HyMu 80 (UNS N14080) Permalloy Alloy Tube
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HyMu 80 Permalloy Alloy Tube (1J85, ASTM A753 Alloy 8) | ZYTC Alloy
ZYTC Alloy, a specialized Chinese manufacturer and supplier of precision soft‑magnetic alloy tubular products, provides high‑quality HyMu 80 Permalloy seamless tubes. Also equivalent to Chinese grade 1J85 and ASTM A753 Alloy 8, this nickel‑molybdenum‑iron permalloy delivers ultra‑high initial permeability and low coercivity for precision electromagnetic components. Strict control over chemical composition, dimensional precision and final hydrogen annealing are mandatory to achieve qualified magnetic performance for magnetic shielding sleeves, precision transformer assemblies and weak‑signal transmission hardware.
1. Alloy Characteristics
HyMu 80 is a classic nickel‑iron‑molybdenum soft magnetic alloy designed for weak‑magnetic‑field service. Its prominent material features include extremely high initial permeability, very low coercive force and low high‑frequency power loss. The molybdenum addition plays a critical role in optimizing magnetic properties. In practical engineering applications, HyMu 80 tubes are widely adopted for precision transformer parts, magnetic shielding bushings and various electromagnetic components for weak‑signal transmission.
Surface quality is extremely critical for HyMu 80 tubular products. Oil contamination, rust, surface cracks, folds, deep scratches and oxide scale on inner or outer surfaces will degrade magnetic performance and interfere with subsequent machining and assembly. Strict surface inspection is implemented for every finished tube before delivery.
2. Applicable Industry & Procurement Specifications
Manufacturing HyMu 80 tubes presents greater challenges compared with permalloy bar and strip. Tight tolerances for outer diameter, inner diameter, wall thickness and length place high requirements on production equipment and process control.
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ASTM A753: Global core standard for nickel‑iron soft magnetic alloys; HyMu 80 corresponds to Alloy 8 type.
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GB/T 15018: Chinese domestic standard for equivalent grade 1J85 with matching chemical and magnetic requirements.
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Customer Drawings & Technical Agreements: Custom dimensions, tolerances and magnetic acceptance criteria often supersede general industry standards for these precision tubes.
Tube Dimension Scope
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Outer Diameter ¡Á Wall Thickness: OD 6‑100 mm, WT 0.5‑10 mm. Cold‑drawn seamless tube is preferred for precision electromagnetic hardware due to superior dimensional accuracy and smooth inner‑wall surface; welded tube is available for non‑critical structures upon request.
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Standard Length: 2‑6 m, custom cut‑to‑length available. Length tolerances shall be specified for magnetic‑shielding sleeve applications.
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Straightness: Strict straightness requirements apply for slender tubing; permissible bending per meter shall be clearly defined on purchase documents.
Delivery Condition Selection Guidance: ZYTC Alloy offers HyMu 80 tubes in two supply states: cold‑drawn or fully annealed. Select annealed tubes if components will be assembled directly for magnetic service. Cold‑drawn tubes are suitable for customers who will perform forming and carry out final annealing in‑house after machining.
3. Chemical Composition (Weight %)
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Element
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Content Range
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|---|---|
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Nickel (Ni)
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79.0‑81.0
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Molybdenum (Mo)
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3.8‑5.2
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Iron (Fe)
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14‑16 (Balance)
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Manganese (Mn)
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¡Ü1.1
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Carbon (C), Sulfur (S), Phosphorus (P)
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Strict trace‑level control
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Vacuum melting is applied to minimize trace impurities. Low carbon, sulfur and phosphorus content is essential to guarantee stable magnetic behaviour of finished HyMu 80 tubes.
4. Mechanical Properties (Typical, Fully Annealed State)
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Property
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Typical Reference Value
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|---|---|
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Ultimate Tensile Strength
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¡Ý 690 MPa (100 000 psi)
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0.2% Offset Yield Strength
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¡Ý 300 MPa (44 000 psi)
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Elongation
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¡Ý 40 %
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Hardness
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¡Ü 80 HRB
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5. Core Magnetic Performance (Fully Hydrogen‑Annealed)
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Magnetic Parameter
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Typical Achievable Value
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|---|---|
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Initial Permeability (¦Ìi)
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20 000‑50 000 (Minimum acceptance ¡Ý20 000)
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Maximum Permeability (¦Ìm)
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100 000‑200 000
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Coercivity (Hc)
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< 2 A/m
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Saturation Magnetic Induction (Bs)
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0.75‑0.8 T
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Electrical Resistivity
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55‑62 ¦Ì¦¸¡¤cm
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Magnetic performance, rather than mechanical values, governs product acceptance. Every delivery batch is tested following ASTM A596 / ASTM A773 standards, and a complete magnetic‑test report is supplied alongside mill documentation.
6. Critical Heat‑Treatment Guidelines
Heat‑treatment determines final magnetic quality of HyMu 80. This high‑nickel permalloy readily absorbs carbon, sulfur and oxygen from furnace atmospheres, which will severely degrade magnetic properties if not properly protected.
Intermediate Annealing (Process Softening)
Conducted under dissociated ammonia, hydrogen, vacuum or inert protective atmosphere. Process temperature range: 788‑1010 ¡ãC; holding time shall not exceed one hour.
Final Annealing (For Optimum Magnetic Properties)
Final high‑temperature annealing must use dry pure hydrogen atmosphere with dew point below ‑40 ¡ãC. Vacuum annealing yields comparatively inferior magnetic performance and is not recommended for critical magnetic‑shielding service. Target temperature: 1121‑1177 ¡ãC, hold for 2‑4 hours. Controlled cooling procedure: cool furnace to 593 ¡ãC, then apply controlled cooling rate of 194‑334 ¡ãC/hour from 593 ¡ãC down to 371 ¡ãC. All oil, paint and surface contaminants must be completely removed prior to annealing. Parts shall be separated using magnesium‑oxide or aluminum‑oxide powder during heat‑treatment to avoid sticking.
7. Quality‑Inspection Process
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Dimensional Inspection: Multi‑point sampling measurement with micrometers to verify OD, ID and wall‑thickness tolerances complying with ASTM B751 or customer drawing requirements. Straightness is inspected using platform and feeler‑gauge method for slender tube lots.
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Magnetic‑Performance Testing: DC magnetic‑property testing per ASTM A596 / A773 before shipment. Report includes initial permeability, maximum permeability, coercivity and saturation induction.
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Chemical‑Composition Verification: Spectrometer inspection confirms nickel, molybdenum and trace‑element levels against specification limits.
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Surface & Supplementary Tests: Visual surface inspection, mechanical property verification and non‑destructive testing are performed as agreed with customers.
8. Typical Applications
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Magnetic‑shielding sleeves and tubular shielding housings for precision instruments and sensors
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Precision transformer and inductor tubular components
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Electromagnetic assemblies for weak‑signal transmission systems
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Special‑purpose electronic and laboratory measurement equipment
9. ZYTC Alloy Manufacturing Advantages
As an experienced Chinese supplier of precision soft‑magnetic alloy tubing, ZYTC Alloy controls full‑process production for HyMu 80 seamless tubes from vacuum melting, cold drawing to precision hydrogen annealing. Our strict process control ensures tight dimensional tolerances, clean inner‑outer surface finish and consistent magnetic performance. Each shipment is accompanied by mill test reports and magnetic‑performance test certificates. Our metallurgical engineering team provides technical consultation covering heat‑treatment advice, delivery‑condition selection and drawing review for global customers.
Contact Us
Contact ZYTC Alloy for datasheets, test sample availability, stock check and custom quotations for HyMu 80 Permalloy alloy tubes.
📧 Email: dominic@zytc-steel.com
📲 WhatsApp: +86 13132148618
📲 WhatsApp: +86 13132148618