Thomas J.C. Eun
Intergranular Corrosion (IGC) Test for ASS
ASTM A262A262-2008 (1/4)
Practice A
Practice B
(Streicher Test)
Practice C
(Huey Test)
Practice E
(Strauss Test)
Practice F
Test Name
Oxalic Acid**
Etch Test
- Etching Test
Ferric SulfateSulfuric Acid Test
- Immersion Test
65% Nitric Acid Test
- Immersion Test
Copper-Copper Sulfate16% Sulfuric Acid Test
- Immersion Test
Copper-Copper
Sulfate-50%
Sulfuric Acid Test
- Immersion Test
Solution
Temperatue,
Exposure
Time
4 to 240 Hrs
24 to 120 Hrs in
boiling solution
240 Hrs in boiling solution, boiled for
five periods, each of 48 hours.
15 Hrs in boiling
solution. The specimen
to be bent through 180°°
and over a diameter
equal to the thickness of
the specimen being bent.
boiling solution
Detecting
TargetMaterials
- Cr-Carbides
; 201, 202, 301,
304, 304L*,
304H, 316,
316L*, 316H,
317, 317L*, 321*,
347*, CF-3, CF-8,
CF-3M, CF-8M
- Cr-Carbides
; 304, 304L, 316,
316L, 317, 317L,
CF-3, CF-8
-Cr-Carbides &
σ Phase
; 321, CF-3M, CF8M
- Cr-Carbides
; 304, 304L, CF-3, CF-8, 309, 310, 348
- Cr-Carbides & σ Phase (must be
when destined for service in nitric acid)
; 316, 316L, 317, 317L, 321, 347, CF3M, CF-8M
- End-grain pitting
; All grades
- Cr-Carbides
; 201, 202, 301, 304,
304L, 316, 316L, 317,
317L, 321, 347
- Cr-Carbides
; CF-3M, CF-8M
Test
Purpose
To determine
essentially free of
Cr-carbides
sensitization to
inter granular
attack associated with Crcarbide
participates.
To measure the
susceptibility to
inter granular
attack associated
with the
precipitation of Crcarbides at
grain boundaries
-Mainly be used as a check on whether
the material has been correctly heat
treated.
-Also be used for materials that come
into contact with strongly oxidizing
agents, e.g. nitric acid.
-Also be used to check the effectiveness
of stabilizing elements and of
reductions in C content in reducing
susceptibility to inter granular attack.
To determine
susceptibility to inter
granular attack
associated with the
precipitation
of Cr-rich carbides
To measure
susceptibility of "as
received" stainless
steels to inter
granular attack.
79
Intergranular Corrosion (IGC) Test for ASS
ASTM A262A262-2008 (2/4)
Practice A
Practice B
(Streicher Test)
Practice C
(Huey Test)
Practice E
(Strauss Test)
Determination
or
Acceptan
ce
Category
- No quantitative
results
- Be used for
acceptance but
not rejection of
material.
- See Fig. 1
thru 7.
- Corrosion rate
from weight loss
determinations
- See Table 3 for
rapid screening
per Practice A
(except 321, 347 –
Cb, Ti contained
SS)
- Corrosion rate during each
boiling period is calculated from
the decrease in the weight of the
specimens.
- See Table 4 for rapid screening
per Practice A (except 316,
316L,
317, 317L, 321, 347-Mo, Cb, Ti
contained SS)
- Visual examination of
the bent specimen.
- No quantitative results
- See Table 5 for rapid
screening per Practice
A
- See Fig.11 thru 13.
Alternatives/
Test
Specimen
- May be used
to a rapid
method screen
specimens
intended for
testing in
other practices
** 10%
(NH4)2S2O8
solution
Notes for
Test
Requirements/
Condition
* after
sensitizing HT
at 1200-1250F,
1 Hr
Practice F
Corrosion
rate from
weight loss
determination
The purchaser must specify the
maximum permissible corrosion
rate and, in applicable cases,
data on sensitizing HT.
80
Intergranular Corrosion (IGC) Test for ASS
ASTM A262A262-2008 (3/4)
81
Intergranular Corrosion (IGC) Test for ASS
ASTM A262A262-2008 (4/4)
Fig. 11 Passing Test Specimen – View of Bent Ares
(x 20 before reproduction)
Fig. 13 Doubleful Test Result – Traces of intergranular
Fig. 12 Falling Test Specimen – Many intergranular fissues
fissues and orangeorange-peel surface (x 20 before reproduction)
(x 20 before reproduction)
82