CORROSION RESISTANCE OF HASTEllOY®AllOYS - Haynes ...
CORROSION RESISTANCE OF HASTEllOY®AllOYS - Haynes ...
CORROSION RESISTANCE OF HASTEllOY®AllOYS - Haynes ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
PHOSPHORIC ACID<br />
ISO<strong>CORROSION</strong> DIAGRAMS·<br />
HASTELLOY® alloys B-2, C-276, C-22, G-3, G-30 and HAYNES® alloy No. 25<br />
have acceptable corrosion resistance at most concentrations and<br />
temperatures. The maximum rates were observed in boiling 85 percent acid for<br />
all of these alloys.<br />
Commercial grades of phosphoric acid encountered during the<br />
production of wet process or superphosphoric acid quite frequently contain<br />
numerous impurities. These impurities, basically fluorides and ferric salts,<br />
serve to change the basic character of the acid. Alloys G-3 and G-30 have<br />
demonstrated excellent resistance to wide variety of acid compositions,<br />
presumably because of their high chromium contents.<br />
HASTELLOY® Alloy B-2<br />
Resistance to Phosphoric Acid<br />
350.-------,,-----,-------r-----r---,----.----,-------.-------,<br />
u..<br />
300<br />
<br />
l-<br />
75<br />
e:{<br />
a:<br />
w<br />
0....<br />
2 w<br />
I-<br />
50<br />
0<br />
10<br />
20 30 40 50 60<br />
CONCENTRATION, WEIGHT PERCENT<br />
70<br />
80<br />
HASTELLOY® Alloy C-276<br />
Resistance to Phosphoric Acid<br />
350.-------r-------r----,----,----.----,-------.------,------,<br />
Corrosion rates in parentheses are in mm/year.<br />
u..<br />
300<br />
<br />
l- e:{<br />
a:<br />
w<br />
0....<br />
2 w<br />
I-<br />
50<br />
100<br />
o 10 20 30 40 50 60<br />
CONCENTRATION. WEIGHT PERCENT<br />
•All test specimens were solution heat-treated and in the unwelded condition.<br />
71