Cast Arnokrome III0 pages
Cast Arnokrome™
nnnnProduct Information
nnnnArnokrome™ III, developed by The Arnold
nnnnEngineering Company, is a ductile permanent
nnnnmagnet alloy based on the iron-chromium-cobalt
nnnnalloy system. Since the cobalt content is lower
nnnnthan in alternative magnetic alloys, Arnokrome
nnnnmay offer a significant advantage in replacement
nnnnsituations in terms of price stability.
nnnnThe alloy has both good castability and ductility
nnnnwhich permits the manufacture of a wide variety
nnnnof product sizes and shapes. Arnokrome III may
nnnnbe sand cast into a variety of shapes, then
nnnnmachined and formed prior to magnetic heat
nnnntreating. By adjusting the heat treatment, the
nnnnalloy's magnetic properties can be tailored to
nnnnspecific permanent magnet requirements.
nnnnArnokrome III is isotropic. By controlled heat
nnnntreatment, coercive force is varied to specific
nnnnlevels between 50 and 300 oersteds to optimize
nnnnthe performance of the material for the
nnnncustomer's application. Arnold Engineering's
nnnnapplications personnel are available to provide
nnnntechnical assistance in the user's evaluation of
nnnnArnokrome. Arnokrome III can be supplied in
nnnnmost shapes available in Alnico products.
nnnnWhen choosing Arnokrome, the following factors
nnnnshould be considered:
nnnn• Magnetic characteristics: Arnokrome III is
nnnnbest suited for low coercivity applications.
nnnnBr = 11,000 gauss He = 50 - 300 oersteds
nnnn• Workability: Arnokrome III is machinable by
nnnnnormal methods prior to magnetic heat
nnnntreatment. After heat treatment, only
nnnngrinding is recommended.
nnnn• Cost: Due to the nature of the heat treat
nnnncycle required to develop magnetic
nnnncharacteristics, the lower coercivities are
nnnnless expensive. Higher coercivity requires a
nnnnlonger heat treat cycle.
nnnnArnokrome™ III is an excellent substitute for
nnnnVicalloy, Cunife, and cobalt steels in many
nnnnapplications.
nnnnContact your Arnold Sales
nnnnRepresentative or call Arnold directly
nnnnat 815-568-2000 for more
nnnninformation.
nnnnFor information on Arnold's complete
nnnnline of products, visit our website at
nnnnwww. grouparnold. com
nnnnCast Arnokrome III is machinable with standard
nnnnmetal-working tools.
nnnnChemistry
nnnnChemical Element
nnnnChromium
nnnnCobalt
nnnnIron
nnnnPhysical Properties
nnnnDensity
nnnnDiameters Available
nnnnElectrical Resistivity
nnnn(25°C)
nnnnThermal Conductivity
nnnn(100°C)
nnnnThermal Expansion
nnnn(30° to 100°)
nnnnTemperature Range
nnnnCoefficient
nnnn30° to 400°C
nnnn30° to 300°C
nnnn30° to 200°C
nnnn30° to 100°C
nnnnArnokrome I
nnnn26 - 30%
nnnn7 -10%
nnnnBalance
nnnn.277 lbs/cu in
nnnn(7.6 g/cc)
nnnn1.250" to 0.010"
nnnn69 X 10 s ohm-cm
nnnn0.05 cal/sq cm/cm/sec/°C
nnnn8.67 X 10"4 cm-cm"1-°C"1
nnnnMean Expansion
nnnn(cm-cm"1-°C"1)
nnnn10.4 X 10"6
nnnn10.2 X 10 s
nnnn9.84 X 10 s
nnnn8.67 X 10 s
nnnnMechanical Properties
nnnnSolution Heat Heat Treated
nnnn(Treated condition) (For desired He)
nnnnTensile Strength 75.000 psi 120,000 psi
nnnnYield Strength 50,000 psi 115.000 psi
nnnn% Elongation 25 6
nnnnHardness Rb 75 Rc 25
nnnnMagnetic Properties
nnnnMagnetic Remanence (gauss)
nnnnCoercivity (Oersteds)
nnnnEnergy Product (MGOe)
nnnnReversible Temperature
nnnnCoefficient of Magnetization
nnnnCurie Temperature
nnnnOrientation
nnnn9,000- 12,000 Br
nnnn50 - 300 He
nnnn0.4-1.2
nnnn-0.02% l°C
nnnn625°C
nnnnIsotropic
nnnnJune, 2004
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