Duplex 31803 (1.4462/F51)

Duplex 31803 combines high yield strength with excellent fatigue and impact resistance, making it suitable for structural components exposed to mechanical stress and corrosive attack.

Typical Mechanical Properties (Room Temperature):

Tensile Strength: 700–950 MPa – Withstands high mechanical load without failure.

Yield Strength (0.2%): 450–600 MPa – Over twice the strength of many austenitic stainless steels.

Elongation: 25–35% – Ensures good ductility during forming and fabrication.

Hardness (Vickers): 260–320 HV – Supports wear resistance in demanding conditions.

Modulus of Elasticity: 200 GPa – High stiffness under stress.

Poisson’s Ratio: 0.3 – Maintains dimensional integrity under pressure.

This combination of strength and toughness makes Duplex 31803 ideal for use in pressurised systems, load-bearing frames, and industrial machinery.

Duplex 31803’s dual-phase structure enhances thermal stability, making it reliable under fluctuating temperature and mechanical loads.

Typical Physical Properties:

Density: 7.8 g/cm³ – Provides strength without unnecessary weight.

Thermal Conductivity (20 °C): ~19 W/m·K – Suitable for heat transfer applications.

Specific Heat Capacity: ~500 J/kg·K – Stable under thermal cycling.

Modulus of Elasticity: 200 GPa – Maintains rigidity under dynamic load.

Electrical Resistivity: ~0.8 µΩ·m – Reflects semi-conductive properties.

Magnetic: Yes – Due to ferritic content, the alloy exhibits magnetism.

These properties support safe, consistent performance in systems exposed to heat, pressure, and variable operating conditions.

Several duplex and super duplex alternatives exist, offering modified corrosion resistance or mechanical performance depending on application needs.

Notable Variants:

Duplex 2205: The most widely used duplex stainless steel, often used interchangeably with 31803. Offers similar corrosion resistance and strength.

Super Duplex Grades (e.g., 32750, 32760): Enhanced with higher chromium, molybdenum, and nitrogen for superior resistance in harsh subsea and chemical environments.

Lean Duplex Grades: Lower nickel and molybdenum content for cost-sensitive applications with moderate corrosion risk.

These variants help engineers tailor material choice to budget, operating environment, and required performance metrics.