Page 3 - SD 2507Cu
P. 3
Heat treatment :
SD 2507Cu is delivered in the solution annealed and water quenched conditions
(1080/1120°C - 1976/2018°F). The chemical analysis and heat treatment are
optimised in order to reach a 50% / 50% microstructure.
CORROSION General corrosion
RESISTANCE
SD 2507Cu performs particularly well in sulphuric and phosphoric acid solutions,
even in presence of chlorides. The duplex microstructure which provides high
mechanical properties explains why the alloy behaves particularly well in abrasion-
corrosion conditions (agitators, screws, rakes...).
Mixed acids are often associated with chlorides and in pollution control
equipments. Due to high chromium, molybdenum and copper additions, SD 2507Cu
behaves well in scrubber systems. In Pulp and Paper industries, SD 2507Cu is
used in the most severe conditions encountered for example in digester (resistant
to hot wall problems), chips presteaming vessels or in some bleaching equipments.
Corrosion rate
mg/dm²/24 h
Boiling curve 80°C (176°F)
100 212 85°C (185°F)
100
80 176
Temperature (°C) 60 N08904 S32520 140 Temperature (°F) 10
40 316 N08926 104
S31803
+
316 URB6 UR52N UR47N UNS UR52N +
904L S32550 S32750 S32760 S32550
20 68 Corrosion rate in 10% H2SO4 + 500 ppm Cl -
0 20 40 60 80 100
H 2SO 4 (% wt) aerated, at 80°C and 85°C (176°F and 185°F)
Medium : NaCl 30g/l + Fe 2 (SO 4 )3 0,1 % - pH = 2 aerated Medium : P205 : 30% - H2SO4 : 2% - F- 0,2% - H2SiF6 1,5%
Corrrosion rate T = 60°C Test duration 15 days Fe3 + 0.35% - Al3 + 0.26%
(mdd) Corrosion rate (mdd)
100
3 00 - 80°C (176°F)
0 ppm F
1000 ppm F - 80 110°C (230°F)
2 00 60
40
1 00
20
No 0
0 Corrosion UR B6 SD 2507Cu UR B28 UR SB8
316L 317LNM UR45N N08904 UR 52N N 08904 S32550 N 08028 N08932
Pollution control equipments Phosphoric acid production
Effects of fluoride contents on the uniform corrosion rate Effect of the attack temperature on the corrosion rate
Chloride
concentration (ppm) Corrosion rate
(mdd)
2000 UR 52N + 8 0
White liquor :
1600 7 0 NaOH : 125 g/l
UR B6 6 0 Na 2S : 50 g/ll
1200 UR 45N 5 0 Na 2/So 4 : 16 g/l
Na 2CO 3 : 27 g/l
317 LNM 4 0 Sulfidity : 21 %
800 317 LN 304L H2S bubbling
316 LN 3 0 316L
400 316L 2 0
1 0
UR 45N +
20 60 80 120 (°C) 0 UR 52N
40 60 80 100
68 140 176 216 (°F) 20 Chloride concentration (g/l)
Safe use limits of stainless steels versus Heat transfer (solution 140°C - Sample 80°C)
chloride content and temperature in 54 % P205 Pulp and Paper industry
Corrosion rate versus chloride content in Kraft media
