ACI-ASTM CD3MWCuN (ASTM A890 Grade 6A, J93380) Cast Stainless Steel
ACI-ASTM CD3MWCuN steel is a duplex stainless steel formulated for casting. Cited properties are appropriate for the normalized and tempered condition. CD3MWCuN is the designation in both the ACI and ASTM systems for this material. ASTM A890 Grade 6A is the ASTM designation. And J93380 is the UNS number.
It has a fairly high base cost among cast duplex stainless steels. In addition, it has a fairly high tensile strength and a moderately high embodied energy.
The graph bars on the material properties cards below compare ACI-ASTM CD3MWCuN 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)
790 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
450 °C 840 °F
Maximum Temperature: Mechanical
1100 °C 2010 °F
Melting Completion (Liquidus)
1460 °C 2650 °F
Melting Onset (Solidus)
1410 °C 2570 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
16 W/m-K 9.1 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
22 % relative
Density
7.9 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 22 gal/lb
Common Calculations
PREN (Pitting Resistance)
42
Resilience: Ultimate (Unit Rupture Work)
200 MJ/m3
Resilience: Unit (Modulus of Resilience)
620 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
28 points
Strength to Weight: Bending
24 points
Thermal Diffusivity
4.2 mm2/s
Thermal Shock Resistance
22 points
Alloy Composition
Among cast stainless steels, the composition of ACI-ASTM CD3MWCuN steel is notable for including tungsten (W) and copper (Cu). Tungsten interacts with other alloying elements to a greater extent than usual, which makes it hard to broadly characterize its effects. Copper is primarily used to improve resistance to acids.
| Fe | 56.6 to 65.3 | |
| Cr | 24 to 26 | |
| Ni | 6.5 to 8.5 | |
| Mo | 3.0 to 4.0 | |
| Mn | 0 to 1.5 | |
| W | 0.5 to 1.0 | |
| Cu | 0.5 to 1.0 | |
| Si | 0 to 1.0 | |
| N | 0.2 to 0.3 | |
| C | 0 to 0.030 | |
| P | 0 to 0.030 | |
| S | 0 to 0.025 |
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
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