ASTM Grade HN (20Cr-25Ni, J94213) Cast Stainless Steel
ASTM grade HN steel is an austenitic stainless steel formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. HN is the ASTM designation for this material. J94213 is the UNS number. And 20Cr-25Ni is the common industry name.
It has a moderately low ductility among the cast austenitic stainless steels in the database.
The graph bars on the material properties cards below compare ASTM grade HN 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
140
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
9.0 %
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
500 MPa 72 x 103 psi
Thermal Properties
Latent Heat of Fusion
310 J/g
Maximum Temperature: Corrosion
420 °C 790 °F
Maximum Temperature: Mechanical
1080 °C 1970 °F
Melting Completion (Liquidus)
1400 °C 2550 °F
Melting Onset (Solidus)
1350 °C 2460 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
13 W/m-K 7.7 BTU/h-ft-°F
Thermal Expansion
16 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
26 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
4.6 kg CO2/kg material
Embodied Energy
66 MJ/kg 28 x 103 BTU/lb
Embodied Water
180 L/kg 22 gal/lb
Common Calculations
PREN (Pitting Resistance)
22
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
17 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
3.5 mm2/s
Thermal Shock Resistance
11 points
Alloy Composition
Among cast stainless steels, the composition of ASTM grade HN 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 | 44.9 to 57.8 | |
| Ni | 23 to 27 | |
| Cr | 19 to 23 | |
| Mn | 0 to 2.0 | |
| Si | 0 to 2.0 | |
| C | 0.2 to 0.5 | |
| Mo | 0 to 0.5 | |
| 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 A297: Standard Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for General Application
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
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015