Abstract
Aiming at the quality issues such as shrinkage porosity, misrun, and cold shut often occurring during the development of lost foam casting rump pan assembled on the middle trough of the scraper conveyor, numerical simulation and process optimization of cast steel rump pan produced by lost foam casting were carried out using the InteCAST software. The results indicate that for the original process scheme, shrinkage porosities are mainly distributed in the connection point between the shovel plate and the M-shaped groove, especially in the connection position between the shovel plate base and the ribs. These defects are likely to appear in the thick parts of the ribs and thrust lugs at both ends. For the optimized process scheme, the mold filling process presents stable, and the riser/gate has a satisfied feeding effect on the casting during solidification, with absence of shrinkage porosity defects in major parts of the casting. The optimized process was adopted for batch production and verification, and the absence of defects such as shrinkage porosity and misrun was observed.
1. Introduction
The rump pan, as a critical component of scraper conveyors, plays a vital role in coal mining and other industrial applications. However, traditional casting methods often lead to defects such as shrinkage porosity, misrun, and cold shut, which significantly affect the performance and lifespan of the rump pan. Lost foam casting, as an advanced casting technology, offers numerous advantages, including near-net-shape casting, reduced machining costs, and improved dimensional accuracy. In this study, we focus on the numerical simulation and process optimization of lost foam casting for rump pan to address these quality issues.
Table 1. Comparison of Traditional and Lost Foam Casting Methods
| Casting Method | Traditional Casting | Lost Foam Casting |
|---|---|---|
| Material Waste | High | Low |
| Machining Costs | High | Low |
| Dimensional Accuracy | Low | High |
| Casting Defects | Common (Shrinkage, Misrun, etc.) | Reduced |
2. Methodology
2.1. Numerical Simulation
Numerical simulation was conducted using the InteCAST software to analyze the lost foam casting process of the rump pan. The simulation included mold filling, solidification, and cooling stages, aiming to predict potential defects and optimize the casting process.
2.2. Process Optimization
Based on the simulation results, several process parameters were optimized, including pouring temperature, gating system design, and riser configuration. The goal was to improve mold filling stability and enhance feeding effects during solidification to reduce defects.
3. Results and Discussion
3.1. Simulation Results of the Original Process Scheme
The simulation results of the original process scheme revealed significant shrinkage porosities mainly distributed in the connection point between the shovel plate and the M-shaped groove, especially in the connection position between the shovel plate base and the ribs. Additionally, defects were likely to appear in the thick parts of the ribs and thrust lugs at both ends.
3.2. Optimization of the Casting Process
To address the defects identified in the original process scheme, several optimizations were implemented:
- Pouring Temperature Adjustment: The pouring temperature was adjusted to ensure a smooth mold filling process and reduce the risk of misrun and cold shut defects.
- Gating System Design: The gating system was redesigned to improve flow distribution and enhance feeding effects during solidification.
- Riser Configuration: Additional risers were added to provide better feeding to critical areas of the casting, reducing shrinkage porosity.
3.3. Simulation Results of the Optimized Process Scheme
After implementing the optimizations, the simulation results showed a stable mold filling process and improved feeding effects during solidification. The important parts of the casting were free of shrinkage porosity defects.
4. Experimental Verification
The optimized process scheme was adopted for batch production and verification. Castings were inspected for defects such as shrinkage porosity, misrun, and cold shut. The results showed that the castings produced using the optimized process were free of these defects, confirming the effectiveness of the optimizations.
Table 2. Defect Rates Before and After Process Optimization
| Defect Type | Before Optimization | After Optimization |
|---|---|---|
| Shrinkage Porosity | High | None |
| Misrun | Moderate | None |
| Cold Shut | Low | None |
5. Conclusions
This study focused on the numerical simulation and process optimization of lost foam casting for rump pan. The simulation results of the original process scheme revealed significant shrinkage porosities in critical areas. Through adjustments in pouring temperature, gating system design, and riser configuration, the optimized process scheme achieved a stable mold filling process and improved feeding effects during solidification. Experimental verification confirmed the effectiveness of the optimizations, with castings produced using the optimized process being free of defects such as shrinkage porosity, misrun, and cold shut. The findings of this study provide valuable insights for improving the quality of lost foam castings and can be applied to other casting components.