Design method and verification for long life hot forging die

Abstract

During the forging process, hot forging dies can easily sustain damage, including thermal softening, crack extension, wear and so on. The existing homogeneous hot forging die steel cannot meet the service performance requirements. However, the strengthening technology based on functionally gradient material (FGM) technology and surface cladding together can relieve the thermal stress. Based on the zoning of the temperature field distribution during continuous working, the structural design method and preparation process for the long life hot forging die are proposed in this paper; meanwhile, multilayer metal coating based on FGM was carried out and the temperature field, the stress field distribution for the homogeneous materials and the multilayer metal material hot forging die were analysed and compared. The results prove that using long service life hot forging die technology combined with FGM and surface cladding can relieve the overall stress value.

Keywords:

• Long service life hot forging die
• Structural design
• Preparation process
• Coating

The research is sponsored by the National Natural Science Foundation of China (no. 50675165) and Fundamental Research Funds for the Central Universities of China (no. 2010‐II‐025). The authors would like to thank Vice Professor A. N. Li for conducting the plasma cladding experiments and the tests.