Resistance to Pitting and Crevice Corrosion

HAYNES® 625 alloy exhibits good resistance to chloride-induced pitting and crevice attack, forms of corrosion to which some of the austenitic stainless steels are particularly prone. To assess the resistance of alloys to pitting and crevice attack, it is customary to measure their Critical Pitting Temperatures and Critical Crevice Temperatures in acidified 6 wt.% ferric chloride, in accordance with the procedures defined in ASTM Standard G 48. These values represent the lowest temperatures at which pitting and crevice attack are encountered in this solution, within 72 hours.

Alloy Critical Pitting Temperature Critical Crevice Temperature
in Acidified 6% FeCl3 in Acidified 6% FeCl3
°F °C °F °C
316L 59 15 32 0
254SMO 140 60 86 30
28 113 45 64 17.5
31 163 72.5 109 42.5
G-30® 154 67.5 100 37.5
G-35® 203 95 113 45
625 212 100 104 40
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