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Why Convert To Ductile Iron? Designers are converting steel castings, forgings, and fabrications to Ductile Iron castings to gain the following benefits:
Many steel castings, forgings, and fabrications can be converted to Ductile Iron castings at lower cost with equal or superior performance. Talk To A Ductile Iron Foundry Representative Today! |
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Designing Effective Castings |
Learn More About |
Effective castings are a product of Designers and Foundry Engineers working together.
Talk To A Ductile Iron Foundry Representative Today! |
A free, 40 page booklet "A Design Engineers Digest of Ductile Iron" is currently available, as well as two new technical publications, "Conversions to Ductile Iron" and "The Ductile Iron Data Book". To obtain these books and a list of Ductile Iron Foundries, or to discuss how you can take advantage of Ductile Iron castings, contact the Ductile Iron Group, or any of its member companies.
The Ductile Iron Marketing Group The Ductile Iron Marketing Group is a non-profit organization dedicated to increasing the understanding of the technical and economic advantages of Ductile Iron castings. The Members of the Ductile Iron Marketing Group are:
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Physical Properties of Ductile Iron and Alternative Materials |
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Property |
Unit |
Ductile Iron |
0.3% C |
Malleable Iron |
Gray |
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120-90-02 |
100-70-03 |
80-55-06 |
65-45-12 |
60-40-18 |
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| Solidus Temperature |
°F |
2,100 |
2,100 |
2,100 |
2,100 |
2,100 |
2,650 |
2,050 |
2,140 |
| Specific Gravity |
lb/in³ |
0.25 |
0.25 |
0.25 |
0.25 |
0.25 |
0.283 |
0.265 |
0.25 |
| Mean Linear Thermal Expansion |
°F-¹ |
6.0 |
6.0 |
6.0 |
6.0 |
6.0 |
7.0 |
6.7 |
5.8 |
| Vibration Damping |
- |
Good |
Good |
Good |
Good |
Very Good |
Poor |
Good |
Excellent |
| Heat of Fusion |
BTU/lb |
55 |
55 |
55 |
55 |
55 |
108 |
55 |
55 |
| Specific Heat |
BTU/lb/°F |
0.15 |
0.15 |
0.14 |
0.13 |
0.13 |
0.11 |
0.12 |
0.13 |
| Thermal Conductivity (near room temperature) |
Cal/cmsec °C |
0.06 |
0.06 |
0.08 |
0.09 |
0.10 |
0.11 |
0.14 |
0.11 |
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Magnetic Properties |
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| Maximum Permeability at 5,000 Gauss |
Oersted |
290 |
290 |
570 |
2,100 |
2,100 |
- |
2,350 |
800 |
| Saturation Induction at 10,000 Oersted |
Gauss |
- |
- |
17,600 |
18,000 |
18,000 |
- |
- |
16,000 |
| Hysteresis Loss |
Erg/cm³/cycle |
- |
30 |
30 |
5 |
5 |
100 |
20 |
30 |
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Mechanical Properties |
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| Proof Stress |
psi |
(0.62 to 0.75) x Ultimate Tensile Strength |
30,500 |
(0.65-0.8) |
- |
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| Modulus of Elasticity in Tension |
psi x 10 to the 6th |
25.7 |
25.7 |
25.2 |
23.8 |
23.8 |
30.5 |
25 |
18.3 |
| Torsional Strength |
psi |
108,000 |
90,000 |
72,000 |
58,000 |
50,000 |
- |
34,000 |
60,000 |
| Modulus of Rigidity |
psi x 10 to the 6th |
9.6 |
9.6 |
9.6 |
9.3 |
9.1 |
11.4 |
11 |
7.1 |
* A medium-high strength gray iron was selected for comparison purposes.
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Short Summary of Ductile Iron Specifications |
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Specifying Body |
Spec. No. |
Class or Grade |
Min. Tensile psi |
Min. |
% Elongation |
Heat Treatment |
Other Requirements |
Uses |
Typical Applications |
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ASTM |
A536-80 |
60-40-18 |
60,000 |
40,000 |
18 |
May be Annealed |
In all grades in this specification chemical composition is subordinate to mechanical properties. However, the content of any element may be specified by mutual agreement. | For maximum shock resistant parts to be used at sub-zero temperatures. | Pressure-containing castings such as valve and pump bodies. |
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ASTM |
A536-80 |
65-45-12 |
65,000 |
45,000 |
12 |
- |
Most widely used grade for normal service. | Machinery castings subject to shock and fatigue loading. | |
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ASTM |
A536-80 |
80-50-06 |
80,000 |
55,000 |
6 |
- |
Suitable for flame and induction hardening. | Crankshafts, gears and rollers. | |
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ASTM |
A536-80 |
100-70-03 |
100,000 |
70,000 |
3 |
Usually Normalized |
Best combination of strength, wear resistance and response to surface hardening. | High strength gears, automotive and machine components. | |
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ASTM |
A536-80 |
120-90-02 |
120,000 |
90,000 |
2 |
Quenched and Tempered |
Maximum strength and wear resistance. | Pinions, gears, rollers and slides. | |
| Short Summary of Austenitic Ductile Iron Specifications | |||||||||||||||
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Specifying Body |
Spec. No. |
Class or Grade |
Min. Tensile psi |
Min. Yield psi |
% Elongation |
Heat Treatment |
Chemical Analysis and Hardness |
Typical Applications |
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% T.C. |
% |
% |
% |
% |
% |
BHN |
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| ASTM | A439-84 |
D-2 |
58,000 |
30,000 |
8 |
Min. |
1.50 |
0.70 |
18.00 |
1.75 |
139 |
Valve stem bushings, valve and pump bodies in petroleum, salt water and caustic service, manifolds, turbocharger housings, air compressor parts. | |||
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Max. |
3.00 |
3.00 |
1.25 |
0.08 |
22.00 |
2.75 |
202 |
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D-2B |
58,000 |
30,000 |
7 |
Min. |
1.50 |
0.70 |
18.00 |
2.75 |
148 |
Turbocharger housings, rolls. | |||||
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Max. |
3.00 |
3.00 |
1.25 |
0.08 |
22.00 |
4.00 |
211 |
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D2-C |
58,000 |
28,000 |
20 |
Min. |
1.00 | 1.80 | 21.00 |
121 |
Electrode guide rings, steam turbine dubbing rings. | ||||||
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Max. |
2.90 |
3.00 |
2.40 |
0.08 |
24.00 |
0.50 |
171 |
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D-3 |
55,000 |
30,000 |
6 |
Min. |
1.00 |
28.00 |
2.50 |
139 |
Turbocharger nozzles and housings, steam turbine diaphragms, gas compressor diffusers. | ||||||
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Max. |
2.60 |
2.80 |
1.00 |
0.08 |
32.00 |
3.50 |
202 |
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D-3A |
55,000 |
30,000 |
10 |
Min. |
1.00 |
28.00 |
1.00 |
131 |
High temperature bearing rings requiring resistance to galling. | ||||||
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Max. |
2.60 |
2.80 |
1.00 |
0.08 |
32.00 |
1.50 |
193 |
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D-4 |
60,000 |
Min. |
5.00 |
28.00 |
4.50 |
202 |
Diesel engine manifolds, manifold joints. | ||||||||
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Max. |
.60 |
6.00 |
1.00 |
0.08 |
32.00 |
5.50 |
273 |
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D-5 |
55,000 |
30,000 |
20 |
Min. |
1.00 |
34.00 |
131 |
Guidance system housings, gas turbine shroud rings, glass rolls. | |||||||
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Max. |
2.40 |
2.80 |
1.00 |
0.08 |
36.00 |
0.10 |
185 |
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D-5B |
55,000 |
30,000 |
6 |
Min. |
1.00 |
34.00 |
2.00 |
139 |
Optical system mirrors and parts for dimensional stability, stators for compressors. | ||||||
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Max. |
2.40 |
2.80 |
1.00 |
0.08 |
36.00 |
3.00 |
193 |
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D-5S |
65,000 |
30,000 |
10 |
Min. |
4.90 |
34.00 |
1.75 |
131 |
Manifolds, turbine housings, turbochargers where high temperatures and severe thermal cycling occur. | ||||||
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Max. |
2.30 |
5.50 |
1.00 |
0.08 |
37.00 |
2.25 |
193 |
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ASTM |
A571-71 (1976) |
D-2M |
65,000 |
30,000 |
30 |
Annealed |
Min. |
2.20 |
1.50 |
3.75 |
21.00 |
121 |
Compressors, expanders pumps and other pressure- containing parts requiring a stable austenitic matrix at minus 423F (-234C) |
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ASME |
SA571 |
Max. |
2.70 |
2.50 |
4.50 |
0.08 |
24.00 |
0.20 |
171 |
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| Short Summary of ASTM Specification A897-90 / A897M-90 For Austempered Ductile Iron |
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| Grade | Min. Tensile Strength |
Min. Yield Strength |
Elongation Percent | Impact Energy* | Hardness BHN** | |||
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MPa |
Ksi |
MPa |
Ksi |
Joules |
Ft-lb |
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125/80/10 |
125 |
80 |
10 |
75 |
269-321 |
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850/550/10 |
850 |
550 |
10 |
100 |
269-321 |
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150/100/7 |
150 |
100 |
7 |
60 |
302-363 |
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1050/700/7 |
1050 |
700 |
7 |
80 |
302-363 |
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175/125/4 |
175 |
125 |
4 |
45 |
341-444 |
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1200/850/4 |
1200 |
850 |
4 |
60 |
341-444 |
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200/155/1 |
200 |
155 |
1 |
25 |
388-477 |
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1400/1100/1 |
1400 |
1100 |
1 |
35 |
388-477 |
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230/185/- |
230 |
185 |
*** |
*** |
444-555 |
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1600/1300/- |
1600 |
1300 |
*** |
*** |
444-555 |
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* Values obtained using unnotched Charpy bars tested at 72° F (2° C). The values in the table are the
average of the three highest of four tested samples.
** Hardness is not a mandatory specification and is shown for information only.
*** Elongation and impact specifications are not required.