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ACI-ASTM CE8MN (ASTM A890 Grade 2A, J93345) Cast Stainless Steel

ACI-ASTM CE8MN steel is a duplex stainless steel formulated for casting. Cited properties are appropriate for the normalized and tempered condition. CE8MN is the designation in both the ACI and ASTM systems for this material. ASTM A890 Grade 2A is the ASTM designation. And J93345 is the UNS number.

It has a moderately high embodied energy and a moderately high tensile strength among cast duplex stainless steels.

The graph bars on the material properties cards below compare ACI-ASTM CE8MN steel to: cast duplex stainless steels (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.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

200 GPa 30 x 106 psi

Elongation at Break

29 %

Fatigue Strength

370 MPa 54 x 103 psi

Poisson's Ratio

0.27

Shear Modulus

80 GPa 12 x 106 psi

Tensile Strength: Ultimate (UTS)

750 MPa 110 x 103 psi

Tensile Strength: Yield (Proof)

500 MPa 73 x 103 psi

Thermal Properties

Latent Heat of Fusion

300 J/g

Maximum Temperature: Corrosion

440 °C 830 °F

Maximum Temperature: Mechanical

1100 °C 2010 °F

Melting Completion (Liquidus)

1440 °C 2630 °F

Melting Onset (Solidus)

1400 °C 2550 °F

Specific Heat Capacity

480 J/kg-K 0.11 BTU/lb-°F

Thermal Conductivity

16 W/m-K 9.2 BTU/h-ft-°F

Thermal Expansion

13 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

2.2 % IACS

Electrical Conductivity: Equal Weight (Specific)

2.5 % IACS

Otherwise Unclassified Properties

Base Metal Price

21 % relative

Density

7.8 g/cm3 490 lb/ft3

Embodied Carbon

4.2 kg CO2/kg material

Embodied Energy

58 MJ/kg 25 x 103 BTU/lb

Embodied Water

180 L/kg 21 gal/lb

Common Calculations

PREN (Pitting Resistance)

40

Resilience: Ultimate (Unit Rupture Work)

190 MJ/m3

Resilience: Unit (Modulus of Resilience)

620 kJ/m3

Stiffness to Weight: Axial

15 points

Stiffness to Weight: Bending

25 points

Strength to Weight: Axial

27 points

Strength to Weight: Bending

23 points

Thermal Diffusivity

4.2 mm2/s

Thermal Shock Resistance

21 points

Alloy Composition

Among cast stainless steels, the composition of ACI-ASTM CE8MN steel is notable for containing comparatively high amounts of chromium (Cr) and molybdenum (Mo). Chromium is the defining alloying element of stainless steel. Higher chromium content imparts additional corrosion resistance. Molybdenum is used to facilitate tempering. In addition, it offers modest bonuses to a wide range of material properties.

Iron (Fe)Fe 56 to 66.4
Chromium (Cr)Cr 22.5 to 25.5
Nickel (Ni)Ni 8.0 to 11
Molybdenum (Mo)Mo 3.0 to 4.5
Silicon (Si)Si 0 to 1.5
Manganese (Mn)Mn 0 to 1.0
Nitrogen (N)N 0.1 to 0.3
Carbon (C)C 0 to 0.080
Phosphorus (P)P 0 to 0.040
Sulfur (S)S 0 to 0.040

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM A890: Standard Specification for Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Austenitic/Ferritic) for General Application

Duplex Stainless Steels, Iris Alvarez-Armas and Suzanne Degallaix-Moreuil (editors), 2009

Duplex Stainless Steels: Microstructure, Properties and Applications, Robert N. Gunn (editor), 1997

Corrosion of Stainless Steels, A. John Sedriks, 1996

ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994

Advances in Stainless Steels, Baldev Raj et al. (editors), 2010

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015