Austempered Ductile Cast Iron

Austempered cast iron is a cast iron. It can have the highest tensile strength among the cast irons in the database.

The properties of austempered cast iron include eight common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare austempered cast iron to: cast irons (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

ASTM A897 Grade 1 (ASTM 130-90-09 or 900-650-09, ISO 900-8) Cast Iron ASTM A897 Grade 2 (ASTM 150-110-07 or 1050-750-07, ISO 1050-6) Cast Iron

ASTM A897 Grade 3 (ASTM 175-125-4 or 1200-850-04, ISO 1200-3, EN-JS 1120) Cast Iron ASTM A897 Grade 4 (ASTM 200-155-1 or 1400-1100-02, ISO 1400-1, EN-JS 1130) Cast Iron

ASTM A897 Grade 5 (ASTM 230-185-01 or 1600-1300-01) Cast Iron ASTM Grade 110-70-11 or 750-500-11 Cast Iron

ASTM Grade 125-80-10 or 850-550-10 (ISO 800-10, EN-JS 1100) Cast Iron ASTM Grade 150-100-7 or 1050-700-7 (ISO 1000-6, EN-JS 1110) Cast Iron

Mechanical Properties

Brinell Hardness

270 to 490

Elastic (Young's, Tensile) Modulus

180 GPa 26 x 10⁶ psi

Elongation at Break

1.1 to 13 %

Poisson's Ratio

0.29

Shear Modulus

62 to 69 GPa 9.0 to 10 x 10⁶ psi

Tensile Strength: Ultimate (UTS)

860 to 1800 MPa 120 to 260 x 10³ psi

Tensile Strength: Yield (Proof)

560 to 1460 MPa 81 to 210 x 10³ psi

Thermal Properties

Latent Heat of Fusion

280 J/g

Melting Completion (Liquidus)

1380 °C 2520 °F

Melting Onset (Solidus)

1340 °C 2450 °F

Specific Heat Capacity

490 J/kg-K 0.12 BTU/lb-°F

Thermal Conductivity

42 W/m-K 24 BTU/h-ft-°F

Thermal Expansion

13 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

2.9 % relative

Density

7.5 g/cm³ 470 lb/ft³

Embodied Carbon

1.8 kg CO₂/kg material

Embodied Energy

25 MJ/kg 11 x 10³ BTU/lb

Embodied Water

48 L/kg 5.7 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

19 to 95 MJ/m³

Resilience: Unit (Modulus of Resilience)

880 to 3970 kJ/m³

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

25 points

Strength to Weight: Axial

32 to 66 points

Strength to Weight: Bending

27 to 44 points

Thermal Diffusivity

11 mm²/s

Thermal Shock Resistance

25 to 53 points

Alloy Composition

Iron (Fe)Fe		89.6 to 94
Carbon (C)C		3.4 to 3.8
Silicon (Si)Si		2.3 to 2.7
Nickel (Ni)Ni		0 to 2.0
Copper (Cu)Cu		0 to 0.8
Manganese (Mn)Mn		0.3 to 0.4
Molybdenum (Mo)Mo		0 to 0.3
Chromium (Cr)Cr		0 to 0.1
Vanadium (V)V		0 to 0.1
Aluminum (Al)Al		0 to 0.050
Phosphorus (P)P		0 to 0.040
Magnesium (Mg)Mg		0 to 0.040
Selenium (Se)Se		0 to 0.030
Sulfur (S)S		0 to 0.020
Tin (Sn)Sn		0 to 0.020
Arsenic (As)As		0 to 0.020