Design, Characterisation and Numerical Investigations of Additively Manufactured H10 Hybrid-Forging Dies with Conformal Cooling Channels

Behrens, Bernd‐Arno; Huskic, Aziz; Rosenbusch, Daniel; Peddinghaus, Julius; Wester, Hendrik; Siegmund, Martin; Giedenbacher, Jochen; Siring, Janina

doi:10.3390/met12071063

“…To prevent early and unexpected failure of the tools due to the high cyclic thermal and mechanical loads, the tools are often designed by using finite-element calculations. It is state of the art to use a linear elastic analysis by comparing the equivalent von Mises stress with the yield strength of the material and the maximum principle stress with the tensile strength of the material [5]. However, the occurring stress in service can locally (e.g., in fillet radii and other notches) exceed the materials' yield strength.…”

Section: Introductionmentioning

confidence: 99%

A Temperature-Dependent Viscoplasticity Model for the Hot Work Steel X38CrMoV5-3, Including Thermal and Cyclic Softening under Thermomechanical Fatigue Loading

Schlayer

¹

,

Warwas

²

,

Seifert

³

2023

Materials

0

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In this paper, a temperature-dependent viscoplasticity model is presented that describes thermal and cyclic softening of the hot work steel X38CrMoV5-3 under thermomechanical fatigue loading. The model describes the softening state of the material by evolution equations, the material properties of which can be determined on the basis of a defined experimental program. A kinetic model is employed to capture the effect of coarsening carbides and a new isotropic cyclic softening model is developed that takes history effects during thermomechanical loadings into account. The temperature-dependent material properties of the viscoplasticity model are determined on the basis of experimental data measured in isothermal and thermomechanical fatigue tests for the material X38CrMoV5-3 in the temperature range between 20 and 650 ∘C. The comparison of the model and an existing model for isotropic softening shows an improved description of the softening behavior under thermomechanical fatigue loading. A good overall description of the experimental data is possible with the presented viscoplasticity model, so that it is suited for the assessment of operating loads of hot forging tools.

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“…This depends in particular on the thermomechanical and tribological loads during forming, the material properties of the die material and the design of the die engraving [1]. The mechanical stresses increase as the forging or the dynamic pressure progresses and reach their maximum at the end of the forming process [2]. The temperature peak of the forging cycle is also at this point, which leads to a maximum of the load spectrum.…”

Section: Introductionmentioning

confidence: 99%

Investigation into the Manufacture of Hybrid Wear Resistant Forging Tools using Tailored Forming Technology

Till

2023

9th ECCOMAS Thematic Conference on the Mechanical Response of Composites

0

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Forging tools that are subject to high thermo-mechanical loads require a correspondingly high heat resistance, hardness and ductility to prevent undesirable failure patterns due to wear, plastic deformation and crack formation. These properties are mainly required in the layer of the tool engraving close to the surface, as this area is exposed to the highest loads due to the contact with the hot workpiece. With the heat transfer from the workpiece to the tool, a cyclic tempering process of the tool material often occurs in this area, resulting in a decrease in wear resistance. Diffusion treatments of the tool surface, such as additional nitriding, cannot provide sufficient protection in thermally highly stressed tool areas, as the heat-affected zone in these areas extends beyond the surface modification. As a result, a tempered layer forms under the nitrided layer, on which it can slide off or break as a result of the high process loads and the wear protection is lost. The use of nickel-based alloys promises an improvement in service life due to their high specific heat. However, these alloys are much more expensive than hot-work tool steels and are more difficult to machine, which has a negative effect on the economic use as a die material. Furthermore, nickel-based alloys do not have the high strength of steel that is often required in the base material that is subject to low thermal loads. To reduce the material usage of nickel-based alloys, but to fully take advantage of their positive properties, the suitability of the Tailored Forming concept in thermo-mechanically highly stressed areas were investigated within the scope of this research. For this reason, hybrid forging tool inserts with a base material of hot-work tool steel and a protective nickel-based alloy surface layer were produced. The hybrid tools are manufactured through a process combination of rotatory friction welding and die forging. The surface enlargement as a result of the forming process is to be used specifically to protect the relevant tool areas with a layer of nickel-based alloy and at the same time minimize the use of the expensive material. The effects of the thermo mechanical treatments occurring in the joining zone were examined and the potential of the technology was investigated.

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“…This depends in particular on the thermomechanical and tribological loads during forming, the material properties of the die material and the design of the die engraving [1]. The mechanical stresses increase as the forging or the dynamic pressure progresses and reach their maximum at the end of the forming process [2]. The temperature peak of the forging cycle is also at this point, which leads to a maximum of the load spectrum.…”

Section: Introductionmentioning

confidence: 99%

Investigation into the Manufacture of Hybrid Wear Resistant Forging Tools using Tailored Forming Technology

Till

2023

9th ECCOMAS Thematic Conference on the Mechanical Response of Composites

0

View full text Add to dashboard Cite

Forging tools that are subject to high thermo-mechanical loads require a correspondingly high heat resistance, hardness and ductility to prevent undesirable failure patterns due to wear, plastic deformation and crack formation. These properties are mainly required in the layer of the tool engraving close to the surface, as this area is exposed to the highest loads due to the contact with the hot workpiece. With the heat transfer from the workpiece to the tool, a cyclic tempering process of the tool material often occurs in this area, resulting in a decrease in wear resistance. Diffusion treatments of the tool surface, such as additional nitriding, cannot provide sufficient protection in thermally highly stressed tool areas, as the heat-affected zone in these areas extends beyond the surface modification. As a result, a tempered layer forms under the nitrided layer, on which it can slide off or break as a result of the high process loads and the wear protection is lost. The use of nickel-based alloys promises an improvement in service life due to their high specific heat. However, these alloys are much more expensive than hot-work tool steels and are more difficult to machine, which has a negative effect on the economic use as a die material. Furthermore, nickel-based alloys do not have the high strength of steel that is often required in the base material that is subject to low thermal loads. To reduce the material usage of nickel-based alloys, but to fully take advantage of their positive properties, the suitability of the Tailored Forming concept in thermo-mechanically highly stressed areas were investigated within the scope of this research. For this reason, hybrid forging tool inserts with a base material of hot-work tool steel and a protective nickel-based alloy surface layer were produced. The hybrid tools are manufactured through a process combination of rotatory friction welding and die forging. The surface enlargement as a result of the forming process is to be used specifically to protect the relevant tool areas with a layer of nickel-based alloy and at the same time minimize the use of the expensive material. The effects of the thermo mechanical treatments occurring in the joining zone were examined and the potential of the technology was investigated.

show abstract

Design, Characterisation and Numerical Investigations of Additively Manufactured H10 Hybrid-Forging Dies with Conformal Cooling Channels

Cited by 5 publications

References 25 publications

A Temperature-Dependent Viscoplasticity Model for the Hot Work Steel X38CrMoV5-3, Including Thermal and Cyclic Softening under Thermomechanical Fatigue Loading

A Temperature-Dependent Viscoplasticity Model for the Hot Work Steel X38CrMoV5-3, Including Thermal and Cyclic Softening under Thermomechanical Fatigue Loading

Investigation into the Manufacture of Hybrid Wear Resistant Forging Tools using Tailored Forming Technology

Investigation into the Manufacture of Hybrid Wear Resistant Forging Tools using Tailored Forming Technology

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