UNS S32550 (Alloy 255) Stainless Steel

Duplex Stainless Steels

Overview Chemical Composition Mechanical Properties Physical Properties Other Properties

Property Overview

Density7.8g/cm³

Elastic Modulus200GPa

Tensile Strength860MPa

Yield Strength620MPa

Brinell Hardness260HB

Maximum Service Temperature1100°C

Weight Calculator

Chemical Composition

0 to 0.040%

24 to 27%

4.5 to 6.5%

2.9 to 3.9%

0 to 1.5%

0 to 1.0%

0.1 to 0.25%

0 to 0.040%

0 to 0.030%

1.5 to 2.5%

57.2 to 67%

Mechanical

Elastic (Young's, Tensile) Modulus

200 GPa

Elongation at Break

21 %

Fatigue Strength

400 MPa

Poisson's Ratio

0.27

Reduction in Area

57 %

Shear Modulus

80 GPa

Shear Strength

540 MPa

Tensile Strength: Ultimate (UTS)

860 MPa

Tensile Strength: Yield (Proof)

620 MPa

Hardness

Brinell Hardness

260

Rockwell C Hardness

Physical

Density

7.8 g/cm 3

Thermal

Latent Heat of Fusion

300 J/g

Maximum Temperature: Corrosion

450 °C

Maximum Temperature: Mechanical

1100 °C

Melting Completion (Liquidus)

1440 °C

Melting Onset (Solidus)

1390 °C

Specific Heat Capacity

480 J/kg-K

Thermal Conductivity

16 W/m-K

Thermal Diffusivity

4.4 mm 2 /s

Thermal Expansion

13 µm/m-K

Thermal Shock Resistance

23 points

Electrical

Electrical Conductivity: Equal Volume

2.2 % IACS

Electrical Conductivity: Equal Weight (Specific)

2.5 % IACS

Calculated

PREN (Pitting Resistance)

Resilience: Ultimate (Unit Rupture Work)

160 MJ/m 3

Resilience: Unit (Modulus of Resilience)

940 kJ/m 3

Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

25 points

Strength to Weight: Axial

31 points

Strength to Weight: Bending

26 points

Environmental

Base Metal Price

20 % relative

Embodied Carbon

3.8 kg CO 2 /kg material

Embodied Energy

53 MJ/kg

Embodied Energy

53 MJ/kg 23 x 10 3 BTU/lb

Embodied Water

180 L/kg

Embodied Water

180 L/kg 22 gal/lb

Registered Designations & Aliases

Alloy 255S32550UNS S32550 (Alloy 255) Stainless Steel

Standards

ASTM A182 ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service

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 A473 ASTM A473: Standard Specification for Stainless Steel Forgings

ASTM A473 ASTM A473: Standard Specification for Stainless Steel Forgings Duplex Stainless Steels, Iris Alvarez-Armas and Suzanne Degallaix-Moreuil (editors), 2009 Duplex Stainless Steels: Microstructure, Properties and Applications, Robert N. Gunn (editor), 1997 ASTM A479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications Welding Metallurgy and Weldability of Stainless Steels, John C. Lippold and Damian J. Kotecki, 2005 ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011 Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993

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

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