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Carburizing Resistant Cr20Ni35 Nickel Chromium Wire for Controlled Atmosphere Furnaces
High performance Cr20Ni35 nickel chromium heating and resistance wire designed for controlled atmosphere heat treatment furnaces, offering superior anti-carburizing longevity and stable electrical resistivity.
- Overview
- Features
- Technical Specifications and Chemical Composition
- Applications
- Advantage
- FAQ
- Recommended Products
Cr20Ni35 nickel chromium alloy wire is an austenitic resistance material specifically formulated for electric heating elements operating in carbon rich and protective atmosphere industrial furnaces. With a balanced matrix of 35% nickel, 20% chromium, and iron, it delivers outstanding resistance to carbon penetration, internal oxidation, and structural embrittlement at continuous operating temperatures up to 1100°C.
Product Overview
Cr20Ni35 Nickel Chromium Resistance Heating Wire Cr20Ni35 is an iron nickel chromium electrical resistance alloy developed to solve premature element failure in carburizing, carbonitriding, and reducing furnace atmospheres. In traditional high nickel or binary nickel chromium elements, exposure to hydrocarbon gases and fluctuating carbon potentials often leads to rapid carbon absorption, severe swelling, and localized green rot degradation.
By incorporating a dense, protective silicon and chromium oxide surface layer, Cr20Ni35 wire effectively blocks carbon ingress into the alloy core. This metallurgical stability prevents grain boundary carbide precipitation and maintains high ductility across extended thermal cycles. The alloy exhibits stable electrical resistivity across its entire temperature profile, high hot strength, and minimal sag when formed into coiled or wave shaped industrial heating elements.
Key Features
High Temperature Carburization Resistance and Thermal Durability Superior Carburization and Carbon Ingress Resistance. The alloy composition forms a tight barrier against active carbon atoms, preventing catastrophic carburization and embrittlement in endothermic, exothermic, and cracked ammonia gas atmospheres.
High Operating Temperature and Creep Resistance Maintains structural integrity and dimensional stability at continuous service temperatures up to 1100°C (2012°F), minimizing element deformation and sagging over long campaign runs.
Stable Electrical Resistivity Delivers predictable and consistent resistance characteristics (1.04 microhm meter at 20°C) with low resistance drift over years of thermal cycling.
Excellent Workability and Coiling Performance Fully annealed wire exhibits superior ductility and uniform tensile properties, allowing effortless winding into tight coils, zig zag elements, or heavy gauge rod frames without micro cracking.
High Resistance to Green Rot and Oxidation Resists selective internal oxidation under alternating oxidizing and reducing furnace atmospheres where standard heating alloys fail prematurely.
Chemical Composition
| Element | Content (%) |
|---|---|
| Nickel (Ni) | 34.0 - 37.0 |
| Chromium (Cr) | 18.5 - 21.0 |
| Silicon (Si) | 1.0 - 1.75 |
| Manganese (Mn) | 1.0 max |
| Carbon (C) | 0.08 max |
| Iron (Fe) | Balance |
Physical and Mechanical Properties
| Parameter | Value |
|---|---|
| Density | 7.90 g/cm3 |
| Electrical Resistivity at 20°C | 1.04 microhm·m |
| Maximum Continuous Operating Temperature | 1100°C |
| Melting Point | 1390°C |
| Tensile Strength (Annealed) | 650 - 750 MPa |
| Elongation (Annealed) | >= 20% |
| Temperature Coefficient of Resistance (20-1000°C) | 0.00032 /°C |
| Minimum Order Quantity (MOQ) | 10 kg |
Available Supply Forms and Dimensions
| Product Form | Diameter / Dimension Range | Surface Condition |
|---|---|---|
| Fine Wire | 0.05 mm - 0.80 mm | Bright Annealed, Spooled |
| Medium Wire | 0.80 mm - 3.00 mm | Bright / Matte Annealed, Spool or Coil |
| Heavy Gauge Wire / Rod | 3.00 mm - 10.00 mm | Clean Annealed, Coil or Straight Length |
| Flat Wire / Strip | Thickness 0.1 - 2.5 mm, Width 1.0 - 50 mm | Bright Annealed, Spooled / Coiled |
Industrial Applications
- Atmosphere Furnace Heating Elements Controlled Atmosphere Heat Treatment Furnaces: Ideal for sealed quench furnaces, pit carburizing furnaces, and mesh belt continuous hardening lines.
- Endothermic and Exothermic Gas Generators: Heating elements inside gas reforming retorts and atmosphere generation units.
- Brazing and Sintering Furnaces: Continuous belt heating zones operating under protective hydrogen or dissociated ammonia atmospheres.
- Industrial Kilns and Heating Chambers: Radiant heating tubes, open coil heaters, and ceramic bobbin heating units in chemical and metallurgical processing.
Why Choose DLX Alloy?
- Manufacturing Capacity and Engineering Support Integrated Manufacturing Scale: Operating advanced vacuum induction melting, electroslag remelting, precision hot rolling, and multi stage cold wire drawing facilities with a monthly production capacity of 1,200 tons.
- Full Batch Quality Traceability: Every spool and coil undergoes strict spectrometer chemical verification, continuous laser diameter measurement, and automated resistance testing before shipment.
- Flexible Customization and Low MOQ: Supporting custom wire diameters, flat wire cross sections, specific spooling standards (DIN125, DIN160, DIN200, DIN250), with a low MOQ of 10 kg for standard stock specifications.
- Global B2B Logistics: Secure moisture proof, export seaworthy packaging in cartons and wooden crates, with responsive technical engineering support for furnace element design and resistance calculations.
Frequently Asked Questions: Cr20Ni35 Alloy Selection and Application
- Why is Cr20Ni35 preferred over binary 80/20 Nickel Chromium in carburizing atmospheres?
Binary 80/20 Nickel Chromium alloy is highly susceptible to carbon absorption and green rot under reducing or carbon rich atmospheres at elevated temperatures. Cr20Ni35 contains an optimized balance of iron, nickel, chromium, and silicon that forms a stable protective oxide barrier, resisting carbon penetration and extending element service life in carburizing furnaces.
- What is the maximum recommended operating temperature for Cr20Ni35 wire?
The maximum recommended continuous operating temperature in air and controlled atmospheres is 1100°C (2012°F). In clean oxidizing conditions, short term peak exposure can reach up to 1150°C.
- How is Cr20Ni35 wire packaged for international shipment?
Fine and medium wires are precision wound on standard plastic spools (such as DIN160, DIN200, DIN250) and vacuum sealed in plastic foil to prevent oxidation during transit. Heavy gauge wire is packed in securely strapped coils with protective wrapping inside export grade wooden crates.
- Can DLX provide customized wire dimensions and pre-oxidized surface treatments?
Yes. DLX manufactures custom wire diameters ranging from 0.05 mm to 10.00 mm with tight dimensional tolerances. Custom surface finishes, including bright annealed, oxidized, and pre-formed heating coils, can be supplied according to customer engineering drawings.
