Study on fold formation mechanism and process optimization in multi-directional die forged valve bodies

Area of Science:

• Manufacturing Engineering
• Materials Science

Background:

• Fold defects are a significant problem in multi-directional die forging of complex valve bodies.
• These defects lead to product rejection and increased manufacturing costs.

Purpose of the Study:

• To develop a simulation model for predicting and understanding fold defect formation.
• To identify optimal process parameters for minimizing fold defects in valve body forging.

Main Methods:

• A 3D thermo-mechanical coupled finite element (FE) model was created using Forge® software.
• The "marking grid" and "sensors" functionalities were used to track fold evolution.
• Orthogonal experiments and ANOVA were employed to analyze process parameters.

Main Results:

• The friction coefficient significantly impacts fold depth and damage, followed by billet temperature; punch speed has minimal effect.
• Optimal parameters identified: friction coefficient of 0.1, billet temperature of 1200 °C, and punch speed of 30 mm/s.
• Simulations accurately predicted defect-free outcomes.

Conclusions:

• The optimized process parameters effectively prevent fold and crack defects in forged valve bodies.
• The FE model provides a reliable tool for optimizing complex forging processes.
• Validation through production trials confirms the simulation's effectiveness.