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Havar® • UNS R30004

Havar® is a heat treatable Cobalt base alloy that provides very high strength. The alloy has excellent corrosion resistance and is non-magnetic. Applications have included pressure diaphragms, power springs, gap spacers in magnetic heads, and target foils in nuclear physics.

Forming cold rolled Havar requires large radius (90° Bend – 8 X thickness) prior to age hardening. The joining can be accomplished using both welding and soldering techniques.The ultimate endurance life is achieved by heat treating the alloy at 1000°F after 80% cold work. The alloy will retain 75% of room temperature strength up to 950°F (Figure 1).

Available Sizes:

Havar® is available from Hamilton Precision Metals as strip product in thicknesses from 0.0005” to 0.025” (0.0127 mm to 0.635 mm) and widths to 7.5” (190.5 mm). A foil product is available in thicknesses down to 0.000060” and widths of 4.0” (101.6 mm). The material corresponds to UNS R30004.

Nominal Composition
HAVAR® NOMINAL COMPOSITION
Cobalt 42.0%
Chromium 19.5%
Nickel 12.7%
Tungsten 2.7%
Molybdenum 2.2%
Manganese 1.6%
Carbon 0.2%
Iron Balance


Mechanical Properties
HAVAR® MECHANICAL PROPERTIES
ANNEALED COLD ROLLED COLD ROLLED
HEAT TREATED
Ultimate Tensile Strength 140,000 PSI 270,000 PSI 330,000 PSI
Yield Strength (0.2% Offset) 70,000 PSI 250,000 PSI 300,000 PSI
Elongation in 2” * 40% 1% 1%
Hardness RC 25 RC50 RC60
Modulus of Elasticity (Tension) 29.5 x 106 PSI - -

*The measured elongation will be less as thickness decreases to 0.002” and less.
These values may be adjusted by control of process variables – consult HPM for desired values.


Physical Properties
HAVAR® PHYSICAL PROPERTIES
Density 0.300 lbs/cu.in.
Melting Point (Approx.) 1480°C
Electrical Resistivity @ R.T. 92 Microhm·cm
Thermal Expansion Coefficient (0° to 50°C) 12.5 x 10-6/°C
Thermal Conductivity 13.0 W/m·K
Magnetic Attraction None

Typical values to guide alloy selection but are not a guarantee of minimum or maximum.