18.08.2015   NUCLEAR CHEMICAL ENGINEERING

ZIRCONIUM AND HAFNIUM COMPOUNDS

1.4 Valence States

The principal valence of zirconium and hafnium is +4. Halides of valence +2 and +3 have been prepared, but they are of less practical importance as they disproportionate when heated and react with water in aqueous solution.

Table 7.4 Composition specifications for zirconium sponge and zirconium alloys

Sponge

Zirconium sponge

Ingots

Common name

Zircaloy-2

Zircaloy-4

Zr-2.5Nb

ASTM grade

R60001

R60802

R60804

R60901

ASTM specification

B349-73

B350-73

B350-73

B350-73

Maximum impurities, ppm by weight Aluminum 75

75

75

75

Boron

0.5

0.5

0.5

0.5

Cadmium

0.5

0.5

0.5

0.5

Carbon

250

270

270

270

Chlorine

1300

—

—

—

Chromium

200

See below

200

Cobalt

20

20

20

20

Copper

30

50

50

50

Hafnium

100

100

100

100

Hydrogen

—

25

25

25

Iron

1500

See below

1500

Manganese

50

50

50

50

Nickel

70

See below

70

70

Nitrogen

50

65

65

65

Oxygen

1400

To be specified in order

See below

Silicon

120

200

120

120

Titanium

50

50

50

50

Tungsten

50

100

100

100

Uranium

3.0

3.5

3.5

3.5

Alloying elements, w/o

Tin

1.20-1.70

1.20-1.70

—

Iron

0.07-0.20

0.18-0.24

—

Chromium

0.05-0.15

0.07-0.13

_

Nickel

0.03-0.08

<0.007

—

Iron + chromium + nickel

0.18-0.38

0.28-0.37

—

Niobium

—

—

2.40-2.80

Oxygen

—

0.09-0.13

Source: American Society for Testing and Materials, 1976 Annual Book of ASTMStandards: part 8, Nonferrous Metals-Nickel, Lead and Tin Alloys, Precious Metals, Primary Metals; Reactive Metals, ASTM, Philadelphia, 1976.