Solid Solution Ductile Iron
on June 12, 2019Related standards: ISO 1083/JS/500-10
Conventional ductile iron contains a mix of pearlite and ferrite in the matrix surrounding the nodules. This mix, depending on different cooling rates throughout the casting, can cause large ranges in mechanical properties like hardness.
In solid solution ferritic ductile iron, hardness is much more uniform. This also increases the elongation percentage, as well as impact properties.
Composition
The chemical make-up of solid solution ferritic ductile iron is not specified by the International Standard, and can change due to the method of manufacturing and charge materials. It is important to use high quality materials and monitor the chemical composition to achieve the desired tensile strength, elongation, and hardness values.
Example of Chemical Composition
Note: The focus with solid solution ductile iron is on a high silicon percentage.
| C% approx |
Si% approx |
Mn% max |
P% max |
S% max |
Mg% approx |
Cu% max |
| 3.3 | 3.7 | 0.3 | 0.05 | 0.02 | 0.04 | 0.1 |
Physical and Mechanical Properties
| Yield Strength (MPa) | 360 |
| Tensile Strength (MPa) | 500 |
| % Elongation Min | 10% |
| Hardness (BHW) | 185-210 |
| Impact Energy from -20 to 0C (J) | 12-20 |
Impact Properties
Impact strength is the ability to resist high loading, which is related to better product performance and a longer service life. Due to the ferritic microstructure in the solid solution ductile iron, the impact properties are much better than the traditional mixed pearlite and ferrite microstructures. The ISO 1083 standard specifies charpy values for low temperature applications.
Resource: To learn more about ductile iron impact values read “Impact Values of Ductile Iron for Design Engineers.”
Machinability
Compared to traditional ductile iron, the solid solution ferritic ductile iron has a much smaller range of hardness deviation. This allows for enhanced machinability, but maintains the same average hardness value.
Read “Ductile Iron Machining Advantages” for insight and tips into machining ductile iron, ASTM A536.
Applications
Solid solution ferritic ductile iron is ideal for applications where machinability, impact resistance and strength are required.
- Brakes
- Gear boxes
- Frames
- Oil and gas parts
- Pumping parts
- Compressor parts
- Mining parts,
- Wind energy and other applications
To learn more about ductile iron, check out our ductile iron webpage.
