Investigation of Dendrite Coarsening in Complex Shaped Lamellar Graphite Iron Castings
Abstract
:1. Introduction
2. Materials and Methods
2.1. Shrinkage Porosity (SP)
2.2. Metal Expansion Penetration (MEP)
2.3. Microstructure Investigation
2.4. Morphologic Parameters
2.5. Numerical Simulation of the Local Solidification Time
3. Results and Discussion
3.1. Shrinkage Porosity (SP)
3.2. Metal Expansion Penetration (MEP)
4. Conclusions
- (1)
- The coarsening phenomena was observed in two different complex shaped castings.
- (2)
- The local solidification time influences the austenite morphology in complex shaped castings, which is in agreement with previous observations in compact shaped cylindrical castings.
- (3)
- A variation in local solidification time within the same complex shaped casting leads to the formation of a morphological gradient, which can be considered as the transport path for the intradendritic liquid in forming a shrinkage porosity defect or a metal expansion penetration defect.
- (4)
- The morphological parameter observations in complex shaped casting are disturbed due to morphological changes like a dendrite fragmentation and coalescence.
Acknowledgments
Author Contributions
Conflicts of Interest
Appendix A
- Alloy
- Material: GJL-150
Temperature (°C) | CP (J·kg−1 K−1) | fS | k (W·m−1·K−1) | ρ (kg·m−3) |
---|---|---|---|---|
1 | 450 | - | 54.0 | 7100.0 |
25 | 467 | - | - | - |
100 | 506 | - | 52.5 | 7074.5 |
200 | 563 | - | 51.0 | 7049.1 |
300 | 621 | - | 50.0 | 7023.8 |
400 | 663 | - | 49.0 | 6998.6 |
500 | 741 | - | 48.5 | - |
600 | 851 | - | - | - |
700 | 1036 | - | - | - |
725 | 1100 | - | - | - |
810 | 744 | - | - | - |
900 | 774 | - | - | - |
1000 | 804 | - | - | 6850.6 |
1100 | 830 | - | - | - |
1160 | 844 | 1.000 | 40.0 | 6814.0 |
1161 | - | 0.830 | - | - |
1162 | - | 0.530 | - | - |
1163 | - | 0.180 | - | - |
1164 | - | 0.040 | - | - |
1166 | - | 0.030 | - | - |
1168 | - | 0.020 | - | - |
1170 | - | 0.010 | - | - |
1173 | 740 | 0.000 | 38.0 | 6882.0 |
1200 | 747 | - | - | - |
1255 | - | - | - | 6813.9 |
1300 | 778 | - | - | - |
1355 | - | - | - | 6745.3 |
1400 | 813 | - | - | - |
1500 | 854 | - | - | - |
1600 | 871 | - | - | - |
1700 | 872 | - | - | - |
2000 | 872 | - | 38.0 | 6310.2 |
Temperature (°C) | CP (J·kg−1·K−1) | ρ (kg·m−3) | k (W·m−1·K−1) |
---|---|---|---|
1 | 700 | 1500.0 | 0.91 |
20 | - | - | 0.90 |
25 | 741 | - | - |
50 | - | - | 0.87 |
99 | 850 | - | - |
100 | 850 | 1495.0 | 0.82 |
101 | 850 | - | - |
127 | 886 | - | - |
150 | - | - | 0.79 |
200 | - | 1493.0 | 0.77 |
227 | 991 | - | - |
250 | - | - | 0.76 |
300 | - | 1490.0 | 0.74 |
326 | 1082 | - | - |
327 | 1082 | - | - |
400 | - | 1487.0 | 0.70 |
427 | 1167 | - | - |
500 | - | 1478.0 | 0.70 |
526 | 1248 | - | - |
527 | 1248 | - | - |
573 | 1285 | - | - |
574 | 1160 | - | - |
600 | - | 1476.0 | 0.70 |
627 | 1162 | - | - |
700 | - | - | 0.71 |
727 | 1167 | - | - |
750 | - | - | 0.73 |
800 | - | - | 0.76 |
827 | 1172 | - | - |
850 | - | - | 0.79 |
900 | - | - | 0.83 |
927 | 1177 | - | - |
950 | - | - | 0.88 |
1000 | - | - | 0.93 |
1027 | 1181 | - | - |
1050 | - | - | 0.99 |
1100 | - | - | 1.05 |
1127 | 1186 | - | - |
1150 | - | - | 1.12 |
1200 | 1.20 | ||
1227 | 1190 | - | - |
1327 | 1194 | - | - |
1600 | - | - | 1.40 |
2000 | 1250 | 1470.0 | 1.50 |
Temperature (°C) | h (W·m−2·K−1) |
---|---|
1 | 300 |
600 | 500 |
1100 | 600 |
1200 | 800 |
2000 | 800 |
- SP sample: 183520 metal cells out of 2473692 cells
- MEP sample: 34120 metal cells out of 206424 cells
Sample Name | Component Name | Volume (L) | Weight (kg) |
---|---|---|---|
SP sample | casting | 1.93 | 13.68 |
SP sample | mold | 16.59 | 24.87 |
MEP sample | casting | 0.37 | 2.61 |
MEP sample | mold | 1.2 | 1.8 |
Sample Name | Pouring Time (s) | Simulation Time (s) | Δt (s) | Solidification and Cooling |
---|---|---|---|---|
SP sample | 10 | 600 | 1 | time dependent |
MEP sample | 6 | 600 | 1 | time dependent |
Appendix B
Capital letters | |
Ai | Area of the intradendritic phase (m2) |
Heat capacity (J·kg−1·K−1) | |
Hydraulic diameter of the intradendritic phase (m) | |
Hydraulic diameter of the intradendritic space (m) | |
L | Latent heat of solidification (J·kg−1) |
Pi | Perimeter of the intradendritic phase (m) |
Released latent heat (J·m−3) | |
Released latent heat during solidification (W·m−3) | |
T | Temperature (°C) |
Small letter | |
fS | Fraction solidified metal (-) |
k | Thermal conductivity (W·m−1·K−1) |
t | Time (s) |
tsol | Solidification time (s) |
Greek letters | |
ρ | Density (kg·m−3) |
λ2 | Secondary dendrite arm spacing (μm) |
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Element | C | Si | Mn | P | S | Cr | Mo |
---|---|---|---|---|---|---|---|
Content in SP sample (wt %) | 3.28 | 1.96 | 0.64 | 0.03 | 0.06 | 0.26 | 0.05 |
Content in MEP sample (wt %) | 3.18 | 1.77 | 0.56 | 0.05 | 0.09 | 0.15 | 0.24 |
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Svidró, P.; Diószegi, A.; Pour, M.S.; Jönsson, P. Investigation of Dendrite Coarsening in Complex Shaped Lamellar Graphite Iron Castings. Metals 2017, 7, 244. https://doi.org/10.3390/met7070244
Svidró P, Diószegi A, Pour MS, Jönsson P. Investigation of Dendrite Coarsening in Complex Shaped Lamellar Graphite Iron Castings. Metals. 2017; 7(7):244. https://doi.org/10.3390/met7070244
Chicago/Turabian StyleSvidró, Péter, Attila Diószegi, Mohsen Saffari Pour, and Pär Jönsson. 2017. "Investigation of Dendrite Coarsening in Complex Shaped Lamellar Graphite Iron Castings" Metals 7, no. 7: 244. https://doi.org/10.3390/met7070244