Corrosion Resistance of Welds
To assess the resistance of welds to corrosion, Haynes International has chosen to test all-weld-metal samples, taken from the quadrants of cruciform assemblies, created using multiple gas metal arc (MIG) weld passes. Notably, the resistance of all-weld-metal samples of G-30 alloy to key, inorganic acids is close to that of the wrought, base metal in several cases.
| Chemical
|
Concentration
|
Temperature
|
Corrosion Rate
|
| wt.%
|
°F
|
°C
|
Weld Metal
|
Wrought Base Metal
|
| mpy
|
mm/y
|
mpy
|
mm/y
|
| H2SO4 |
30 |
150 |
66 |
<0.4 |
<0.01 |
<0.4 |
<0.01 |
| H2SO4 |
50 |
150 |
66 |
0.4 |
0.01 |
0.4 |
0.01 |
| H2SO4 |
70 |
150 |
66 |
5.5 |
0.14 |
4.3 |
0.11 |
| H2SO4 |
90 |
150 |
66 |
102.4 |
2.60 |
102.8 |
2.61 |
| HCl |
5 |
100 |
38 |
<0.4 |
<0.01 |
13.0 |
0.33 |
| HCl |
10 |
100 |
38 |
27.6 |
0.70 |
17.3 |
0.44 |
| HCl |
15 |
100 |
38 |
25.2 |
0.64 |
26.0 |
0.66 |
| HCl |
20 |
100 |
38 |
20.5 |
0.52 |
11.8 |
0.30 |
| HNO3 |
70 |
Boiling |
5.5 |
0.14 |
5.5 |
0.14 |