Duplex Steel S31803 / S32205 is a nitrogen-enhanced duplex stainless steel that offers a balanced microstructure of austenite and ferrite, providing an excellent combination of high strength, toughness, and superior corrosion resistance. It delivers significantly higher yield strength than conventional austenitic stainless steels while maintaining good weldability and resistance to stress corrosion cracking, pitting, and crevice corrosion. Duplex Steel S31803 / S32205 is widely used in oil and gas pipelines, chemical processing equipment, heat exchangers, pressure vessels, and marine applications where durability, strength, and long service life are essential. Its cost efficiency and performance make it a preferred choice for demanding industrial environments.
CHEMICAL COMPOSITION OF DUPLEX STEEL S31803 / S32205 ROUND BAR
Grade
C %
Mn %
Si %
P %
S %
Cr %
Ni %
Mo %
N %
S31803
0.03 max
2.0 max
1.0 max
0.03 max
0.02 max
21.0 – 23.0
4.5 – 6.5
2.5 – 3.5
0.08 – 0.20
S32205
0.03 max
2.0 max
1.0 max
0.03 max
0.02 max
22.0 – 23.0
4.5 – 6.5
3.0 – 3.5
0.14 – 0.20
MECHANICAL PROPERTIES OF DUPLEX STEEL S31803 / S32205 ROUND BAR
Property
Value
Tensile Strength
620 MPa (min)
Yield Strength (0.2% Offset)
450 MPa (min)
Elongation
25 % (min)
Density
7.8 g/cm³
Elastic Modulus
200 GPa
PHYSICAL PROPERTIES OF DUPLEX STEEL S31803 / S32205 ROUND BAR
Property
Value
Density
0.286 lb/in³
Thermal Conductivity
9.3 BTU/hr-ft-°F at 200°F
Coefficient of Thermal Expansion
9.2 × 10⁻⁶ /°F (68–212°F)
Specific Heat
0.12 BTU/lb-°F
Modulus of Elasticity
28 × 10⁶ psi (E)
💡 Practical Difference in Use
Use Duplex Steel S31803 / S32205 Round Bars when: high strength, excellent corrosion resistance, and resistance to stress corrosion cracking are required. Duplex S31803 / S32205 combines austenitic and ferritic microstructures, offering nearly double the yield strength of austenitic stainless steels along with superior resistance to pitting and crevice corrosion.
→ Example: oil & gas pipelines, marine shafts, heat exchangers, pressure vessels, chemical processing equipment, and structural components.
Bright Finished / Machined Duplex Steel S31803 / S32205 Round Bars when: tight dimensional tolerances, smooth surface finish, and consistent mechanical performance are required. Bright drawn or ground bars improve machinability and surface quality while retaining excellent corrosion resistance.
→ Example: precision shafts, pump components, valve parts, offshore fasteners, CNC machined components, and structural assemblies.
Applications of Duplex Steel S31803 / S32205 Round Bars
Duplex Steel S31803 / S32205 round bars are extensively used in industries where strength, corrosion resistance, and long service life are critical.
