1 influence of thickness and geometry
The element thickness and casting morphology determine the mechanical performance of the prototype.
During cooling, variations in section and shape influence the metal microstructure and its final properties.
2 Choice of alloy and manufacturing technique
During prototyping, the combination of metal alloy and production process is a fundamental decision.
For this reason, average data on cast iron characteristics are provided, useful for technicians to evaluate the technical and functional compliance of the prototype.
Average Data for Cast Iron Materials
The average values obtained with cast iron prototypes represent an important reference for design.
This information helps estimate the strength, hardness, and mechanical behavior of parts produced through Quick Sand Casting.
Cast Iron Microstructure
Gray cast iron microstructure:
crack propagation within gray cast iron. The crack wedges into the graphite (present in flake form) and propagates.
Spheroidal cast iron microstructure:
crack propagation within spheroidal cast iron. The crack wedges into the graphite (present in spheroidal form) and is arrested.
Appliance
- Grids
Hydraulic Applications
- Distributors
Pump Construction
- Pump body
Electronics
- Motor shields
Automotive
- Racing components
Cast Iron Properties Table
| Element | Min % | Max % |
|---|---|---|
| C (Carbon) | 2.9 | 3.65 |
| Si (Silicon) | 1.8 | 2.9 |
| Mn (Manganese) | 0.4 | 0.7 |
| S (Sulfur) | 0 | 0.10 |
| P (Phosphorus) | 0 | 0.30 |
| Others | Traces | |
| Fe (Iron) | Balance to 100% | |
Note: Data subject to change even between different foundries
Iron-Carbon Phase Diagram
| Cast Iron (common name) | Hardness HB (30) | Tensile Strength Rm N/mm² |
Yield Strength Rp 0.2 |
Elongation A% | Structure | Graphite |
|---|---|---|---|---|---|---|
| GJL150 (G15) | 140-190 | 150 | - | 1-3 | Ferritic | Lamellar |
| GJL200 (G20) | 150-210 | 200 | - | 1-3 | Ferritic-Pearlitic | Lamellar |
| GJL250 (G25) | 170-240 | 250 | - | 1-3 | Pearlitic | Lamellar |
| GJL300 (G30) | 190-240 | 300 | - | 1-3 | Pearlitic | Lamellar |
Scroll right to see the entire table.
The data above should be considered approximate as they are only obtainable on standard test specimens automatically cast on a sand molding system. The values actually found on a casting strongly depend on the thickness of the element under consideration and the morphology of the casting (as these two aspects together determine the cooling curves and therefore the overall mechanical characteristics).
As an example, here’s how the tensile strength varies with thickness:
| Material Designation | Determining Wall Thickness [mm] | Prescribed Tensile Strength Rm (On specimen) [N/mm²] |
Prescribed Tensile Strength Rm (On test piece) [N/mm²] |
Expected Tensile Strength Rm (On test piece) [N/mm²] |
|---|---|---|---|---|
| EN-GJL-150 | 5 | 150 to 250 | - | 155 |
| 10 | - | 130 | ||
| 20 | 120 | 110 | ||
| 40 | 110 | 95 | ||
| 80 | 100 | 80 | ||
| EN-GJL-200 | 5 | 200 to 300 | - | 205 |
| 10 | 170 | 180 | ||
| 20 | 150 | 155 | ||
| 40 | 130 | 130 | ||
| 80 | 140 | 115 | ||
| EN-GJL-250 | 5 | 250 to 350 | - | 250 |
| 10 | 210 | 225 | ||
| 20 | 210 | 195 | ||
| 40 | 190 | 170 |
Scroll right to see the entire table.
Spheroidal Cast Iron Castings UNI EN 1563
| Cast Iron Type | Tensile Strength | 0.2% Proof Stress | Elongation | Brinell Hardness |
|---|---|---|---|---|
| Material Designation | Rm [N/mm²] min | Rp0.2 [N/mm²] min | A% min | HB |
| EN-GJS-400-18 | 400 | 250 | 18 | 130 to 175 |
| EN-GJS-400-15 | 400 | 250 | 15 | 135 to 180 |
| EN-GJS-450-10 | 450 | 310 | 10 | 160 to 210 |
| EN-GJS-500-7 | 500 | 320 | 7 | 170 to 230 |
| EN-GJS-600-3 | 600 | 370 | 3 | 190 to 270 |
Scroll right to see the entire table.
Cast Iron Castings UNI EN 1561
| Cast Iron (common name) of material |
Hardness HB (30) | Tensile Strength Rm N/mm² |
Yield Strength Rp 0.2 |
Elongation A% | Structure | Graphite |
|---|---|---|---|---|---|---|
| GJS400 (GS400) | 140-200 | 400 | 240 | 8-18 | Ferritic | Spheroidal |
Scroll right to see the entire table.
Types of Cast Iron
There are various types of cast iron, each with specific properties that make it more suitable for certain industrial uses. In prototyping and custom component production, it’s essential to choose the most suitable alloy based on mechanical strength, machinability, vibration absorption, and tensile behavior. Below is a list of the main cast irons and their essential technical characteristics.