# Simulation of Cross Wedge Rolling and Hot Extrusion-Combined Forming Process for Axle Sleeve

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## Abstract

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## 1. Introduction

## 2. Forming Process Design for the Axle Sleeve

## 3. Numerical Simulation

#### 3.1. The Finite Element Model of CWR

#### 3.2. The Finite Element Model of Hot Extrusion

## 4. Numerical Simulation Results

#### 4.1. Numerical Simulation Analysis of CWR

#### 4.1.1. The Forming Results

#### 4.1.2. Analysis of Stress Distribution

#### 4.1.3. Analysis of Strain Distribution

#### 4.1.4. Analysis of Axial Displacement

#### 4.1.5. Analysis of Rolling Force

#### 4.2. Numerical Simulation Analysis of Hot Extrusion

#### 4.2.1. Analysis of the Workpiece Temperature

#### 4.2.2. Analysis of Metal Flow Velocity

#### 4.2.3. Analysis of the Effective Stress

#### 4.2.4. Analysis of the Effective Strain and Extrusion Force

## 5. Experimental Verification

## 6. Conclusions

- The process of forming the axle sleeve via CWR and hot extrusion is simulated using the finite element method. The change rule of stress and strain of the billet during the forming process is shown, and the forming mechanism of the axle sleeve is revealed. The workpiece can achieve diameter compression and wall thickness reduction through high compressive stress between the die and mandrel, which is beneficial to improve the quality performance of the rolled piece.
- Through the analysis of finite element numerical simulation results combined with experimental verification, the results show the feasibility of the combined CWR and hot extrusion process for producing an axle sleeve.
- In the process of hot extrusion, the temperature of the main deformation parts of the workpiece is within the temperature range of good forming, the metal streamline is continuous and uniform, the effective stress and effective strain are not large and evenly distributed and high-quality parts can be obtained.
- The rolling force of CWR is one order of magnitude lower than the extrusion force of hot extrusion. The use of the CWR process can effectively reduce the load and weight of equipment.
- CWR can effectively improve the eccentricity of the inner hole of the billet. The internal and external steps of the axle sleeve obtained through the combination of CWR and hot extrusion are formed well. The flange is well formed, and the metal streamline is continuous. The axis of the inner hole does not easily deviate, and the wall thickness is symmetrically distributed along the axis. The product quality is good, and the production efficiency is high.

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## References

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**Figure 1.**Part drawing and forming process route of the axle sleeve: (

**a**) part drawing; (

**b**) billet; (

**c**) punching; (

**d**) CWR; (

**e**) hot extrusion.

**Figure 4.**(

**a**) FE simulation results of CWR of the axle sleeve; (

**b**) profile of FE simulation results.

**Figure 6.**Stress distribution on the cross section in the knifing zone: (

**a**) transverse stress; (

**b**) radial stress; (

**c**) axial stress; (

**d**) effective stress.

**Figure 7.**Stress distribution on the longitudinal section in the knifing zone: (

**a**) transverse stress; (

**b**) radial stress; (

**c**) axial stress; (

**d**) effective stress.

**Figure 8.**Stress distribution on the cross section in the stretching zone: (

**a**) transverse stress; (

**b**) radial stress; (

**c**) axial stress; (

**d**) effective stress.

**Figure 9.**Stress distribution on the longitudinal section in the stretching zone: (

**a**) transverse stress; (

**b**) radial stress; (

**c**) axial stress; (

**d**) effective stress.

**Figure 10.**Strain distribution on the cross section in the stretching zone: (

**a**) transverse strain; (

**b**) radial strain; (

**c**) axial strain.

**Figure 11.**Strain distribution on the longitudinal section in the stretching zone: (

**a**) transverse strain; (

**b**) radial strain; (

**c**) axial strain.

**Figure 12.**Effective strain distribution on the cross section in the process of CWR of the axle sleeve: (

**a**) knifing zone; (

**b**) stretching zone; (

**c**) sizing zone.

**Figure 13.**Effective strain distribution on the longitudinal section in the process of CWR of the axle sleeve: (

**a**) knifing zone; (

**b**) stretching zone; (

**c**) sizing zone.

**Figure 16.**The change in workpiece temperature in the hot extrusion process: (

**a**) initial stage of the extrusion; (

**b**) middle stage of the extrusion; (

**c**) final stage of the extrusion.

**Figure 17.**Simulation results of metal flow velocity during the hot extrusion process: (

**a**) initial stage of the extrusion; (

**b**) middle stage of the extrusion; (

**c**) final stage of the extrusion.

**Figure 18.**Simulation results of effective stress during the hot extrusion process: (

**a**) initial stage of the extrusion; (

**b**) middle stage of the extrusion; (

**c**) final stage of the extrusion.

**Figure 19.**Effective strain distribution in the final stage of the extrusion: (

**a**) vertical view; (

**b**) main view.

**Figure 21.**Results of CWR experiment: (

**a**) outline drawing and section drawing of the rolled piece; (

**b**) inner hole deviation correction results of CWR.

FE Parameter (Unit) | Value |
---|---|

Speed of roller (rpm) | 10 |

Initial temperature of workpiece (°C) | 1100 |

Initial temperature of tool (°C) | 20 |

Environment reference temperature (°C) | 20 |

Heat convection coefficient with air (N/s/mm/°C) | 0.02 |

Contact heat transfer coefficient (N/s/mm/°C) | 11 |

Emissivity | 0.8 |

Friction factor (workpiece and die) | 1 |

Friction factor (workpiece and guide plate) | 0.2 |

Initial element number of workpiece | 1.1 × 10^{5} |

FE Parameter (Unit) | Value |
---|---|

Speed of the top die (mm/s) | 30 |

Initial temperature of workpiece (°C) | 1050 |

Initial temperature of the top die (°C) | 300 |

Initial temperature of the bottom die (°C) | 400 |

Environment reference temperature (°C) | 20 |

Heat convection coefficient with air (N/s/mm/°C) | 0.02 |

Contact heat transfer coefficient (N/s/mm/°C) | 5 |

Emissivity | 0.8 |

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## Share and Cite

**MDPI and ACS Style**

Sun, W.; Yang, C.
Simulation of Cross Wedge Rolling and Hot Extrusion-Combined Forming Process for Axle Sleeve. *Metals* **2023**, *13*, 1017.
https://doi.org/10.3390/met13061017

**AMA Style**

Sun W, Yang C.
Simulation of Cross Wedge Rolling and Hot Extrusion-Combined Forming Process for Axle Sleeve. *Metals*. 2023; 13(6):1017.
https://doi.org/10.3390/met13061017

**Chicago/Turabian Style**

Sun, Wenhui, and Cuiping Yang.
2023. "Simulation of Cross Wedge Rolling and Hot Extrusion-Combined Forming Process for Axle Sleeve" *Metals* 13, no. 6: 1017.
https://doi.org/10.3390/met13061017