ConTINUOUS CAST
GREY IRON & DUCTILE IRON
Continuous cast Gray Irons contain flake graphite in matrix structures that range from all pearlite to pearlite plus ferrite. The matrix structure will influence machinability, strength, hardness and wear characteristics. In general, a fully pearlitic matrix will have the best mechanical properties and will be readily machinable. Bars containing ferrite in the matrix will be easier to machine but will be lower in strength and wear resistance.
Continuous cast Ductile Irons contain nodular graphite in a matrix of pearlite and ferrite. The spheroidal shaped graphite maximizes the strength in cast iron. The ratio of ferrite to pearlite in the matrix varies in each of the three grades in order to produce the required tensile and yield strengths and elongation properties. The nodular graphite provides the same free machining benefits as lead (steel) without the machining and waste disposal problems.
OD Dimension Tolerance OD tolerance is on the plus side...OD size ordered will machine to the OD size ordered.
| AVAILABLE SIZES | |
Round | Thru 20" |
Tube | .500" ID x 3" OD thru 7" ID x 9" OD |
Rectangles | 1" x 2" thru 7.500" x 20.500" |
Squares | 3" thru 10" |
| MATERIAL SELECTION GUIDE | |||
| Grade | Characteristics | Applications | Examples |
| G1A Gray Iron | Pearlite & ferrite matrix, flake graphite | Moderate strength, increased machinability, excellent damping | Pump gears, air compressors, screws |
| G2 Class 40 Gray Iron | Pearlite matrix, flake graphite | Moderate strength, good wear as-cast, excellent damping | Balance shaft gears, lightly loaded drive gears, large printing press gears |
| G2 Heat Treated Gray Iron | Martensitic matrix, flake graphite | Best wear in a non-alloyed ferrous metal, moderate strength, tooth sections >.250", good damping | Same as above, better wear resistance |
| G2 Alloyed Gray iron | Pearlite or martensitic matrix, alloyed carbides, flake graphite | Improved wear over class 40 grade or quench and tempered class 40 grade; increased wear resistance with higher chrome levels. | Most automotive gray iron gears |
| 65-45-1 Ductile Iron | Ferrite with 20% pearlite matrix , nodular graphite | Good machinability, size control after heat treatment | Balance shaft gears, accessory gears, rotary screw compressor gears, non contacting pump gears |
| 80-55-06 Ductile Iron | Pearlite with 15% ferrite, nodular graphite | Higher strength, higher hardness, increased wear; good heat treat response when flame or induction hardening | Balance shaft gears, printing press gears, rotary screw compressors, pump gears |
| 100-70-02 Ductile Iron | Ferrite with 50% pearlite matrix, nodular graphite | Good wear resistance without heat treating | Balance shaft gears, printing press gears, rotary screw compressors, pump gears |
| Austempered Ductile Iron | Ausferrite matrix with nodular graphite | Tensile, impact fatigue strengths, wear resistance | Highly loaded gears, transmission gears, speed reducers |
| GRAY IRON PROPERTIES | |||
Type | G1A | G1 | G2 Class 40 |
| Tensile strength (psi) | 25,000 | 30,000 | 40,000 |
| Compressive strength (psi) | n/a | 120,000 | 150,000 |
| Heat-treat response | n/a | Rc 40 min. | Rc 50 min. |
| Hardness (BHN) | n/a | n/a | n/a |
| 3/4" - 1-1/2" | 159-229 | 179-235 | 229-285 |
| 1-1/2" - 3" | 156-201 | 163-229 | 207-277 |
| 3" - 6" | 143-201 | 151-229 | 197-268 |
| 6" - 20" | 143-201 | 143-201 | 183-269 |
| Microstructure | Highly ferritic | Partially ferritic | Highly pearlitic |
