4j78 Imported Precision Alloy Non-Magnetic Constant Expansion Magnetic Sealing High Hardness of The Soft Magnetic Alloy

• Product Type: Rod
• Material: Other
• Carbon Content: Other
• PCD: Other
• ET: Other
• Delivery: 7-15 Days
• Model NO.: 4J78
• Price Item: T/T,30% Payment in Advance,70% T/T After The Co
• Quality Control: Mill Test Certificate Is Supplied with Shipment
• Export Country: USA,Southeast Asia,MID East,Africa,Eastern Asia,
• Transport Package: Waterproof Cloth Packaging and on Pallets, or AC
• Specification: 2.0*1250*C/1.5*1250*C/0.8*1250*C/1.0*1250*C
• Trademark: China
• Origin: China

Product Description

4J78 
4J78 alloy has low magnetic permeability and lower expansion coefficient compared with other non-magnetic ceramic seal alloys, so it is called non-magnetic fixed expansion ceramic seal alloy. Adding a small amount of copper to the alloy can improve its processing performance. The overall performance of the alloy's ceramic seal is superior to that of non-magnetic ceramic seal materials such as Monel, stainless steel, and oxygen-free copper. It is mainly used as non-magnetic ceramic sealing material in electric vacuum devices.

4J78 heat treatment system The expansion coefficient performance test sample specified in the standard is heated to 1000-1050°C in a protective atmosphere or vacuum, kept for 30-40 minutes, cooled to below 300°C at a speed of no more than 5°C/min, and released from the furnace.
4J78 Variety Specifications and Supply Status Varieties include rods, tubes, plates, wires and strips.

4J78 Melting and Casting Process Vacuum induction furnace is used for melting.

4J78 Application Overview and Special Requirements The alloy has been used in the factory and has stable performance. The alloy is used as a non-magnetic ceramic sealing material for gyroscopes and other electric vacuum devices. In use, the heat treatment process should be strictly controlled to ensure that the alloy has good processing properties.
 

Chemical composition

C	P	S	Mn	Si	Mo	Cu	Ni
					20.0
0.05	0.020	0.020	0.40	0.30	22.0	1.5	allowance

Under the condition that the average linear expansion coefficient reaches the standard, the content of molybdenum and copper is allowed to deviate from the range specified in the table.

The melting temperature range of 4J78 is 1400~1420ºC.
4J78 thermal conductivity

  4J78 linear expansion coefficient

Average linear expansion coefficient of 4J78 alloy
 

θ/ºC	20	300	600		θ/ºC	20~500	20~600
λ/(W/(m·ºC))	13.8	15.5	16.7			12.1~12.7	12.4~13.0

 

θ/ºC	20~100	20~200	20~300	20~400	20~500	20~600	20~700	20~800	20~900	20~1000	20~1050
/10-6ºC-1	11.3	11.6	11.8	12.1	12.4	12.5	13.2	13.7	14.2	14.7

4J78 density ρ=9.38g/cm3.

4J78 electrical properties

4J78 resistivity ρ=1.17μΩ·m.

4J78 Magnetic Properties The standard stipulates that μ16000≤1.251×10-3mH/m. The magnetic permeability of the alloy under different magnetic field strengths is shown in Table 2-4.

4J78 Chemical Properties The alloy has high corrosion resistance in atmospheric, seawater and tropical climate conditions.

H/(A/m)	4000	8000	12000	16000	32000	40000	80000
μ/(10-3mH/m)	1.251	1.251	1.251	1.251	1.251	1.251	1.250

4J78 mechanical properties

Performance specified in 4J78 technical standard

Mechanical properties of 4J78 at room temperature and various temperatures

The hardness of 4J78 alloy (soft state) at room temperature is HV=234~247.

4J78 Tensile properties Tensile properties of alloy (soft state) at room temperature

σb/MPa	σs/MPa	δ(L0=50mm)/%
869	353	35

4J78 Durability and Creep Properties

4J78 fatigue performance

4J78 elastic properties Elastic modulus E=222GPa.

Solucky steel Limited is a third-party supply chain service enterprise focusing on materials for automobiles, high-end household appliances, as well as material processing and storage. Its headquarters and warehouse base are set up in Shanghai BaoShan, and has branches all over the country, 20+ subsidiary companies,including Foshan, Guangdong, Chongqing, Wuxi, etcz.
Main Products

 

Product Application

Machines & Processing

Packing & Delivery & logistics

Why Choose Us

FAQ
1.Where is your factory?
Our head office and warehouse located in Shanghai--the biggest steel making center of China 

2.How long is your delivery time?                                                                                
Generally it is 5-10 days if the goods are in stock. or it is 15-30 days if the goods are not in stock, it is according to quantity.      
                                                                         
3.What about the MOQ?                                                                                
MOQ only 200KG,include coils and sheets     
                                                                           
4. How long is your lead time?                                                                                
In general, our delivery time is within 7-15 days, and may be longer if the quantity is extremely large or special circumstances occur.
                                                                                
5.How's your product quality?                                                                                
We only sell mid to high end steel materials,100% quality guarantee and cost-effective.                                                                                
6.What are your terms of payment?                                                                                
You can make the payment to our bank account,T/T, 30% deposit in advance, 70% balance against the copy of B/L.  
                                                                             
7.How many countries you already exported to?                                                                                
We have exported to America, Canada, Brazil, Chile, Colombia, Russia, Ukraine, Thailand, Myanmar, Vietnam, India, Kenya, Ghana,somalia and other African countries.Our export experience is rich, we familiar with different market demands, can help customers avoid a lot of trouble.     
                                                                           
8.What are the certifications for your products?                                                                                
We have ISO 9001, MTC, third parties' inspections are all available such SGS, BV ect.