MakeItFrom.com
Menu (ESC)

UNS N08800 (Alloy 800) Stainless Steel

N08800 stainless steel is a superaustenitic (highly alloyed) stainless steel formulated for primary forming into wrought products. N08800 is the UNS number for this material. Alloy 800 is the common industry name. Additionally, the British Standard (BS) designation is NA15. And the AFNOR (French) designation is 25NC35-20.

This material is well established: the Further Reading section below cites a number of published standards, and that list is not necessarily exhaustive.

It can have the highest tensile strength among wrought superaustenitic stainless steels. In addition, it can have the lowest ductility and has a moderately low base cost.

The properties of N08800 stainless steel include four common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare N08800 stainless steel to: wrought superaustenitic 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

4.5 to 34 %

Fatigue Strength

150 to 390 MPa 22 to 56 x 103 psi

Poisson's Ratio

0.28

Shear Modulus

77 GPa 11 x 106 psi

Shear Strength

340 to 580 MPa 49 to 84 x 103 psi

Tensile Strength: Ultimate (UTS)

500 to 1000 MPa 73 to 150 x 103 psi

Tensile Strength: Yield (Proof)

190 to 830 MPa 28 to 120 x 103 psi

Thermal Properties

Curie Temperature

-120 °C -180 °F

Latent Heat of Fusion

300 J/g

Maximum Temperature: Corrosion

490 °C 920 °F

Maximum Temperature: Mechanical

1100 °C 2010 °F

Melting Completion (Liquidus)

1390 °C 2530 °F

Melting Onset (Solidus)

1360 °C 2470 °F

Specific Heat Capacity

480 J/kg-K 0.11 BTU/lb-°F

Thermal Conductivity

12 W/m-K 6.6 BTU/h-ft-°F

Thermal Expansion

14 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

1.7 % IACS

Electrical Conductivity: Equal Weight (Specific)

1.9 % IACS

Otherwise Unclassified Properties

Base Metal Price

30 % relative

Density

8.0 g/cm3 500 lb/ft3

Embodied Carbon

5.3 kg CO2/kg material

Embodied Energy

76 MJ/kg 33 x 103 BTU/lb

Embodied Water

200 L/kg 24 gal/lb

Common Calculations

PREN (Pitting Resistance)

21

Resilience: Ultimate (Unit Rupture Work)

42 to 160 MJ/m3

Resilience: Unit (Modulus of Resilience)

96 to 1740 kJ/m3

Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

24 points

Strength to Weight: Axial

18 to 35 points

Strength to Weight: Bending

18 to 28 points

Thermal Diffusivity

3.0 mm2/s

Thermal Shock Resistance

13 to 25 points

Alloy Composition

Among wrought stainless steels, the composition of N08800 stainless steel is notable for including aluminum (Al) and titanium (Ti). Aluminum is used to improve oxidation resistance. It can also enhance the effects of heat treatment. Titanium is used to broadly improve mechanical properties.

Iron (Fe) 39.5 to 50.7
Nickel (Ni) 30 to 35
Chromium (Cr) 19 to 23
Manganese (Mn) 0 to 1.5
Silicon (Si) 0 to 1.0
Aluminum (Al) 0.15 to 0.6
Titanium (Ti) 0.15 to 0.6
Copper (Cu) 0 to 0.75
Carbon (C) 0 to 0.1
Phosphorus (P) 0 to 0.045
Sulfur (S) 0 to 0.015

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM B514: Standard Specification for Welded Nickel-Iron-Chromium Alloy Pipe

ASTM B515: Standard Specification for Welded UNS N08120, UNS N08800, UNS N08810, and UNS N08811 Alloy Tubes

ASTM B409: Standard Specification for Nickel-Iron-Chromium Alloy Plate, Sheet, and Strip

ASTM B407: Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube

ASTM B564: Standard Specification for Nickel Alloy Forgings

EN 10095: Heat resisting steels and nickel alloys

ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys, Joseph R. Davis (editor), 2000

Nickel Alloys, Ulrich Heubner (editor), 1998

ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications

ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels