ACI-ASTM CG6MMN (J93790) Cast Stainless Steel
ACI-ASTM CG6MMN steel is an austenitic stainless steel formulated for casting. Cited properties are appropriate for the heat treated (HT) condition. CG6MMN is the designation in both the ACI and ASTM systems for this material. J93790 is the UNS number.
It has a very high tensile strength among the cast austenitic stainless steels in the database.
The graph bars on the material properties cards below compare ACI-ASTM CG6MMN 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
190
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
34 %
Fatigue Strength
260 MPa 38 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
79 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
670 MPa 97 x 103 psi
Tensile Strength: Yield (Proof)
320 MPa 47 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
460 °C 860 °F
Maximum Temperature: Mechanical
1080 °C 1970 °F
Melting Completion (Liquidus)
1420 °C 2590 °F
Melting Onset (Solidus)
1380 °C 2510 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Expansion
17 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
22 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
4.8 kg CO2/kg material
Embodied Energy
68 MJ/kg 29 x 103 BTU/lb
Embodied Water
180 L/kg 22 gal/lb
Common Calculations
PREN (Pitting Resistance)
34
Resilience: Ultimate (Unit Rupture Work)
190 MJ/m3
Resilience: Unit (Modulus of Resilience)
260 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
24 points
Strength to Weight: Bending
22 points
Thermal Shock Resistance
14 points
Alloy Composition
Among cast stainless steels, the composition of ACI-ASTM CG6MMN steel is notable for including vanadium (V) and containing a comparatively high amount of manganese (Mn). Vanadium has a strong hardening effect, but this effect is particularly sensitive to the type of tempering. Manganese is used to improve ductility at elevated temperatures. It also permits a higher nitrogen content than would otherwise be possible.
| Fe | 51.9 to 62.1 | |
| Cr | 20.5 to 23.5 | |
| Ni | 11.5 to 13.5 | |
| Mn | 4.0 to 6.0 | |
| Mo | 1.5 to 3.0 | |
| Si | 0 to 1.0 | |
| N | 0.2 to 0.4 | |
| Nb | 0.1 to 0.3 | |
| V | 0.1 to 0.3 | |
| C | 0 to 0.060 | |
| P | 0 to 0.040 | |
| S | 0 to 0.030 |
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