|
TABLE 3: CORROSION RATES OF TI AND ZR IN CHLORIDE
SALT SOLUTIONS
|
Chloride Salt
|
Concentration (%)
|
Temperature (°
C) |
Zirconium
Corrosion (mpy)
|
Titanium
Corrosion (mpy)
|
|
Aluminum |
5,
10, 25 |
35
— 100 |
<
1 |
---
|
| 10
|
150
|
---
|
1.3
|
| 40
|
Boiling
|
---
|
4300
|
|
Ammonium |
1,
10, Saturated |
35
— 100 |
<
1 |
---
|
| Saturated
|
100
|
---
|
nil
|
|
Calcium |
5,
10, 25 |
35
— 100 |
<
1 |
---
|
| 70
|
Boiling
|
<
1 |
nil
|
| 80
|
200
|
---
|
0.2
|
|
Cupric |
|
35
— Boiling |
>
50 |
---
|
| 55
|
Boiling
|
---
|
0.1
|
|
Ferric |
6
|
50
|
1.9
|
---
|
| 10
|
25
|
9.0
|
---
|
| 10
|
50
|
16
|
---
|
| 50
|
Boiling
|
---
|
0.7
|
| 50
|
150
|
---
|
0.1
|
|
Magnesium |
47
|
Boiling
|
<
1 |
---
|
| 42
|
Boiling
|
---
|
nil
|
|
Mercuric |
5,
10, Saturated |
35
— 100 |
<
1 |
---
|
| 55
|
Boiling
|
---
|
nil
|
|
Potassium |
Saturated
|
60
|
<
1 |
---
|
| 29
|
Boiling
|
---
|
0.1
|
|
Stannic |
5
|
100
|
<
1 |
---
|
| 24
|
Boiling
|
<
1 |
---
|
| 20
|
Boiling
|
---
|
0.3
|
|
Zinc |
5,
20 |
35
— Boiling |
<
1 |
---
|
| 70
|
Boiling
|
nil
|
---
|
| 20
|
150
|
---
|
0.2
|
| 75
|
Boiling
|
---
|
2.4
|
| 80
|
Boiling
|
---
|
81
|
In neutral chloride salt solutions,
zirconium and titanium are almost equally corrosion resistant.
This is true for sodium chloride, potassium chloride, and
seawater; however, there is one notable exception. Titanium
is more susceptible to crevice corrosion, as seen by test
results of the metals exposed to boiling seawater (Table 4).
This phenomenon may be explained by realizing that the local
environment within a crevice becomes more reducing over time;
therefore, since zirconiumÕs corrosion resistance is better
in a reducing chloride salt solution, it will not be affected
as the titanium is by crevice corrosion.
Three of Five 1
2 3 4
5
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