pojedynczym próbek ze stopu cyrkonu typu Zr-Nb, za pomocą symulatora procesów metalurgicznych Gleeble 3800. Badania wykonano przy zmiennych temperaturach (T = 350÷500 °С) i zmiennej prędkości odkształcenia w granicach 0,5÷15,0 s-1. Porównano także wyniki badań eksperymentalnych i teoretycznych dla krzywych płynięcia plastycznego σp − ε , otrzymanych przy wykorzystaniu modelu reologicznego, opartego na równaniach dotyczących czynnika dziedzicznego, przeprowadzonych zgodnie z teorią pełzania materiałów.

EN

The paper presents the results of the plastometric tests executed in continuous and fractional loading of samples made from the Zr-Nb alloy, using the thermal-mechanical physical simulator Gleeble 3800. The researches were carry out with changing values of the temperature in range (T = 350÷500 °С) and changing values of the strain rate inrange 0,5÷15,0 s-1. The results of experimental and theoretical investigations were also compared for plastic flow curves, received by using the rheological model, leaning on the equations relate to the hereditary factor, conducted according to the theory of the creeping materials.

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Analiza wpływu parametrów kucia promieniowego prętów na siłę nacisku całkowitego

Ożmiegow K. W., Dyja H., Gałkin A. M., Kawałek A.

Hutnik, Wiadomości Hutnicze

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2011

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Vol. 78, nr 9

825--827

PL

Do wytwarzania prętów okrągłych ze stopów cyrkonu stosowane są kuźniarki promieniowe. W pracy przedstawiono wyniki badań nad wpływem naprężenia uplastyczniającego σp i parametrów technologicznych kucia promieniowego: kąta stożka kształtującego α, długości części zgniatającej kowadła i współczynnika tarcia μ na zmianę wartości całkowitej siły nacisku. Określono zakres temperatury przeróbki plastycznej kutego stopu oraz technologiczne parametry procesu kucia i parametry kowadeł, zapewniające obniżenie całkowitej sił nacisku w procesie kucia promieniowego w kuźniarce SKK-14.

EN

The radial forging machines are used for round adial zirconium bars production. In the work the results of research concerning the inflfl u-- ence of the flow stress σp and technological parameters of radial forging: an angle of working cone inclination α, a length of working part of anvil lzgn and a friction coefficient on values of total load were presented. Moreover, the range of investigated alloy temperature, technological parameters of the forging process and anvils geometry which guarantee the reduction of the total load during process in SKK-14 radial horizontal forging machine were obtained.

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Hot forming and heat treatment simulation in a steel mill

Redl C., Tian B, Wieser V., Sommitsch C.

Computer Methods in Materials Science

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2007

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Vol. 7, No. 1

5-10

EN

Numerical simulation is nowadays becoming a standard tool in industrial processes. This paper provides an insight about the usage of finite element calculations in the development and production process in the steel mill of Böhler Edelstahl GmbH, Kapfenberg, Austria. Simulation methods are used all along the value chain at the mill starting with melting and casting of the steel. Nevertheless this paper focuses on the simulation of hot forming and heat treatment as well as on the simulations done as a service for our customers. The activities of finite element simulation of hot rolling concentrate on one side on the basic principles, for example, widening, strain distributions, grain models etc. On the other side, typical chains of hot rolling have been simulated and the results verified by comparing measured parameters with calculations. As an example the widening of a cold work steel at different temperatures is presented and compared with other steel grades. Considering as example a hot work tool steel of type 1.2343 the production chain from forging over the pre heat treatment at the mill to the application as a tool for aluminium extrusion is surveyed. The forming of the casted and remelted steel block is done on a radial forging machine of the type GFM SX55. The simulation takes into account five passes and delivers strains and temperatures within the work piece. Afterwards the pre heat treatment cycle of the part consisting of heating, quenching in polymer solution and subsequent air cooling is modelled. Simulation services are provided to the customers to optimize the material selection for their specific applications. The aforementioned tool steel is used as liner or die material in the extrusion industry. By a combination of a visco-plastic material model and a damage model it is necessary to predict the lifetime of the tools in use. In order to obtain the residual stresses and phase distribution after nitrogen quenching a heat treatment simulation of the die is performed. Afterwards a simulation of the extrusion process is carried out to get the distribution of effective stress and temperature in the die. The calculated life time as well as the predicted location of the maximum damage agrees well with observations from real extrusion processes.