(4) H3P04
In phosphoric acid, (4) H3P04. In phosphoric acid, 0Mo28Ni65Fe5 alloy is resistant to H3P04 corrosion
Corrosion, 0Mo28Ni65Fe5 alloy corrosion resistance slightly decreased in addition to filling air and pressurized high temperature
Low, its H3P04 resistance is good. However, 0Mo28Ni65Fe5 (HastelloyB) alloy is not resistant to corrosion by wet method H3P04 because the acid contains hydrofluoric acid, fluorosilicic acid, residual sulfuric acid, and iron and aluminum salts, which are oxidized in nature.
Corrosion of 0Mo28Ni65Fe5 (HastelloyB) alloy Figure 7-17 Corrosion rate of 0 elbow 02_6 claw 5 alloy in ^04
The speed can be up to 25mm/a.
Table 7-19 Corrosion resistance of Hastelloy B (0Mo28Ni65Fe5) alloy in high temperature and high concentration H3P04
| Acid concentration/% |
Temperature/℃ |
test hour/H |
Corrosion rate |
||
|
H3P04 |
P203 |
Type of acid used |
/mm•a1 |
||
|
78-85 |
50-60 |
115 |
Chemically pure |
0. 130 |
|
|
80 |
57 |
138 |
15天 |
Industrial purity |
0. 2375 |
|
85 |
60 |
121 |
72 |
Pure reagent |
0.025 |
|
85 |
60 |
150 |
72 |
Pure reagent |
0.375 |
|
86 |
61 |
110 |
96 |
Chemically pure |
0. 100 |
|
87 ~90 |
62 -64 |
90 |
102days |
Industrial purity |
0. 075 |
|
96 |
69 |
255 -288 |
73 |
Wet production |
1.00 |
|
98 |
70.3 |
93 |
29days |
Wet production |
0. 00075 |
|
98 |
70.3 |
150 |
29days |
Wet production |
0. 0326 |
|
100 |
71 |
176 |
72 |
Chemically pure |
0. 100 |
|
100 |
71 |
205 |
72 |
Chemically pure |
0. 250 |
|
105 |
75 |
115 |
Pure reagent |
0. 0025 |
|
|
117 |
85 |
232 -250 |
6days |
Industrial purity |
0.275 |
|
117 |
85 |
250 -255 |
6days |
Industrial purity |
0.525 |
Table 7-20 Corrosion resistance of 0Mo28Ni65Fe5(hastelloyB) alloy in certain concentrations of H3P04
|
H3P04 concentration/% |
corrosion rage/ mm•a1 |
||
| room temperature |
65℃ |
Boiling | |
|
10 |
0. 0076 |
0. 0508 |
0. 0254 |
|
30 |
0. 0076 |
0. 0203 |
0. 0762 |
|
50 |
0. 0025 |
0. 0076 |
0.0762 |
|
85 |
Microscale |
0. 0102 |
0.7112 |
(5) Organic acids. In acetic acid, the corrosion rate of hastelloyB alloy does not exceed 0.125~0.15mm/a under severe corrosive conditions, ie at the boiling temperature of unfilled air, in 10%~50% acetic acid. Of course, if there is air in the acetic acid, it will also accelerate the corrosion of the alloy. However, in pure high-concentration acetic acid or glacial acetic acid, the effect of air filling on the corrosion resistance of hastelloy B (0Mo28Ni65Fe5) alloy is small. When NaCl is added to acetic acid, a small amount of HCI acid is formed. Although the corrosion rate of hastelloy B (0Mo28Ni65Fe5) alloy is slightly improved, the effect of hastelloy B (0Mo28Ni65Fe5) alloy on hydrochloric acid is good, so the effect is not significant. The corrosion resistance of hastelloy B (0Mo28Ni65Fe5) alloy in acetic acid is shown in Table 7-21, and the corrosion resistance in some organic acids is shown in Table 7-22.
Table 7-21 Corrosion resistance of hastelloyB (0Mo28Ni65Fe5) alloy in acetic acid
|
CH3COOH concentration/% |
Temperature/℃ |
test hour/H |
corrosion rate / mm•a1 |
CH3COOH concentration/% |
Temperature/℃ |
test hour/H |
corrosion rate / mm•a1 |
|
10 |
room temperature |
24 |
0.0125 |
50 |
room temperature |
24 |
0. 0250 |
|
10 |
65 |
24 |
0.0175 |
50 |
65 |
24 |
0.0010 |
|
10 |
101 |
96 |
0. 0750 |
50 |
Boiling |
24 |
0. 1000 |
|
10 |
Boiling |
24 |
0. 1500 |
50 |
102 |
96 |
0.1250 |
|
20 |
100 |
325天 |
0. 0500 |
85 ~95 |
118 |
30天 |
0. 1250 |
|
99 |
room temperature |
24 |
0. 0025 |
99.6 |
118 |
96 |
<0.025 |
|
99 |
65 |
24 |
0. 0050 |
glacial acetic acid |
125 |
37天 |
0. 1075 |
|
99 |
Boiling |
24 |
0. 0125 |
glacial acetic acid |
357 |
73天 |
0.0175 |
In formic acid. This acid is more corrosive to Hastelloy B (0Mo28Ni65Fe5) alloy than acetic acid. The presence of oxidant in the air and acid also accelerates the corrosion of Hastelloy B (0Mo28Ni65Fe5) alloy. The test results are shown in Table 7-22.
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Post time: May-20-2019