Example of Silicon Carbide Advantage :
Schunk-Inex Silicon/Silicon Carbide Composite Radiant/Protective
Tubes
Mainly used in heat treating industry
Advantages of Using Si/SiC Radiant / Protective Tubes (INEX)
-
INEX tubes are reliable and have long life, even at high temperatures (2400°F).
-
Superior resistance to most corrosive atmospheres.
-
Provides good fracture toughness and resistance to thermal shock, oxidation,
and creep without extreme brittleness
Example 1: Much better creep, oxidation and carburization
resistance than metallic tubes (Mainly due to the
existence of SiC)
| Creep Test at 1350oC (2462oF)
The INEX Si/SiC composite tube on the left was tested
for 360 hours. The Alloy 600 tube on the right was tested less than one
hour. |
 |
Example 2: Better thermal shock resistance than mullite tubes
 |
Severe Thermal
Shock Test for INEX tubes
-
Test system: INBZ-1001
-
Input: 150,000 BTU/hr
-
Total Cycle: 5
-
Average Heat Rate: 160oF/min
-
Average Cool Rate: 256oF/min
Mullite tubes failed in the first cycle of this test. |
Composition of Schunk-Inex Composite Tubes
INEX tubes consist of silicon carbide (SiC) in a silicon
(Si) matrix, and are made by a patented, simple fabrication process using
low-cost abundant raw materials.
Key Physical Characteristics
-
Thermal Expansion: 4.2 x 10-6 in/in/°F
-
Strength vs. Temperature:
|
|
Room Temp
|
8,520 PSI
|
|
1000°C (1832°F)
|
8,620 PSI
|
|
1250°C (2282°F)
|
10,097 PSI
|
|
1350°C (2462°F)
|
10,491 PSI
|
Long-Term Field Use
Both commercial and captive heat treat facilities around
the world have used Si-SiC INEX composite tubes for over eight years.
Processes have included:
-
Annealing
-
Carburizing
-
Carbide Solution Treating
-
Neutral Hardening
-
Carbo-Nitriding
-
Ferriticnitrocarburizing
|
Furnace Atmospheres have included:
-
Endothermic (both lean and rich)
-
Carbon Enriched Gasses
-
Ammonia Enriched Gasses
-
Nitrogen
-
Mixed Endothermic/Ammonia (50/50)
|
Standard INEX Tube Sizes
|
O.D.
|
Wall thickness
|
I.D.
|
Available Length
|
|
1" (25.4mm)
|
1/8" (3.2mm)
|
3/4" (~19mm)
|
36" (914.4mm)
|
|
2-3/8" (60.3mm)
|
1/8" (3.2mm)
|
2-1/8" (~53.9mm)
|
70" (1778mm)
|
|
2-3/4" (70mm)
|
1/8" (3.2mm)
|
2-1/2" (~63.6mm)
|
70" (1778mm)
|
|
3-1/4" (82.5mm)
|
1/8" (3.2mm)
|
3" (~76.1mm)
|
72" (1828.8 mm)
|
|
4-1/2" (114.3mm)
|
3/16" (4.8mm)
|
4-1/8" (~104.7mm)
|
96" (2438.4 mm)
|
|
5-1/8" (130.2mm)
|
3/16" (4.8mm)
|
4-3/4" (~120.6mm)
|
60" (1524 mm)
|
* Larger sizes are under development. Special customer requirements
concerning size, length or wall thickness can be quoted.
Configurations of Composite Radiant tube (CRT)
|
|
Plugged end, and end with a flange |
If you have any questions, please contact C.T. Kang, Ph.D.
e-mail: 7si@7-stars-international.com
P.O. Box 512, Richland, WA 99352 USA
Tel: (509)946-2495, Fax: (509)943-9235
Products
You can hyperlink to the following web pages and find more information
about these products which are handled by Seven Stars International, LLC.
Advanced Refractory Technologies (ART)
Diamond Coating Maching -- Diamond Zone 800 (Chinese Big 5), 
Chinese
GB Code
Special Nozzles for Sandblasting, Spray Drying
and Geo Jet
Odor Control Company, Inc. (Chinese
Big 5), Chinese
GB Code
Electrical Conductive Sintered Alpha Silicon
Carbide Components: Manufactured by Standard Ceramics, Inc.
Boron Carbide, B4C: Properties, applications
and products of boron carbide
Boron Carbide Nozzles and Inserts:
Advantages and product information of boron carbide nozzles and inserts.
Both nozzles and insert are produced by Malyn Industrial Ceramics, Inc..
Boriding Agents: Properties, applications
of two boriding agents
Schunk-Inex Si / SiC Composite Radiant Tube:
High temperature Si/SiC composite radiant / protective tubes for heat treatment
industry
Schunk-Inex Si / SiC Tube (Chinese
Big 5), Chinese
GB Code
Information about INEX Si/SiC tubes written in Chinese.
MCrAlY Coatings: High temperature corrosion resistant coatings
Mechanical Seals and Seal
Rings: Seal ring materials include: reaction bonded SiC, tungsten
carbide, alumina and silicon nitride.
Boron Nitride, BN: Properties, applications
and products of boron nitride powders
MoSi2 Heating Element
SiC: Properties, applications and products
of silicon carbide
Zirconia Powders: Information of two
available.ZrO2 powders
Back to Index Page
Other Links
Thermal spray related links: List of
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coatings
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