9 CR soft magnetic alloy is a cost-optimized cobalt-iron-chromium
alloy with a higher saturation magnetic induction and significantly
improved corrosion resistance compared to other cobalt-iron alloys.
Due to the high resistivity and high magnetic saturation, 9 CR
alloy has better switching times and higher actuation than
conventional chrome steels.
With these unique properties, 9 CR alloy is suitable for components
and actuators with special requirements for corrosion resistance,
such as gasoline or biofuel injectors in the automotive industry or
solenoid valves for corrosive media operating with short switching
times and high pressures.
Chemical composition
| Element | C | Si | Mn | S | P | Cr | Co | Mo | Al | Fe |
| Wt(%) | ≤0.04 | ≤0.50 | ≤1.00 | ≤0.015 | ≤0.015 | 9.00-11.00 | 9.0-10.50 | 1.70-2.30 | 0.70-1.30 | Re |
MAIN PROPERTIES
Saturation polarization of JS = 1.80 T
High electrical resistivity of ρe= 0.79 µΩm
Excellent corrosion resistance in comparison to other CoFe alloys.
Cost-optimized CoFe alloy with low cobalt content of 9 wt%
TYPICAL APPLICATIONS
Actuator and solenoid valve applications in corrosive media
Physical properties
Density ρ:7.75g/cm3
Thermal conductivity (25 °C) λ:20W(m.K)
Thermal expansion coefficient (20-100°C)α:10.9x10-6/K
Electrical resistivity ρe:0.79 μΩm
STATIC MAGNETIC PROPERTIES
Coercivity HC:130 A/m
Saturation polarization Js: 1.80 T
Saturation magnetization BS at H = 40 kA/m:1.85T
Maximum permeability µmax:3,000
Magnetostriction constant λS:+30PPM
Curie temperature TC:800°C
Typical magnetic properties
| Magnetic Properties | B400(T) | B800(T) | B4000(T) | B8000(T) | B16000(T) | μm(mH/m) | HC(A/m) |
| 9 CR | 0.55 | 1.10 | 1.43 | 1.60 | 1.97 | 3.05 | 180 |
Mechanical properties (final annealed)
Young's modulus E: 180 GPa
Yield strength Rp0.2: 330 MPa
Tensile strength Rm: 490 MPa
Elongation A: 35%
Hardness: HV 170
Mechanical properties (hot rolled)
Yield strength Rp0.2: 410MPa
Tensile strength Rm: 600MPa
Elongation A: 30%
Hardness: HV 240
Forms of supply
• Solid rods, diameters 12.5 – 100 mm
• Wire material, diameters 0.2-12 mm
