1J50 Soft Magnetic Alloy: Properties, Specifications, Applications & Kovar Difference | ZYTC Alloy
1J50 is an iron-nickel soft magnetic Alloy specified by the Chinese national standard GB/T 32286.1 (Soft Magnetic Alloys – Part 1: Iron-Nickel alloys), which replaces the former GB/T 32286 standard. The designation “1J50” signifies: “1” for soft magnetic, “J” for precision alloy, and “50” for the nominal nickel content of approximately 50%. 1J50 is renowned for its high magnetic permeability, high saturation magnetic induction, low coercive force, and low iron loss, making it an ideal choice for manufacturing high-precision electromagnetic components such as transformer cores, relay magnetic circuits, magnetic shields, and sensitive instruments.
At ZYTC Alloy, we specialize in the production and supply of 1J50 in a comprehensive range of forms, including 1J50 Plate, 1J50 Sheet, 1J50 Strip, 1J50 Wire, 1J50 Bar, 1J50 Rod, 1J50 Tube, 1J50 Pipe, and 1J50 Forgings. We also offer custom machining and 1J50 fabrication according to customer drawings. Our 1J50 products are manufactured strictly in accordance with GB/T 32286.1-2015, and we also comply with international standards including ASTM A753 Alloy2, AISI, ISO, JIS, and AMS to meet diverse global requirements. With a commitment to standardized, process-driven, and professional production and inspection procedures, every 1J50 shipment from ZYTC Alloy is thoroughly tested and qualified before delivery to our valued customers.
Chemical Composition of 1J50 (wt%)
The chemical composition of 1J50 is strictly controlled to ensure consistent magnetic and mechanical properties. The nickel content is maintained at approximately 50%, which minimizes the magnetocrystalline anisotropy constant and magnetostriction coefficient – the fundamental basis for achieving high initial and maximum permeability. Trace elements such as manganese and silicon are carefully added, while impurities like carbon, sulfur, and phosphorus are kept to extremely low levels to prevent the formation of non-magnetic inclusions that would pin domain wall motion and increase coercive force.
| Element | C | Si | Mn | P | S | Ni | Cu | Fe |
|---|---|---|---|---|---|---|---|---|
| 1J50 | ≤0.03 | 0.15–0.30 | 0.30–0.60 | ≤0.02 | ≤0.02 | 49.0–50.5 | ≤0.20 | Balance |
Source: GB/T 32286.1-2015 / ASTM A753 Alloy2
Mechanical Properties of 1J50
1J50 exhibits excellent mechanical properties that support a wide range of manufacturing processes. In the soft annealed state, 1J50 offers good ductility and formability, making it suitable for stamping, drawing, and winding operations. In the hard-rolled state, 1J50 demonstrates significantly higher strength for applications requiring greater structural integrity.
| Property | Soft State | Hard State |
|---|---|---|
| Tensile Strength Rm (MPa) | 450 | 785 |
| Yield Strength Rp0.2 (MPa) | 150 | 685 |
| Elongation A (%) | 37 | 3 |
| Brinell Hardness (HBW) | 130 | 170 |
Physical Properties of 1J50
| Property | Value |
|---|---|
| Density (g/cm³) | 8.2 |
| Electrical Resistivity (μΩ·m) | 0.45 |
| Curie Temperature (°C) | 500 |
| Saturation Magnetostriction Coefficient (×10⁻⁶) | 25 |
Magnetic Properties of 1J50
The magnetic performance of 1J50 is what truly sets it apart. 1J50 offers a balanced combination of high saturation magnetic induction and good permeability, making it the material of choice for medium-field electromagnetic applications. Unlike ultra-high permeability alloys such as 1J79 and 1J85 (which contain approximately 80% nickel), 1J50 excels in power conversion and energy transmission rather than weak signal detection. The magnetic properties of 1J50 are highly dependent on the final heat treatment process – annealing in a pure hydrogen atmosphere or vacuum at high temperatures is essential to achieve recrystallization, purification, stress relief, and optimal grain structure.
| Product Form | Thickness/Diameter (mm) | μ₀.₄ (mH/m) ≥ | μₘ (mH/m) ≥ | Hc (A/m) ≤ | Bs (T) ≥ |
|---|---|---|---|---|---|
| Cold-rolled strip | 0.10–0.19 | 8.0 | 85 | 9.2 | 1.5 |
| Cold-rolled strip | 0.20–0.35 | 9.0 | 90 | 6.5 | 1.5 |
| Hot-rolled (forged) flat | 3–22 | 6.0 | 50 | 8.0 | 1.5 |
| Hot-rolled (forged) bar | 8–100 | 6.0 | 50 | 8.0 | 1.5 |
Applications of 1J50
1J50 is widely used across multiple industries due to its excellent magnetic properties and good processability. Typical applications of 1J50 include:
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Transformer Cores: Small and medium-power transformers, pulse transformers, and output transformers operating at low to medium frequencies
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Relay Magnetic Circuits: High-sensitivity relays requiring precise actuation thresholds
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Magnetic Shields: Precision instrument magnetic shielding enclosures to eliminate electromagnetic interference
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Electromagnetic Clutches and Brakes: Iron cores for electromagnetic clutches and torque motors
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Instrumentation: Aerospace precision control instruments, gyroscope instruments, and magnetic sensors
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Motor Components: Rotor and stator components for specific types of motors
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Magnetron Pole Pieces: Components for focusing and directing magnetic fields
1J50 vs Kovar – What’s the Difference?
While both 1J50 and Kovar are iron-nickel-based precision alloys, they serve fundamentally different purposes and possess distinctly different properties.
Kovar (typically designated as 4J29 or UNS K94610) is an iron-nickel-cobalt alloy containing approximately 29% nickel and 17% cobalt. It is a controlled-expansion alloy designed to have a coefficient of thermal expansion closely matching that of hard glass and ceramics in the 20–450°C range. This makes Kovar the material of choice for glass-to-metal and ceramic-to-metal hermetic sealing applications, such as semiconductor packages, vacuum tubes, and electronic component enclosures.
1J50, by contrast, is a soft magnetic alloy with approximately 50% nickel and the balance iron. Its primary function is not thermal expansion matching but magnetic performance – high permeability, high saturation induction, and low coercive force. 1J50 is used in applications where magnetic flux needs to be efficiently conducted, switched, or shielded, such as transformer cores, relays, and magnetic shields.
| Feature | 1J50 | Kovar (4J29) |
|---|---|---|
| Primary Function | Soft magnetic (high permeability) | Controlled thermal expansion (glass sealing) |
| Ni Content | 49.0–50.5% | ~29% |
| Co Content | None | ~17% |
| Key Property | High Bs, low Hc | Matched CTE with glass/ceramic |
| Typical Use | Transformer cores, relays, magnetic shields | Semiconductor packages, vacuum tube seals |
In summary: choose 1J50 when you need magnetic performance; choose Kovar when you need thermal expansion matching for glass or ceramic sealing.
Why Choose ZYTC Alloy for 1J50?
At ZYTC Alloy, we are committed to delivering 1J50 products of the highest quality:
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Comprehensive Product Range: 1J50 Plate, 1J50 Sheet, 1J50 Strip, 1J50 Wire, 1J50 Bar, 1J50 Rod, 1J50 Tube, 1J50 Pipe, and 1J50 Forgings
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Custom Fabrication: We accept 1J50 drawings for custom machining and fabrication
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International Standards Compliance: GB/T 32286.1-2015, ASTM A753 Alloy2, AISI, ISO, JIS, AMS
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Strict Quality Control: Standardized, process-driven, and professional production and inspection
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Fast Delivery: Competitive lead times with reliable shipping
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Competitive Pricing: High-quality 1J50 at reasonable prices
Contact ZYTC Alloy today to discuss your 1J50 requirements. Whether you need 1J50 Plate, 1J50 Bar, 1J50 Strip, 1J50 Wire, 1J50 Tube, or custom 1J50 forgings – we have the expertise and capacity to deliver.
1J50 | GB/T 32286.1 | ASTM A753 | Soft Magnetic Alloy | Fe-Ni Alloy | Permalloy | High Permeability | Precision Alloy | Nickel-Iron Alloy | Magnetic Alloy | Transformer Core | Relay Core | Magnetic Shield | 1J50 Plate | 1J50 Bar | 1J50 Strip | 1J50 Wire | 1J50 Tube | 1J50 Forgings | K94840 | Alloy50 | Ni50 | Hy-Ra49
