Invar 36 Rod Manufacturer in China – Precision Low-Expansion Alloy Solutions

The Invar 36 Rod, also known as Iron Nickel Alloy Bar, is a low-expansion nickel-iron alloy with a unique coefficient of thermal expansion (CTE) close to zero. Comprising 36% nickel, this alloy is ideal for applications requiring dimensional stability across a wide temperature range. As a leading Invar 36 Rod manufacturer in China, we supply high-quality rods for industries demanding precision and reliability.

Price: Contact Us for a Custom Quote

For the most competitive pricing, reach out to our sales team directly. We offer customized quotes for Invar 36 rod price based on your specific requirements, including dimensions, quantity, and delivery timelines. Contact us today to discuss your needs!

Specifications of Invar 36 Bar

Our Invar Rod is available in various dimensions and finishes to meet diverse industrial requirements. Below are the typical specifications:

Diameter Range: 3 mm to 300 mm
Length: Up to 6 meters (custom lengths available)
Surface Finish: Cold drawn, hot rolled, polished, or as per request
Standards: ASTM F1684, MIL-I-23011
Shape Variants: Invar 36 round bar, square bar, hexagonal bar
Tolerances: As per ASTM standards or customer specifications

Key Features (Advantages)

Low Thermal Expansion: Maintains dimensional stability with a CTE of ~1.2 ppm/°C between -50°C and 100°C.
High Precision: Ideal for applications requiring minimal thermal distortion.
Good Strength: Offers sufficient mechanical strength for structural applications.
Machinability: Can be machined into precise shapes like Invar 36 round bar with proper techniques.
Corrosion Resistance: Moderate resistance to atmospheric corrosion and mild environments.

Applications

Invar 36 Bar is widely used in industries where precision and stability are critical. Common applications include:

Aerospace: Components like thermostat rods and precision instrument parts.
Electronics: Lead frames, shadow masks, and semiconductor packaging.
Scientific Instruments: Telescope components, laser systems, and cryogenic equipment.
Tooling: Precision molds and dies requiring minimal thermal expansion.
Telecommunications: Microwave waveguides and optical fiber systems.

Chemical Composition

The composition of Invar 36 ensures its low-expansion properties. Below is the typical chemical breakdown:

Element	Percentage (%)
Nickel (Ni)	35.0–37.0
Iron (Fe)	Balance
Manganese (Mn)	0.2–0.6
Silicon (Si)	0.4 max
Carbon (C)	0.05 max
Sulfur (S)	0.015 max
Phosphorus (P)	0.015 max

Mechanical Properties

Property	Value
Tensile Strength	490 MPa
Yield Strength (0.2% offset)	280 MPa
Elongation	30%
Hardness (Brinell)	140 HB
Density	8.05 g/cm³

Chemical Properties

Invar 36 exhibits moderate resistance to various corrosive environments:

Acids and Alkalis: Limited resistance to strong acids like hydrochloric or sulfuric acid; performs better in dilute solutions.
Atmospheric Conditions: Good resistance to rust in dry or mildly humid environments; may require protective coatings in harsh conditions.
Environmental Limits: Not recommended for prolonged exposure to highly corrosive media or temperatures above 400°C, as it may affect expansion properties.

Things to Note (Limitations)

High Temperatures: Above 400°C, low-expansion properties diminish; thermal expansion increases.
Corrosive Environments: Limited resistance to strong acids or saltwater; protective coatings recommended.
Machining Challenges: Work-hardens during machining; requires slow speeds and sharp tools.

Corrosion Data

Environment	Corrosion Rate (mm/year)	Conditions	Notes
Dry Atmosphere	<0.002	25°C, 12 months exposure	No significant corrosion
Humid Atmosphere (Coastal)	0.01	25°C, 12 months exposure	Slight surface rust; coating advised
Distilled Water	0.005	25°C, 6 months exposure	Minimal corrosion
5% Sulfuric Acid	0.15	30°C, 1 month exposure	Not recommended for prolonged exposure
5% Sodium Chloride (Saltwater)	0.08	25°C, 3 months exposure	Use protective coatings for marine use
5% Sodium Hydroxide (Alkaline)	0.015	40°C, 3 months exposure	Good resistance

Welding and Manufacturing Tips

Welding: Use TIG or MIG welding with matching Invar 36 filler metals. Avoid overheating to preserve low-expansion properties; preheating is not typically required.
Forming: Can be cold worked, but care must be taken due to work-hardening tendencies. Annealing may be needed for complex shapes.
Machining: Use sharp carbide tools at low speeds with heavy feeds. Lubrication is recommended to minimize heat buildup.
Fabrication: Ideal for applications requiring precision forging or rolling, such as Invar rod or Invar bar production.

Customer Reviews

Frequently Asked Questions

Q: What’s the main difference between Invar 36 Rods and standard stainless steel rods?

A: Invar 36 Rods has a significantly lower coefficient of thermal expansion compared to stainless steel, making it ideal for precision applications where dimensional stability is critical. Stainless steel, however, offers better corrosion resistance in harsh environments.

Q: Can Invar 36 Round Bar be used in high-temperature environments?

A: Invar 36 Round Bar maintains its low-expansion properties up to 400°C. Beyond this temperature, its CTE increases, so it’s not recommended for high-temperature applications without consulting our technical team.

Q: What industries typically use Invar 36 Bar?

A: Invar 36 Bar is commonly used in aerospace, electronics, scientific instrumentation, and telecommunications for applications requiring minimal thermal expansion and high precision.

Q: Is Invar 36 suitable for cryogenic applications?

A: Yes, Invar 36 retains its low-expansion properties and mechanical strength at cryogenic temperatures, making it ideal for applications like liquid nitrogen storage systems.

Q: What surface finishes are available for Invar 36 round bar?

A: We offer Invar 36 round bar in cold drawn, hot rolled, polished, or custom finishes. Contact us to discuss the best finish for your application.