204Cu stainless steel spring wire

Alloy 204Cu is a chromium-manganese austenitic stainless steel that contains 2-4% copper and 0.05-0.25% nitrogen, designed specifically to enhance both strength and ductility. The added copper content in 204Cu stainless steel spring wire enhances corrosion resistance and machinability, making it an ideal choice over other austenitic stainless steels in certain applications. Although 204Cu becomes slightly magnetic when cold-worked, this effect can be minimized with specialized processing techniques. Positioned between the 200 and 300 series in terms of cost and performance, 204Cu stainless steel spring wire is a versatile solution for various applications.

Applications of 204Cu Stainless Steel Spring Wire

• Screening equipment for coal slurry in the coal handling industry
• Hinge pins for high-strength and corrosion-resistant parts
• Baskets used in the tobacco industry
• Components where enhanced non-magnetic properties and galling resistance are required, surpassing 304 and 304HQ

Typical Chemistry of 204Cu Stainless Steel Spring Wire

• Carbon: 0.15% max
• Phosphorus: 0.060% max
• Silicon: 1.00% max
• Nickel: 1.50-3.50%
• Chromium: 15.50-17.50%
• Manganese: 6.5-9.0%
• Copper: 2.00-4.00%
• Molybdenum: 1.00% max
• Sulfur: 0.030% max
• Nitrogen: 0.05-0.25%
• Iron: Balance

Physical Properties of 204Cu Stainless Steel Spring Wire

• Density: 0.282 lb/in³, 7.81 g/cm³
• Electrical Resistivity: 30.039 ohm-in
• Specific Heat: 0.119 BTU/lb-°F (0.511 J/g-°C) at 73-212°F
• Thermal Conductivity: Increases from 93.79 BTU-in/hr-ft²-°F at 122°F to 154.43 BTU-in/hr-ft²-°F at 932°F
• Coefficient of Thermal Expansion: Ranges from 9.50 µin/in-°F at 77-212°F to 10.83 µin/in-°F at 77-1202°F
• Modulus of Elasticity: 29 x 10³ KSI in tension
• Magnetic Permeability: 1.02 max in the annealed state
• Melting Range: 2552-2642°F (1400-1450°C)

Mechanical Properties of 204Cu Stainless Steel Spring Wire (Room Temperature)

• Annealed State
  • Ultimate Tensile Strength: 92 KSI (635 MPa)
  • Yield Strength: 42 KSI (290 MPa)
  • Elongation: 75%

Cold-Worked 204Cu Stainless Steel Spring Wire
Cold working increases strength and reduces elongation in 204Cu stainless steel spring wire:

• 10% Cold Worked

  • Ultimate Tensile Strength: 108 KSI
  • Yield Strength: 81 KSI
  • Elongation: 49%

• 30% Cold Worked

  • Ultimate Tensile Strength: 149 KSI
  • Yield Strength: 133 KSI

For higher strength or custom tempers, Alloy 204Cu stainless steel spring wire can be cold-worked further, with support from specialized technical services for custom requirements.