These corrosion data are mainly based on results of general corrosion laboratory tests, carried out with pure chemicals and water solutions nearly saturated with air (the corrosion rate can be quite different if the solution is free from oxygen).

All concentrations are given in weight-% and the solvent is water if nothing else is shown. The corrosion data apply to annealed materials with normal microstructure and clean surfaces, throughout.

Nitric acid, HNO3 + sulphuric acid, H2SO4
Conc. HNO3 %333
Conc. H2SO4 %551010179599101050
Temp. °C255025801005035258025
Grade or type of alloy:
Carbon steel
13 Cr
Alleima® 1802
Alleima® 3R120001110010
Alleima® 3R60000000000
18Cr13Ni3Mo 1)
000000000
17Cr14Ni4Mo 2)
000000000
Alleima® 2RK65 ('904L')000000000
Sanicro® 28
254 SMO
654 SMO
SAF™ 2304
SAF™ 2205
SAF™ 2507011221010
Titanium (CP Ti)

1) ASTM 317L, e.g. Alleima® 3R64
2) EN 1.4439, e.g. Alleima® 3R68

Nitric acid, HNO3 + sulphuric acid, H2SO4
Conc. HNO3%55555710101010132020202530
Conc.H2SO4%20206060601760608090168080801520
Temp. °C255025508010060805035100206010010080
Grade or type of alloy:
Carbon steel22
13 Cr221
Alleima® 180201
Alleima® 3R12000000100001101
Alleima® 3R600000101000010
18Cr13Ni3Mo 1)
0000101000010
17Cr14Ni4Mo 2)
0000101000010
Alleima® 2RK65 ('904L')0000101000010
Sanicro® 2800
254 SMO
654 SMO
SAF™ 230400
SAF™ 220500
SAF™ 250700
Titanium (CP Ti)000021212221

1) ASTM 317L, e.g. Alleima® 3R64
2) EN 1.4439, e.g. Alleima® 3R68

Nitric acid, HNO3 + sulphuric acid, H2SO4
Conc. HNO3 %3030475050545454566590
Conc. H2SO4 %4070142050676795143510
Temp. °C8035100806075BP601003535
Grade or type of alloy:
Carbon steel2
13 Cr1
Alleima® 180210
Alleima® 3R1210011021000
Alleima® 3R60101100
18Cr13Ni3Mo 1)
101000
17Cr14Ni4Mo 2)
101000
Alleima® 2RK65 ('904L')100000
Sanicro® 2800
254 SMO0
654 SMO
SAF™ 230400
SAF™ 220500
SAF™ 250700
Titanium (CP Ti)111000

1) ASTM 317L, e.g. Alleima® 3R64
2) EN 1.4439, e.g. Alleima® 3R68

Symbol clarification

These corrosion tables use a number of symbols, having the following meanings:

Symbol Description
0 Corrosion rate less than 0.1 mm/year. The material is corrosion proof.
1 Corrosion rate 0.1—1.0 mm/year. The material is not corrosion proof, but useful in certain cases.
2 Corrosion rate over 1.0 mm/year. Serious corrosion. The material is not usable.
p, P Risk (severe risk) of pitting and crevice corrosion.
c, C Risk (Severe risk) of crevice corrosion. Used when there is a risk of localised corrosion only if crevices are present. Under more severe conditions, when there is also a risk of pitting corrosion, the symbols p or P are used instead.
s, S Risk (Severe risk) of stress corrosion cracking.
ig Risk of intergranular corrosion.
BP Boiling solution.
ND No data. (Used only where there are no actual data to estimate the risk of localised corrosion instead of p or s).

Disclaimer: Laboratory tests are not strictly comparable with actual service conditions. Accordingly, Alleima makes no warranties, express or implied, and accept no liability, compensatory or consequential, for the performance of different materials in individual applications that may be based on the information provided in this publication.