Premium
Corrosion behavior of nickel alloys in wet hydrofluoric acid
Author(s) -
Rebak R. B.,
Dillman J. R.,
Crook P.,
Shawber C. V. V.
Publication year - 2001
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/1521-4176(200104)52:4<289::aid-maco289>3.0.co;2-0
Subject(s) - corrosion , alloy , hydrofluoric acid , metallurgy , nickel , materials science , penetration (warfare) , penetration rate , intergranular corrosion , nuclear chemistry , chemistry , geotechnical engineering , operations research , engineering
Wet hydrofluoric acid at concentrations below approximately 60% is highly corrosive to glass, reactive metals, carbon steel and stainless steels. Nickel alloys offer moderate corrosion resistance over a wide range of acid concentration and temperature. The corrosion behavior of eleven commercial alloys was quantified through laboratory testing. Variables that were studied included testing time, acid concentration, temperature, vapor and liquid phases and the presence of residual stresses. Results show that the corrosion rate of a Ni‐Cu and a Ni‐Cr‐Mo‐Cu alloy increased with the acid concentration and the temperature. However, both for increasing acid concentration and temperature, the corrosion rate of the Ni‐Cu alloy increased faster than the corrosion rate of the Ni‐Cr‐Mo‐Cu alloy, especially in the vapor phase. Even in unstressed coupons, nickel alloys showed internal penetration in presence of wet HF; the mode of this internal penetration varied from alloy to alloy. Considering all the studied variables that influence corrosion, the highest ranked material for wet HF service was a Ni‐Cr‐Mo‐Cu alloy.