ACI-ASTM CG12 (J93001) Cast Stainless Steel
ACI-ASTM CG12 steel is an austenitic stainless steel formulated for casting. Cited properties are appropriate for the heat treated (HT) condition. CG12 is the designation in both the ACI and ASTM systems for this material. J93001 is the UNS number.
It has a moderately high ductility among cast austenitic stainless steels. In addition, it has a moderately low base cost and a moderately low embodied energy.
The graph bars on the material properties cards below compare ACI-ASTM CG12 steel to: cast austenitic 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
Brinell Hardness
160
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
40 %
Fatigue Strength
190 MPa 27 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
78 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
550 MPa 80 x 103 psi
Tensile Strength: Yield (Proof)
220 MPa 32 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
430 °C 810 °F
Maximum Temperature: Mechanical
1040 °C 1900 °F
Melting Completion (Liquidus)
1410 °C 2580 °F
Melting Onset (Solidus)
1370 °C 2500 °F
Specific Heat Capacity
480 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
15 W/m-K 8.6 BTU/h-ft-°F
Thermal Expansion
16 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
18 % relative
Density
7.8 g/cm3 480 lb/ft3
Embodied Carbon
3.3 kg CO2/kg material
Embodied Energy
48 MJ/kg 20 x 103 BTU/lb
Embodied Water
160 L/kg 19 gal/lb
Common Calculations
PREN (Pitting Resistance)
22
Resilience: Ultimate (Unit Rupture Work)
180 MJ/m3
Resilience: Unit (Modulus of Resilience)
120 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
20 points
Strength to Weight: Bending
19 points
Thermal Diffusivity
4.0 mm2/s
Thermal Shock Resistance
12 points
Alloy Composition
Among cast stainless steels, the composition of ACI-ASTM CG12 steel is notable for containing comparatively high amounts of chromium (Cr) and nickel (Ni). Chromium is the defining alloying element of stainless steel. Higher chromium content imparts additional corrosion resistance. 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 | 60.3 to 70 | |
| Cr | 20 to 23 | |
| Ni | 10 to 13 | |
| Si | 0 to 2.0 | |
| Mn | 0 to 1.5 | |
| C | 0 to 0.12 | |
| 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 A743: Standard Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application
Welding Metallurgy of Stainless Steels, Erich Folkhard et al., 2012
Corrosion of Austenitic Stainless Steels: Mechanism, Mitigation and Monitoring, H. S. Khatak and B. Raj (editors), 2002
Austenitic Stainless Steels: Microstructure and Mechanical Properties, P. Marshall, 1984
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010