UNS S21800 (Alloy 218) Stainless Steel

Austenitic & General Stainless Steels

Overview Chemical Composition Mechanical Properties Physical Properties Other Properties

Property Overview

Density7.5g/cm³

Elastic Modulus190GPa

Tensile Strength740MPa

Yield Strength390MPa

Brinell Hardness210HB

Maximum Service Temperature900°C

Weight Calculator

Chemical Composition

0 to 0.1%

16 to 18%

8.0 to 9.0%

7.0 to 9.0%

3.5 to 4.5%

0.080 to 0.18%

0 to 0.060%

0 to 0.030%

59.1 to 65.4%

Mechanical

Elastic (Young's, Tensile) Modulus

190 GPa

Elongation at Break

40 %

Fatigue Strength

330 MPa

Poisson's Ratio

0.28

Reduction in Area

62 %

Shear Modulus

75 GPa

Shear Strength

510 MPa

Tensile Strength: Ultimate (UTS)

740 MPa

Tensile Strength: Yield (Proof)

390 MPa

Hardness

Brinell Hardness

210

Rockwell B Hardness

Physical

Density

7.5 g/cm 3

Thermal

Latent Heat of Fusion

340 J/g

Maximum Temperature: Corrosion

410 °C

Maximum Temperature: Mechanical

900 °C

Melting Completion (Liquidus)

1360 °C

Melting Onset (Solidus)

1310 °C

Specific Heat Capacity

500 J/kg-K

Thermal Expansion

16 µm/m-K

Thermal Shock Resistance

17 points

Calculated

PREN (Pitting Resistance)

Resilience: Ultimate (Unit Rupture Work)

250 MJ/m 3

Resilience: Unit (Modulus of Resilience)

390 kJ/m 3

Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

26 points

Strength to Weight: Axial

27 points

Strength to Weight: Bending

24 points

Environmental

Base Metal Price

15 % relative

Embodied Carbon

3.1 kg CO 2 /kg material

Embodied Energy

45 MJ/kg

Embodied Energy

45 MJ/kg 19 x 10 3 BTU/lb

Embodied Water

150 L/kg

Embodied Water

150 L/kg 18 gal/lb

Registered Designations & Aliases

Alloy 218S21800UNS S21800 (Alloy 218) Stainless Steel

Standards

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

ASTM A479 ASTM A479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels

ASTM A479 ASTM A479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications Welding Metallurgy of Stainless Steels, Erich Folkhard et al., 2012 ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels

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