316 L seal crevice corrosion?
316 L seal crevice corrosion?
(OP)
It is well known that in stagnant seawater 316 may be unsatisfactory for piping. However, if I have a 316 L seal with Inconel inlay on the ring groove, will the 316 L seal has the same risk of the crevice corrosion?





RE: 316 L seal crevice corrosion?
This kind of arrangement is common, but in this case you may be building up problems for yourself, with even a slight galvanic effects making things worst. If you've got the cash suggest Inconel seal rings and sleep safe at night!
RE: 316 L seal crevice corrosion?
The equipment is 25 meters under seawater inside a steel basket. So I would suspect it is stagnant seawater all the time. The body consists two pieces connected using flange. The concern is the seal which is 316L. The mating pieces are low alloy CS with TSA coating. What is your suggestion?
RE: 316 L seal crevice corrosion?
RE: 316 L seal crevice corrosion?
I have to have sound the justification for the change. Crevice corrosion of the 316L in the stagnant seawater? Do you know any historical data or regulatary info about it? Any website?
RE: 316 L seal crevice corrosion?
RE: 316 L seal crevice corrosion?
Example: 316L with 0.5% nitrogen showed no pitting, but has about double 0.2%YS and TS.
With 1.0% nitrogen, no Ni was required to get the metallurgical structure of completely austenite. This no nickel austenitic stainless steel was formed to a very small pipe to be used as catheter for the patients with nickel allergy. For these materials several melting and refining processes were developed under Japanese government funding.
Consultant
T. Sekine
Tokyo, Japan
tomosekine@jcom.home.ne.jp
RE: 316 L seal crevice corrosion?
You mention Inconel, however, there are several varieties of inconel. Hopefully, yours is Inconel 625 which has 9% molybdenum and has good resistance to seawater. If it is Inconel 600 (No Moly), or other low molybdenum containing Inconel grades then it will be no better in resisting crevice corrosion than 316L stainless.
RE: 316 L seal crevice corrosion?
Regards,
Mekanikeren