Process design of large-scale ductile iron castings

- Jan 10, 2021-

During the process design, computer simulation is used as a reference to avoid randomness in process design.

Abnormal metallographic structure of castings, such as too few graphite balls, obvious intergranular segregation, deterioration of graphite shape, etc., will greatly reduce the low-temperature impact toughness and fatigue strength. There are shrinkage holes, shrinkage porosity or slag inclusions inside the castings, which will also cause a significant decrease in low-temperature impact toughness and fatigue strength. Therefore, strictly control the metallographic structure of the casting.

A complete process control system is established in the production process to reduce the process parameter variables of each process to a minimum. In terms of cast iron smelting, there should be a system for controlling the quality of the charge and various raw materials to be consistent, there should be a means to ensure small fluctuations in chemical composition, and there should be a stable spheroidization and inoculation process.