MakeItFrom.com
Menu (ESC)

ACI-ASTM CB6 (J91804) Cast Stainless Steel

ACI-ASTM CB6 steel is a martensitic stainless steel formulated for casting. Cited properties are appropriate for the heat treated (HT) condition. CB6 is the designation in both the ACI and ASTM systems for this material. J91804 is the UNS number.

It has a moderately low electrical conductivity among cast martensitic stainless steels. In addition, it has a moderately low thermal conductivity and a fairly high ductility.

The graph bars on the material properties cards below compare ACI-ASTM CB6 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

200 GPa 29 x 106 psi

Elongation at Break

18 %

Fatigue Strength

410 MPa 59 x 103 psi

Poisson's Ratio

0.28

Reduction in Area

40 %

Shear Modulus

77 GPa 11 x 106 psi

Tensile Strength: Ultimate (UTS)

880 MPa 130 x 103 psi

Tensile Strength: Yield (Proof)

660 MPa 96 x 103 psi

Thermal Properties

Latent Heat of Fusion

280 J/g

Maximum Temperature: Corrosion

410 °C 770 °F

Maximum Temperature: Mechanical

870 °C 1600 °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

17 W/m-K 9.8 BTU/h-ft-°F

Thermal Expansion

10 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

2.2 % IACS

Electrical Conductivity: Equal Weight (Specific)

2.6 % IACS

Otherwise Unclassified Properties

Base Metal Price

12 % relative

Density

7.8 g/cm3 490 lb/ft3

Embodied Carbon

2.5 kg CO2/kg material

Embodied Energy

36 MJ/kg 15 x 103 BTU/lb

Embodied Water

130 L/kg 15 gal/lb

Common Calculations

PREN (Pitting Resistance)

17

Resilience: Ultimate (Unit Rupture Work)

150 MJ/m3

Resilience: Unit (Modulus of Resilience)

1110 kJ/m3

Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

25 points

Strength to Weight: Axial

32 points

Strength to Weight: Bending

26 points

Thermal Diffusivity

4.6 mm2/s

Thermal Shock Resistance

31 points

Alloy Composition

Among cast stainless steels, the composition of ACI-ASTM CB6 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.

Iron (Fe) 74.4 to 81
Chromium (Cr) 15.5 to 17.5
Nickel (Ni) 3.5 to 5.5
Manganese (Mn) 0 to 1.0
Silicon (Si) 0 to 1.0
Molybdenum (Mo) 0 to 0.5
Carbon (C) 0 to 0.060
Phosphorus (P) 0 to 0.040
Sulfur (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 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