ASTM A753 Type 4 – Alloy 79

Consisting of 80% Nickel, 5% Molybdenum, and the balance Iron, this alloy is used where maximum permeability and extremely high initial permeability is required, along with minimum hysteresis.

Also known as: Magnifer 79042, Carpenter HyMu 801, Hipernom1, Moly-Permalloy, Permalloy 80, Mumetal3

Applications

  • Electro-magnetic shielding
  • Speciale transformer laminations
  • Toroidal tape wound cores
  • High quality motor laminations
  • Stepping motors


Type 2 – Alloy 50

Consisting of 49% Nickel and 51% Iron, this alloy is used where high initial permeability, maximum permeability, and low core loss is needed.

Also known as: Magnifer 502, Carpenter High Permeability 491, Alloy 4750, Supra 503

Applications

  • Transformer cores
  • Highly efficient motors
  • Shielding and specialised electronic devices, such as LF power transducers, chokes, relay parts, solenoids and oscillators.


ASTM A753 Type 1 – Radiometal 4550

Consisting of 45% Nickel and the balance Iron, this alloy has excellent permeability with high saturation flux density.

Applications

  • Sensitive relays that need to respond to very weak currents
  • Transformers
  • chokes and special motors where the properties of silicon-iron do not provide the required magnetic performance


ASTM A801 – Hiperco 501

Consisting of 49% Cobalt, 49% Iron, and 2% Vanadium Hiperco 50 has the highest magnetic saturation of any commercial alloy, and greater mechanical strength than other soft magnetic alloys.

Also known as: AFK 502, VACOFLUX 50, Permendur 49, Rotelloy 3

Applications

  • Electrical generators
  • Pole pieces for electromagnets
  • Magnetic bearings
  • High magnetic flux devices and instruments


ASTM A848 Type 1 – Vim Var Core Iron

Carpenter VIM VAR Core Iron is a low carbon magnetic iron produced using vacuum induction melting and vacuum arc re-melting processes.

Other elements commonly found in low carbon irons are held as low as possible to ensure good DC magnetic properties. The double melting technique keeps the distribution of non-metallic inclusions to a minimum length and frequency so that thin wall sections will not contain leaks due to internal discontinuities.

Also known as: Carpenter Consumet Core Iron1

Applications

  • Used in components where vacuum integrity is needed, such as power tubes and microwave devices
  • Relays, solenoids, magnetic pole pieces for scientific instruments


ASTM A848 Type 1 – Soft Magnetic Iron

This product has an Iron content of 99.85% Min, without the addition of alloy elements. All natural impurities have been largely removed.

Pure iron undergoes pacification after melting by means of vacuum degassing following solidification. It therefore has a homogenous composition with regard to distribution of the accompanying elements, a very low oxygen content, and due to the low Carbon content, the micro structure consists of pure ferrite.

This material supports excellent magnetic properties and resistance against corrosion and oxidation. It has good cold forming capabilities and is well suited to welding.

Also known as: Remko, Armco, Maximag

Applications

    • Aviation construction
    • Nuclear technology
    • Magnet production
    • Automotive construction
    • Power station construction
    • Gaskets in the chemical and petrochemical industries
    • Magnetic shielding
    • Welding rods and fuse wire
    • An anti-corrosion anode


Soft Magnetic Alloy Property Comparisons

Physical Properties UNIT ASTM A753 Type 4 ASTM AT53 Type 2 Hiperco 50 ASTM A848 Type 1 - Vim Var Core Iron
Density lb/cu in 0.316 0.295 0.293 0.284
Specific Gravity 8.74 8.18 8.12 8.86
Curie Temp °F 860 840 715 1400
Curie Temp °C 460 450 380 760
Melting Point °F 2650 2600 2600
Melting Point °C 1454 1427 1427
Electrical Resistivity micro-ohm-cm 59 49 41 13
Electrical Resistivity ohm-cir mil/ft 349 290 240 78
Thermal Conductivity W/cm °C 0.35 0.13 0.29 0.73
Thermal Conductivity BTU-in/sq. ft-hr-°F 240 90 200 508
Specific Heat Cal/g-°C 0.12 0.11
Specific Heat BTU/lbm-°F 0.12 0.11
Thermal Expansion ppm/°F (75°F to 842°F) 7.5 5.0 5.6 8.2
Thermal Expansion ppm/°C (25°C to 450°C) 13.6 9.0 10.2 14.7

Mechanical Properties UNIT ASTM A753 Type 4 ASTM AT53 Type 2 Hiperco 50 ASTM A848 Type 1 - Vim Var Core Iron
Tensile Strength ksi 98 75 118 50
Tensile Strength MPa 676 518 814 345
Yield Strength ksi 38 23 63 27
Yield Strength MPa 262 159 435 190
Elongation % in 2 in. 40 40 9 45
Typical Hardness Rockwell HRB 85 HRB 80 HRC 20 HRB 60
Modulus of Elasticity Mpsi 31.4 24 30 30
Modulus of Elasticity kMPa 217 166 207 207

Chemistry UNIT ASTM A753 Type 4 ASTM AT53 Type 2 Hiperco 50 ASTM A848 Type 1 - Vim Var Core Iron
Maximum % unless noted Iron Bal 49 49 nom. 99.8 nom.
Maximum % unless noted Nominal Nickel 80 51 - 0.08
Maximum % unless noted Nominal Cobalt - - 49 nom. -
Maximum % unless noted Molybdenum 5.0 nom. - - -
Maximum % unless noted Carbon 0.03 0.02 0.01 0.02
Maximum % unless noted Manganese 0.95 0.5 - 0.12
Maximum % unless noted Silicon 0.42 0.35 0.05 0.12
Maximum % unless noted Vanadium - - 2 nom. 0.05
Maximum % unless noted Niobium - - 0.05 -
Maximum % unless noted Phosphorus 0.02 - - 0.01
Maximum % unless noted Sulfur 0.008 - - 0.01

Specifications ASTM A753 Type 4 ASTM AT53 Type 2 Hiperco 50 ASTM A848 Type 1 - Vim Var Core Iron
ASTM A753 A753 A801 A848
MIL N-1441C N-1441C A47182 -
AMS N-1441C N-1441C A47182 -

References

1Trademark Carpenter Technology Corp., Reading PA
2Trademark ThyseenKrupp-VDM, Germany
3Aperam Alloys