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C. J. Tyne - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Die Strength and Work Piece Strength on the Wear of Hot Forging Dies
    Journal of Materials Engineering and Performance, 2015
    Co-Authors: B. S. Levy, C. J. Tyne
    Abstract:

    The effect of the strength ratio extracted from an Archard model for wear is used to describe the wear rates expected in Hot Forging dies. In the current study, the strength ratio is the strength of the Hot Forging die to the strength of the work piece. Three Hot Forging die steels are evaluated. The three die steels are FX, 2714, and WF. To determine the strength of the Forging die, a continuous function has been developed that describes the yield strength of three die steels for temperatures from 600 to 700 °C and for times up to 20 h (i.e., tempering times of up to 20 h). The work piece material is assumed to be AISI 1045. Based on the analysis, the wear resistance of WF should be superior and FX should be slightly better than 2714. Decreasing the Forging temperature increases the strength ratio, because the strength of the die surface increases faster than the flow strength of AISI 1045. The increase in the strength ratio indicates a decrease in the expected wear rate.

Sergio Tonini Button - One of the best experts on this subject based on the ideXlab platform.

  • Expert system for Hot Forging design
    Journal of Materials Processing Technology, 1998
    Co-Authors: Ângelo Caporalli, Luciano Antonio Gileno, Sergio Tonini Button
    Abstract:

    Planning Hot Forging processes is a time-consuming activity with high costs involved because of the trial-and-error iterative methods used to design dies and to choose equipment and process conditions. Some processes demand many months to produce forged parts with controlled shapes, dimensions and microstructure. This paper shows how expert systems can help engineers to reduce the time needed to design precision forged parts and dies from machined parts. The software ADHFD interfacing MS Visual Basic v.5.0 and SolidEdge v.3.0 was used to design flashless Hot forged gears, chosen from families of gears.

B. S. Levy - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Die Strength and Work Piece Strength on the Wear of Hot Forging Dies
    Journal of Materials Engineering and Performance, 2015
    Co-Authors: B. S. Levy, C. J. Tyne
    Abstract:

    The effect of the strength ratio extracted from an Archard model for wear is used to describe the wear rates expected in Hot Forging dies. In the current study, the strength ratio is the strength of the Hot Forging die to the strength of the work piece. Three Hot Forging die steels are evaluated. The three die steels are FX, 2714, and WF. To determine the strength of the Forging die, a continuous function has been developed that describes the yield strength of three die steels for temperatures from 600 to 700 °C and for times up to 20 h (i.e., tempering times of up to 20 h). The work piece material is assumed to be AISI 1045. Based on the analysis, the wear resistance of WF should be superior and FX should be slightly better than 2714. Decreasing the Forging temperature increases the strength ratio, because the strength of the die surface increases faster than the flow strength of AISI 1045. The increase in the strength ratio indicates a decrease in the expected wear rate.

Bernd-arno Behrens - One of the best experts on this subject based on the ideXlab platform.

  • Numerical die life estimation of a crack susceptible industrial Hot Forging process
    2017
    Co-Authors: Anas Bouguecha, Bernd-arno Behrens, Christian Bonk, Daniel Rosenbusch, Mohammad Kazhai
    Abstract:

    In industrial Hot Forging processes, the Forging dies underlie cyclic thermo-mechanical loads, which can lead to failure of the tools. Besides die wear (abrasive and adhesive) on the surface, fatigue crack initiation with a following fracture of the tool is one of the most frequent failures occurring in Hot Forging processes. In this study an industrial Hot Forging process is considered for fatigue analysis. Tool geometry is designed for a defined life time until crack initiated failure of the tool. Material characterization tests in form of tensile tests as well as cylindrical compression tests and low cycle fatigue tests were carried out. The data will be implemented in a commercial software-system to realize a qualitative good prediction of die life regarding crack wiation.

  • preform optimization for Hot Forging processes using genetic algorithms
    The International Journal of Advanced Manufacturing Technology, 2017
    Co-Authors: Johannes Knust, Bernd-arno Behrens, Florian Podszus, Malte Stonis, Ludger Overmeyer, Georg Ullmann
    Abstract:

    In multi-stage Hot Forging processes, the preform shape is the parameter mainly influencing the final Forging result. Nevertheless, the design of multi-stage Hot Forging processes is still a trial and error process and therefore time-consuming. The quality of developed Forging sequences strongly depends on the engineer’s experience. To overcome these obstacles, this paper presents an algorithm for solving the multi-objective optimization problem when designing preforms. Cross-wedge-rolled (CWR) preforms were chosen as subject of investigation. An evolutionary algorithm is introduced to optimize the preform shape taking into account the mass distribution of the final part, the preform volume, and the shape complexity. The developed algorithm is tested using a connecting rod as a demonstration part. Based on finite element analysis, the implemented fitness function is evaluated, and thus the progressive optimization can be traced.

  • Influence of heat pipe cooling on the wear of Hot Forging dies
    Production Engineering, 2016
    Co-Authors: Bernd-arno Behrens, Anas Bouguecha, Jan Puppa, Adis Huskic, Kai Brunotte, Tobias Prüß
    Abstract:

    The temperature of Hot Forging dies has a high influence on the wear of tool surfaces. In order to reduce the thermal impact on tool life, passively acting heat pipes are tested and the results are presented within this paper. For this purpose, the upper die of a commonly used Hot Forging tool was equipped with heat pipes and serial Forging trials have been performed. The influence of the heat pipes on the die temperature as well as the effects on wear behavior are presented. The heat pipe cooling leads to a lower die temperature and thus to a reduction of adhesive wear. The wear is examined by optical and tactile measurements as well as by micrograph analyses. Conclusively, hardness tests of the tool edge layer are carried out.

  • Numerical Investigation for the Design of a Hot Forging Die with Integrated Cooling Channels
    Procedia Technology, 2016
    Co-Authors: Bernd-arno Behrens, Anas Bouguecha, Milan Vucetic, Martin Bonhage, Irfan Yousaf Malik
    Abstract:

    Abstract Ongoing research at the Institute of Forming Technology and Machines (IFUM) within the scope of sub-project E3 of the Collaborative Research Centre 653 deals with the generation of controlled cavities inside a sintered Hot Forging die. The primary objective of sub-project E3 is to develop a Forging die which can “feel”, “learn” and “control” autonomous reactions to process variations. The current project stage aims at developing a Hot Forging die with integrated cooling channels. This paper presents the findings of numerical investigations carried out to analyze the Hot Forging die made of tool steel powder and equipped with internal cooling channels. Two different geometric variations have been numerically investigated in order to study the stress states within the die under process boundary conditions.

  • Influence of the fabrication method on the wear resistance of Hot Forging dies
    Production Engineering, 2012
    Co-Authors: Bernd-arno Behrens, Timur Yilkiran
    Abstract:

    Tools used for Hot Forging are subject to simultaneously acting process-related high mechanical, tribological, chemical and thermal cyclic loads. In comparison to other manufacturing methods, the resulting load spectrum leads to a failure of the form-giving tool components after a short tool life. Wear is the main reason for die failure in Hot Forging processes, accounting for 70 % of all causes. Other kinds of failures are thermal and mechanical cracks as well as plastic deformation (a result of the loss of hardness due to the high thermal charge). In order to reduce wear, several kinds of wear reducing methods are subject of industrial applications as well as research works. For example, nitriding and optional thin hard coating or overlay welding are effective methods to increase the wear resistance of Hot Forging dies. Beside the process related stresses during the service, manufacturing of Forging tools itself initializes microstructural changes in their subsurface zones. During fabrication, the general influence of the fabrication method on the tool lifetime has not been considered so far. The implementation of the knowledge of this influence into the fabrication process could lead to an increased productivity of Hot Forging processes without using expensive and complex wear reducing methods.

Mustafa Ilhan Gokler - One of the best experts on this subject based on the ideXlab platform.

  • wear analysis of Hot Forging dies
    Tribology International, 2010
    Co-Authors: Siamak Abachi, Metin Akkok, Mustafa Ilhan Gokler
    Abstract:

    In Hot Forging, die wear is the main cause of failure. In this paper, the wear analysis of a closed Hot Forging die used at the final stage of a component has been realized. The simulation of Forging process was carried out by commercially available software based on finite volume method and the depth of wear was evaluated with a constant wear coefficient. By comparing the numerical results with the measurement taken from the worn die, the wear coefficient has been evaluated for different points of the die surface and finally a value of wear coefficient is suggested.