Soft Magnetic Alloy 1J50 · UNS K94490 · GB 1J50
Soft Magnetic Alloy 1J50 (K94490): composition, properties, fittings and flanges
Soft Magnetic Alloy 1J50 (K94490, GB 1J50) is Iron-nickel 50 % soft magnetic alloy. Soft Magnetic Alloy 1J50 is specified at Nickel 49.0 - 51.0, Copper 0.20 max. 1J50 is the general-purpose 50 % nickel soft magnetic alloy: high saturation flux and moderate permeability make it the standard choice for transformer cores, relays…
- UNS
- K94490
- W. Nr.
- -
- Density
- 8.20 g/cm³ (0.296 lb/in³)
- Key strength
- 450 MPa / 65 ksi
Identification and standards
| Short form | Soft Magnetic Alloy 1J50 · UNS K94490 · GB 1J50 |
|---|---|
| Classification | Iron-nickel 50 % soft magnetic alloy |
| UNS | K94490 |
| Werkstoff number | - |
| Material family | Precision Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Iron (Fe) | Balance | Matrix |
| Nickel (Ni) | 49.0 - 51.0 | Sets the magnetic properties |
| Manganese (Mn) | 0.30 - 0.60 | Resistivity and processing |
| Silicon (Si) | 0.15 - 0.30 | Resistivity |
| Carbon (C) | 0.03 max | Kept low - carbon degrades permeability |
| Phosphorus (P) | 0.020 max | - |
| Sulphur (S) | 0.020 max | - |
| Copper (Cu) | 0.20 max | - |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (annealed) | 450 MPa / 65 ksi |
|---|---|
| 0.2 % yield strength, min | 250 MPa / 36 ksi |
| Elongation in 2 in, min | 25 % |
| Typical hardness, annealed | 130 - 170 HB |
| Saturation flux density, typical | About 1.5 T |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 8.20 g/cm³ (0.296 lb/in³) |
|---|---|
| Melting range | 1430 °C (2610 °F) |
| Modulus of elasticity | 158 GPa (22.9 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 14.5 W/m·K |
| Curie temperature | About 500 °C |
| Electrical resistivity | About 45 µΩ·cm |
Specifications by product form
| Forgings & flanges | To order against GB/T 15018 (1J50) |
|---|---|
| Butt weld fittings | Not normally supplied |
| Seamless pipe & tube | Not normally supplied |
| Plate / sheet / strip | GB/T 15018 / ASTM A753 family |
| Bar / rod | GB/T 15018 |
| Welding consumables | Welding degrades magnetic properties - braze or bond instead |
| UNS / EN / China | UNS K94490 · GB 1J50 |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Forged flanges blanks and finished flanges to ASME B16.5, B16.47 Series A/B and B16.36
- Butt weld elbows, tees, reducers, caps and stub ends to ASME B16.9 and MSS SP-43
- Seamless pipe and tube to the applicable ASTM / ASME pipe specification
- Forged rings, discs and hubs machined to your drawing
Typical applications
- Transformer and inductor laminations
- Relay armatures, pole pieces and magnetic shields
- Instrument and sensor magnetic circuits
- Aerospace and defence electromagnetic components
Welding, forming and machining
- Welding
- Fusion welding is avoided because it destroys the magnetic properties in the heat affected zone. Parts are stamped or cut and then given the final magnetic anneal.
- Heat treatment
- Final magnetic anneal at 1050 - 1150 °C in dry hydrogen, then controlled cool to develop maximum permeability.
- Hot and cold forming
- Hot work in the range stated by the mill for this grade, then re-solution or re-age before final machining so that the delivered condition matches the certificate.
- Machining
- Machine with sharp carbide or high-speed steel tooling, positive rake, constant feed and ample coolant. Never dwell - the surface work-hardens quickly.
Buy Soft Magnetic Alloy 1J50 from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.