ACI-ASTM CD6MN (ASTM A890 Grade 3A, J93371) Cast Stainless Steel
ACI-ASTM CD6MN steel is a duplex stainless steel formulated for casting. Cited properties are appropriate for the normalized and tempered condition. CD6MN is the designation in both the ACI and ASTM systems for this material. ASTM A890 Grade 3A is the ASTM designation. And J93371 is the UNS number.
The graph bars on the material properties cards below compare ACI-ASTM CD6MN 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
28 %
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)
730 MPa 110 x 103 psi
Tensile Strength: Yield (Proof)
510 MPa 74 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
450 °C 840 °F
Maximum Temperature: Mechanical
1100 °C 2010 °F
Melting Completion (Liquidus)
1440 °C 2620 °F
Melting Onset (Solidus)
1390 °C 2540 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
16 W/m-K 9.4 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.1 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
17 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
3.4 kg CO2/kg material
Embodied Energy
48 MJ/kg 21 x 103 BTU/lb
Embodied Water
170 L/kg 20 gal/lb
Common Calculations
PREN (Pitting Resistance)
36
Resilience: Ultimate (Unit Rupture Work)
180 MJ/m3
Resilience: Unit (Modulus of Resilience)
650 kJ/m3
Stiffness to Weight: Axial
15 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
26 points
Strength to Weight: Bending
23 points
Thermal Diffusivity
4.4 mm2/s
Thermal Shock Resistance
20 points
Alloy Composition
Among cast stainless steels, the composition of ACI-ASTM CD6MN steel is notable for containing a comparatively high amount of chromium (Cr) and including nitrogen (N). Chromium is the defining alloying element of stainless steel. Higher chromium content imparts additional corrosion resistance. Nitrogen has a substantial strengthening effect, but has a complex (frequently negative) relationship with corrosion resistance.
| Fe | 62.1 to 70.1 | |
| Cr | 24 to 27 | |
| Ni | 4.0 to 6.0 | |
| Mo | 1.8 to 2.5 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 1.0 | |
| N | 0.15 to 0.25 | |
| C | 0 to 0.060 | |
| P | 0 to 0.040 | |
| 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
Welding Metallurgy of Stainless Steels, Erich Folkhard et al., 2012
Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993
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