Nickel Insitute - Nickel Alloys in Organic Acids & Related Compounds

Process facilities for handling formic acid are normally constructed of Type 316L stainless steel, copper, or the cupro-nickels. Data obtained by the exposure of alloys in a formic acid distillation column are shown in Table XXVIII. Other data generated by the testing of alloys in a 90% formic acid still are contained in the reference NACE report. 25 Depending on the acid concentration, the type of

contaminants present in the acid, the temperature of the system and the type of cooling water used, it is not unique to find a distillation column and accessories to be con- structed of a combination of Type 316L stainless steel, C70600 (90-10 cupro-nickel), ACI CN-7M castings and HASTELLOY alloy C-276. Other materials combinations are obviously possible from a perusual of the data, but

TABLE XXXVII

Corrosion by Formic Acid Under Heat Transfer Conditions

Temperature

Corrosion Rate

Formic Acid Test Medium

Without

With Heat Transfer*

Type 304 Stainless Steel

Type 316 Stainless Steel

CARPENTER alloy 20Cb-3

HASTELLOY alloy B

INCONEL alloy 600

MONEL alloy 400

Heat Transfer

ºC

ºF

ºC

ºF

mm/y

mpy

mm/y

mpy

mm/y

mpy

mm/y mpy mm/y mpy mm/y

mpy

10% aqueous 101

214

–

–

18.85 742 >25.4 >1000 14.48 570 14.48 570 >25.4 >1000 >25.4 >1000 >25.4 >1000 >25.4 >1000 18.19 716 13.72 540 12.7 500 13.21 520

.25 .41

10 16

<.03

<1

.25

10 50

.89

35 73

3.38

133

–

–

110

230

.05

2

1.27

1.85

16.26 640 >25.4 >1000 >25.4 >1000 2.21 87 1.93 76 1.22 48 2.54 100 .03 1 .56 22 .84 33 1.27 50

–

–

125

257

1.57

62

.20

8

1.42

56

1.68

66

–

–

140

284

1.85

73

.69

27

2.03

80

1.52

60

50% aqueous 103

217

–

–

.99

39

.15

6

.28

11

1.55

61

–

–

110

230

1.47

58

.23

9

.23

9

1.93

76

–

–

125

257

1.52

60

.33

13

.13

5

3.30

130

–

–

140

284

2.13

84

.31

12

113

5

2.92

115

89% aqueous 103

217

–

–

.25

10

.13

5

<.03

<1

1.02

40

–

–

110

230

1.22

48

.10

4

.13

5

1.27

50

–

–

125

257

1.02

40

.15

6

.08

3

1.93

76

–

–

140

284

1.22

48

.25

10

.18

7

1.42

56

*Metal temperature. Reference 10. See that publication for apparatus and technique used

TABLE XXXVIII

Corrosion of Alloys in Formic Acid at High Temperatures

(Tests conducted in sealed pressure tubes)

% Formic Acid Test Period, days

1 1

2* 27

4.6 1

24 1

Test Temperature

Corrosion Rate

ºC

ºF

mm/y

mpy

mm/y

mpy

mm/y

mpy

mm/y

mpy

Alloy

Type 410 stainless steel Type 430 stainless steel Type 446 stainless steel Type 304 stainless steel

170 170 170 150 170 170 100 150 170 200 150 170 170 170 150 170 150 170 150 170 150 150 170 170 170

338 338 338 302 338 338 212 302 338 392 302 338 338 338 302 338 302 338 302 338 302 302 338 338 338 338

– – – – – – – – – – – – – – – – – – – – – – –

– – – – – – – 5 8 – – – – – – – – – – – – – – – –

– – – – – –

– – – – – – 4 – – 2 – – – 3 – 1 – 1 – 1 1 – – – –

16.26 10.41

640 410

– – – – – –

– – – – – –

.66

26

.46

18

–

–

3.56 2.36

140

Type 310 stainless steel Type 316 stainless steel

93 23 60 72 66

.58

1.04 3.05

41

.13 .20 .89

.10

1.52 1.83 1.68

120

– –

–

–

35

3.30

130

Type 317 stainless steel

.05

–

–

– – – – – – – – – – – – – – – –

– – – – – – – – – – – – – – – –

– – –

1.60

63

HASTELLOY alloy C HASTELLOY alloy B INCONEL alloy 600

.10 .23

4 9

.08

–

–

–

3.30

130

Nickel 200

.03

–

–

–

2.34

92

MONEL alloy 400

.03

–

–

–

.89

35

C71500 (70-30 Cupro-nickel)

.03 .03

– –

– –

Copper

– – – –

.20 .15

8 6

Silver

Aluminum1100

10.16

400 290

DURIRON

170

7.37

Reference 24

*Also contained 1.5% formaldehyde.

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