ACI-ASTM CA6N (J91650) Cast Stainless Steel
ACI-ASTM CA6N steel is a martensitic stainless steel formulated for casting. Cited properties are appropriate for the heat treated (HT) condition. CA6N is the designation in both the ACI and ASTM systems for this material. J91650 is the UNS number.
It has a fairly high tensile strength among the cast martensitic stainless steels in the database.
The graph bars on the material properties cards below compare ACI-ASTM CA6N steel to: cast martensitic 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
190 GPa 28 x 106 psi
Elongation at Break
17 %
Fatigue Strength
640 MPa 93 x 103 psi
Poisson's Ratio
0.28
Reduction in Area
57 %
Shear Modulus
75 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
1080 MPa 160 x 103 psi
Tensile Strength: Yield (Proof)
1060 MPa 150 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
390 °C 730 °F
Maximum Temperature: Mechanical
740 °C 1370 °F
Melting Completion (Liquidus)
1440 °C 2620 °F
Melting Onset (Solidus)
1400 °C 2550 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
23 W/m-K 13 BTU/h-ft-°F
Thermal Expansion
9.9 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.6 % IACS
Electrical Conductivity: Equal Weight (Specific)
3.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
11 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
2.5 kg CO2/kg material
Embodied Energy
35 MJ/kg 15 x 103 BTU/lb
Embodied Water
110 L/kg 13 gal/lb
Common Calculations
PREN (Pitting Resistance)
12
Resilience: Ultimate (Unit Rupture Work)
180 MJ/m3
Resilience: Unit (Modulus of Resilience)
2900 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
38 points
Strength to Weight: Bending
30 points
Thermal Diffusivity
6.1 mm2/s
Thermal Shock Resistance
40 points
Alloy Composition
Among cast stainless steels, the composition of ACI-ASTM CA6N steel is notable for containing a comparatively high amount of nickel (Ni). Nickel is primarily used to achieve a specific microstructure. In addition, it has a beneficial effect on mechanical properties and certain types of corrosion.
| Fe | 77.9 to 83.5 | |
| Cr | 10.5 to 12.5 | |
| Ni | 6.0 to 8.0 | |
| Si | 0 to 1.0 | |
| Mn | 0 to 0.5 | |
| C | 0 to 0.060 | |
| P | 0 to 0.020 | |
| S | 0 to 0.020 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A743: Standard Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application
Welding Metallurgy and Weldability of Stainless Steels, John C. Lippold and Damian J. Kotecki, 2005
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