COMPOSITION OF STAINLESS STEELS TESTED Chemical Analysis (% weight)PRENW CrNiMoCuWN(1) 0,0525 0,1734...
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Transcript of COMPOSITION OF STAINLESS STEELS TESTED Chemical Analysis (% weight)PRENW CrNiMoCuWN(1) 0,0525 0,1734...
COMPOSITION OF STAINLESS STEELS TESTED
Chemical Analysis (% weight) PRENWCr Ni Mo Cu W N (1)
0,05 25
0,17 34
0,25 410,28 41
0,20 43
0,5 0,48 56
0,07 38
17,2
22
2524,9
19,9
24,5
26,7
24,5
2,6
3,2
3,63,8
6,0
7,3
3,4
4,7
1,50,7
0,4
0,9
1,5 0,40 54
316L
31803
3252032750
31254
32654
08028
08932
08926
TradeName
UR52N+SAF2507
254SMO
654SMO
SAN 28
URB66
URB26 20
12,6
5,5
6,36,9
17,8
21,8
30,3
22
24,7 6,3 0,8 0,19 43
UNS
SAF2205
AISI
PRENW : Cr + 3.3 Mo +1.6 W + 16 N
2
PITTING CORROSION RESISTANCE NaCl 30 g/l - ASTM G61
URB66
316L
N08926
20 30 40 50 60 70 80 90 100
200
400
600
800
1000
0
Temperature, °C
Pitti
ng P
oten
tial,
mV/
SCE N06 622
304L
UR45N
S 31726
32 520904L
LONG TERM IMMERSION TESTINGin
NATURAL SEA WATER(Crevice Corrosion)
REST POTENTIAL OF MCW SAMPLES in MEDITERRANEAN SEA
100 2000-
Crevice Corrosion
32550, 08926, URB66 :No Crevice Cor
08904
- 400
0
+400R
est P
oten
tial,
mV/
Ag-
AgC
l
31803
31603
30403
Time, Days
MCW : multi crevice washers
EFFECT OF CLIMATIC CONDITIONSPRENW > 40 :UR52N+, URB26, URB66 (MCW samples):
no Crevice Corrosion+400
0
-400100 2000
Res
t Pot
entia
l, m
V/A
g-A
gCl
Time, days
Mediterranean Sea, FNorth Sea, N
Atlantic Sea, F
316LCrevice
PREN > 40no corrosion
CREVICE CORROSION in NATURAL SEA WATER
SteelG C B K T
Italy France France Sweden Norway
316L 5/5 5/5 0/4 0/4 4/4
31803 ++ + + 0/5 +
32520 + + 0/5 0/5 +
32750 0/4 + 0/5 + +
31254 + + 0/5 0/5 0/5
32654 + 0/5 0/5 + 0/4
08028 + + + 0/5 +
08926 0/5 0/5 0/5 + 0/5
+/++ one/several depassivated area, no weight loss5/5 crevice corrosion on 5 coupons out of 5
Winter + Summer immersion tests , 3000 hours each
MATERIAL SELECTION FOR SEAWATER SERVICE
Free Cl2 (ppm) 0 0.5 1 0 0.5 1 0 0.5 1 0 0.5 1
10
20T(°C)
30
40
TITANIUM
UR B66 S31266
UR B66 - S31266
URB26/08926UR 52N+/S32 520
Stagnant Flange with Washer (1)> 1 m/s Threaded Joint (2)
No fitting nor Crevice geometry Crevice Geometry
If some fretting or wear is involved, the material selectionhas to be adapted (please, contact corrosion specialists)
UR B26/N08926or
UR 52N+/S32520
UR
45N
- S
3180
3
S
32
205
316Lor
UR 45NUR B26/N08926
orUR 52N+/S32 520
Water velocity
(1) (2)