Iron Casting / NOD
Nodularizers
FeSiMg based nodularizers that transform graphite into spheroidal form in ductile iron production.
Technical Specifications
Key Features
- Controlled magnesium content (5-6% Mg)
- Rare earth (RE) element addition
- Promotes spheroidal graphite formation
- High strength and elongation values
- Controlled and safe reaction
- Low slag formation
Applications
- Ductile iron (GGG/EN-GJS) production
- Automotive: crankshaft, connecting rod, suspension
- Pipes: pressurized water and sewage pipes
- Wind energy: turbine hub and housing
- General engineering: valve, pump, gearbox
Dimension Table
| Element | Min (%) | Max (%) | Typical (%) |
|---|---|---|---|
| Mg | 5.0 | 6.0 | 5.5 |
| Si | 44 | 48 | 46 |
| RE | 0.5 | 1.5 | 1.0 |
| Ca | 0.5 | 2.0 | 1.2 |
| Al | 0 | 1.0 | 0.5 |
| Fe | - | - | Balance |
Technical Notes
- 01Treatment temperature should be between 1450-1520°C.
- 02Mg recovery rate is typically 40-60%.
- 03Applied via sandwich or tundish method.
- 04RE content should be adjusted based on slag composition.
- 05Inoculation must be performed after treatment.
Other Types
What are iron casting materials?
Iron casting materials are the metallurgical additives foundries use to control the structure of liquid iron. There are two main groups: inoculants (FeSi75-based alloys containing Ca, Ba or Sr) trigger graphite nucleation, while nodularizers (FeSiMg) convert flake graphite to spheroidal graphite, enabling ductile iron (GJS) production.
How inoculation and Mg treatment work
Inoculation seeds the melt with graphite nucleation sites just before casting: it prevents carbide (white iron/chill) formation, gives a uniform graphite distribution and improves machinability. Typical addition is 0.1–0.4%; Ca-based inoculants are general purpose, Ba-bearing grades hold their effect longer (fading resistance) for heavy, slow-cooling castings, and Sr-bearing grades excel in thin-wall grey iron with low slag. Nodularization is the heart of ductile iron production: an FeSiMg alloy with 3–10% Mg (typical addition 1.0–1.5%) binds the sulphur and oxygen in the melt and forces graphite to solidify as spheres — yielding far higher tensile strength and ductility than grey iron. Because Mg treatment inevitably reduces nucleus count, inoculation always follows nodularization. These are the standard consumables of automotive, pipe and machine-body foundries.
Frequently Asked Questions
What does an inoculant do?+
It seeds liquid iron with graphite nucleation sites: prevents chill (carbide) formation, homogenizes graphite distribution and improves mechanical properties and machinability. Typical addition is 0.1–0.4%.
Ca vs Ba vs Sr inoculants — what is the difference?+
Ca-based is general purpose; Ba-bearing keeps its effect longer (heavy, slow-cooling castings); Sr-bearing gives strong chill prevention in thin sections with low slag formation.
How does an FeSiMg nodularizer work?+
Its magnesium (typically 3–10%) binds the sulphur and oxygen in the melt, so graphite solidifies as spheres instead of flakes. The result is ductile iron: high strength plus ductility.
Why is inoculation needed after Mg treatment?+
Mg treatment lowers the nucleation potential; post-treatment (or in-stream) inoculation raises the nodule count and eliminates carbide risk.
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