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Zirconium is resistant to corrosion in most organic and mineral acids, alkalis, and some molten salts. Its corrosion resistance comes from a tightly adhered, almost chemical inert oxide that protects the metal.
Other than the natural regeneration of oxide that occurs when oxygen is present, zirconium oxide can be formed or enhanced by anodizing or by heating in air, water, or steam.
Because Zirconium performs well in superheated water and is transparent to thermal neutrons, it has been used since the 1950's as cladding for nuclear fuels. It is still used in water-cooled nuclear reactors. Zirconium is also used in the chemical processing industry, flashbulbs and incendiary ordnance, and is a gettering material in sealed vacuum devices.
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| Zirc 702 |
CARBON
C |
IRON+CHROMIUM
Fe+Cr |
HYDROGEN
H |
HAFNIUM
Hf |
NITROGEN
N |
OXYGEN
O |
ZIRCONIUM+HAFNIUM
Zr+Hf |
| <= 0.05 |
<= 0.20 |
<= 0.0050 |
<= 4.5 |
<= 0.025 |
<= 0.16 |
99.2 to 100.0 |
The commercially pure grade, Zirc 702
is chosen for most applications because of its corrosion resistance.
| Zirc 705 |
CARBON
C |
IRON+CHROMIUM
Fe+Cr |
HYDROGEN
H |
HAFNIUM
Hf |
NITROGEN
N |
NIOBIUM
Nb |
OXYGEN
O |
ZIRCONIUM+HAFNIUM
Zr+Hf |
| <= 0.05 |
<= 0.20 |
<= 0.0050 |
<= 4.5 |
<= 0.025 |
2.0 to 3.0 |
<= 0.18 |
95.0 to 100.0 |
Alloyed with 2 to 3% Columbium, Zirc 705 is significantly stronger and more ductile than Zirc 702
with almost equal corrosion resistance. It is the alloy of choice for most zirconium fasteners.
| Zirc 706 |
CARBON
C |
IRON+CHROMIUM
Fe+Cr |
HYDROGEN
H |
HAFNIUM
Hf |
NITROGEN
N |
NIOBIUM
Nb |
OXYGEN
O |
ZIRCONIUM+HAFNIUM
Zr+Hf |
| <= 0.05 |
<= 0.20 |
<= 0.0050 |
<= 4.5 |
<= 0.025 |
2.0 to 3.0 |
<= 0.16 |
95.0 to 100.0 |
This alloy differs from Zirc 705 by having a lower oxygen content, that causes
lower tensile properties but greater elongation.
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