Invar 36 Sheet

Product Description

Invar 36 is a remarkable alloy discovered by French physicist C.E. Guialme in 1896. This alloy exhibits a unique property where its thermal expansion coefficient significantly decreases near its magnetic transition temperature, known as the Curie point. This phenomenon, called "abnormal thermal expansion," allows Invar 36 to maintain minimal or even near-zero expansion over a wide temperature range near room temperature. With a face-centered cubic structure, Invar 36 is designated as 4J36 in China, where it is also known as Yingang. Its English name, Invar, derives from the word "invariable," reflecting its ability to maintain nearly constant dimensions.

Another related alloy, 4J32, is often referred to as Super-Invar. It boasts an even lower thermal expansion coefficient than 4J36 within the temperature range of -60°C to 80°C. However, its low-temperature microstructure stability is inferior to that of 4J36. Super-Invar is primarily used in the manufacture of highly precise instruments and components that require exceptional dimensional stability under ambient temperature variations.

Invar 36, or 4J36 alloy, is a specialized low-expansion iron-nickel alloy composed of approximately 36% nickel, 63.8% iron, and 0.2% carbon. It is renowned for its ultra-low thermal expansion coefficient, enabling it to maintain a fixed length across a broad temperature range. Additionally, its thermal elastic coefficient remains practically zero over a wide temperature range, meaning its Young's modulus remains unchanged. This combination of properties makes Invar 36 an invaluable material for applications requiring extreme precision and stability, such as in aerospace, scientific instruments, and high-precision engineering.

 

 

Chemical composition

Eraum	Content(%)	Ni	Fe	C	Mn	Si	S	P
4J36	min	35	balance	--	0.2	--	--	--
	max	37		0.05	0.6	0.3	0.02	0.02

 

Typical Room Temperature Mechanical Properties Mill Annealed

Temperature		Yield Strength		Tensile Strength		Elongation on 50 mm	Reduction of Area %
		0.2% Offset				(2 inch) %
℃	℉	(MPa)	psi	(MPa)	psi
20	68	240	35	490	71	42	70

 

Properties of Invar 36 Sheet

• Low Thermal Expansion

Maintains minimal dimensional changes over a wide temperature range, making it ideal for precision applications.

• High Strength and Durability

Offers excellent mechanical strength and resistance to wear and fatigue.

• Good Machinability and Weldability

Can be easily machined, welded, and fabricated into complex shapes.

• Corrosion Resistance

Resists oxidation and corrosion in various environments.

• Magnetic Properties

Exhibits magnetic properties, which can be advantageous in specific applications.

 

Advantages of Invar 36 Sheet

• Exceptional dimensional stability in varying temperatures.
• High strength and durability for precision applications.
• Easy to machine, weld, and fabricate.
• Resists corrosion and oxidation, ensuring long-term performance.

Welding

Invar 36 can be welded by the convetional methods. Caution must be taken so as not to overheat the molten metal. This will avoid spattering of the molten metal and pits in the welded area. When filler rod is required , Invarod has been used.

 

Corrosion properties

Invar 36 is corrosion resistant in dry atmospheres at room temperature. Under unfavourable conditions, i.e., in humid or moist atmospheres, corrosion can occur in the form of rust.

Machinability

Invar is tough and ductile and therefore somewhat difficult to machine. It should be machined in the annealed condition. The machining characteristics of Invar 36 are similar to austenitic stainless steels. Because of its high ductility, the chips formed during machining tend to be stringy and tough and may thus impose rapid wear on the cutting tool edges. In general, slow speeds and light feeds should be used to avoid excessive heat and minimize the possibility of the generated heat affecting the expansion characteristics. An adequate depth of cut is important, however, in order to cut below any previously formed work-hardened zone. High speed steel or sintered carbide tools should be used and cutting edges should be kept sharp.

Forging

The principal precaution to observe in forging is to heat quickly and avoid soaking in the furnace. Long soaking may result in a checked surface due to absorption of sulfur from the furnace atmosphere and/or oxide penetration. A forging temperature of 2000/2150øF (1100/1180øC) is preferred. Invar alloy 36 may also be swaged and cold upset.

 

Applications of Invar 36 Sheet

• Aerospace

Used in satellite components, laser systems, and optical instruments requiring dimensional stability.

• Electronics

Ideal for precision components in electronic devices, such as lead frames and semiconductor equipment.

• Scientific Instruments

Employed in telescopes, microscopes, and other precision measurement tools.

• Energy Sector

Used in LNG (liquefied natural gas) tanks and pipelines due to its thermal stability.

• Industrial Machinery

Suitable for molds, fixtures, and tooling requiring minimal thermal expansion.

Pls confirm below information when you inquiry us

1. Delivery status: forged, cast, annealed, solid solution, aging state, etc;

2. Appearance status: black skin state, polished state, acid washed state;

3. Dimensional specifications: nominal size, tolerance range, fixed length, non fixed length, standard size;

4. Quality standards: GB, HB, GJB, AMS, GB/T, ASTM, ASME, JIS, DIN, EN, and others;

5. Product classification: Bar,Tube ,Strip, Wire,Flange,Plate,Ring,Round Cake,Forging ,casting Welding or drawing. We can produce according to your requirements

6. Order quantity

7. Delivery time

 

Our Advantages

Reliable Quality System

OEM/ ODM Services

No MOQ Required, More Opportunities

Excellent Pre-sales Service & After-sales Service

Fast Shipping & Best Price

 

Test Equipment

FAQ

Q:What information should i confirm you when i send inquiry

A:Sometimes we need product specification like material standard or Grade, size, Qty, shipping port, Terms like FOB or CIF etc.

Q: How long of the delivery time?

A: Usually, the shipment can be delivery within 15-30days after the order confirmed.

Q: How about the payment items?

A: LC, T/T, PayPal, Western Union etc.

Q: Which country have you exported to?

A: Our main market is South America, Middle East, Africa and Europe. And have built long time relationship with Pakistan, US, Norway, Germany, Korea, Russia,Taiwan customers.And got continue orders from them every month.

Q: Can i visit your factory?

A: Sure! Welcome in any time.

Q: How about the MOQ?

A: Normally we dont have MOQ requirement, We always expect more opportunities with you. But for some special material or special size let's communicate the actual status.

Q: Can you support us in the applications?

A: It is our pleasure!

Q: Can you accept the inspection from a third party?

A: Yes. We have enough experience to cooperate with the inspection project.

 

Contact Us

Invar 36 Sheet is a critical material for industries requiring precision and stability in extreme temperature conditions. If you need further details or technical specifications, feel free to ask!

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