NANMAC's
NC-11 metal-ceramic protection tube is
a hard, abrasion-resistant, dense material made from two
high temperature compatible materials. The combination of
this high temperature metal and oxide produces a product
with three very important properties:
.
Superior oxidation resistance to 2500°F
. Thermal
conductivity comparable to that of stainless steel
. Good
resistance to wetting by most molten metals
NC-11
has good strength at temperatures where many high-temperature
metals melt. Above about 2800°F, it begins to soften
and becomes plastic. NC-11 Thermocouple protection tubes
have however, been used successfully for dip immersion at
a temperature of 3000°F. In use or service, care must
be taken to avoid conditions of extreme thermal shock, extreme
thermal gradients, mechanical shock, and impact. Although
NC-11 is superior to ceramics in all of these properties,
It Is less resistant to shock and impact than the metallic
alloys. Therefore, it should be preheated to about 900F
before immersion in molten metal at 2000°F or higher.
Whenever practical, the following preheat procedure can
also be used. Hold the tube immediately above the molten
steel for approximately one minute before immersing.
Information
about corrosion resistance and melting points of different
materials can be found in the Resource Center.
APPLICATIONS
.
Molten copper and brass to 21001 Deg. F intermittent and
continuous immersions,
. Corrosive
SO and SO gas (to 2500 Deg. F) and SO and HP gas (to 2000°F]
. Open
hearth furnace checker chambers to 2450°F
. Pelletizing
chamber of Taconite refining operation to 2100°F
. Molten
zinc to 1600°F
. Molten
lead to 650°F
. Basic
steel and slags to 3150°F (intermittent) and 2500°F
(continuous in open hearth and general foundry practices).
. Fluid
bed cement process with severe corrosion and temperature
to 2400°F (fluid method of producing builders cement).
NC-11
is not recommended for use in molten aluminum, molten glass,
or carbide slags. Special probes have been designed for
use with molten aluminum which provide
long term use.
