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.

Formic acid, HCOOH
Conc. HCOOH%0.5112225555
Temp. °C7020402040100208095100=BP
Grade or type of alloy:
Carbon steel2222222222
13 Cr0222222222
Alleima® 18020000000000
Alleima® 3R120000010122
Alleima® 3R600000000011
18Cr13Ni3Mo 1)
17Cr14Ni4Mo 2)
Alleima® 2RK65 ('904L')0000000000
Sanicro® 280000000000
254 SMO0000000000
654 SMO0000000000
SAF™ 23040000000000
SAF™ 22050000000000
SAF™ 25070000000000
Titanium (CP Ti)0000000000

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

Formic acid, HCOOH
Temp. °C206090101=BP208090100205070801006010020
Grade or type of alloy:
Carbon steel2222222222222222
13 Cr2222222222222222
Alleima® 18020000000000002020
Alleima® 3R120122022201222220
Alleima® 3R600011001100001010
18Cr13Ni3Mo 1)
17Cr14Ni4Mo 2)
Alleima® 2RK65 ('904L')0000000100001010
Sanicro® 28000000100000010
254 SMO0000001000011
654 SMO000000000000000
SAF™ 23040001002000220
SAF™ 220500000010000010
SAF™ 25070000000000000000
Titanium (CP Ti)0000000100002010

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

Formic acid, HCOOH
Conc. HCOOH %80909090909090100100100
Temp. °C107 =BP20406080100106 =BP2060101 =BP
Grade or type of alloy:
Carbon steel2222222122
13 Cr2122222112
Alleima® 18022000022000
Alleima® 3R122001222001
Alleima® 3R601000012001
18Cr13Ni3Mo 1)
17Cr14Ni4Mo 2)
Alleima® 2RK65 ('904L')1000011000
Sanicro® 281000011000
254 SMO100001000
654 SMO1000000000
SAF™ 23042000021
SAF™ 220510000021
SAF™ 25071000001001
Titanium (CP Ti)1000011001
SAF™ 29061011
SAF™ 2707 HD1
SAF™ 3207 HD1011

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.