ASTM F1113-87(1999)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F1113–87(Reapproved1999)
Standard Test Method for
Electrochemical Measurement of Diffusible Hydrogen in
Steels (Barnacle Electrode)
This standard is issued under the fixed designation F1113; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Summary of Test Method
1.1 This test method describes the procedure for measuring 3.1 A hydrogen-containing part is made the anode in an
diffusible hydrogen in steels by an electrochemical method. electrochemical cell. The diffusible (atomic) hydrogen, which
1.2 This test method is limited to carbon or alloy steels, comes to the metal-electrolyte interface, is oxidized to protons
+ + −
excluding austenitic stainless steels. (H ); H combines with hydroxyl ions (OH ) in the electrolyte
1.3 This test method is limited to flat specimens to which toformwater.Theoxidationcurrentismeasuredandrelatedto
the cell can be attached (see 4.6 and 4.8). the hydrogen concentration.
1.4 Thistestmethoddescribestestingonbareorplatedsteel
4. Significance and Use
after the plate has been removed (see 4.4).
1.5 This test method is limited to measurements at room 4.1 The critical level of hydrogen in steels is that hydrogen
which can build up to high concentrations at points of high
temperature, 20 to 25°C (68 to 77°F).
1.6 This standard does not purport to address all of the triaxialstresscausingembrittlementofthesteelwhichcanlead
to catastrophic damage. This hydrogen can enter by various
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- means, such as during pickling and electroplating. Means of
reducing this hydrogen during processing are given in Speci-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. fication A165 and Practices B183 and B242. It is still
necessary, however, to know how effective these methods are.
2. Referenced Documents
Though the ultimate reason for measuring this hydrogen is to
2.1 ASTM Standards: relateittoembrittlement,thisisnotwithinthescopeofthistest
A165 Specification for Electrodeposited Coatings of Cad- method. As susceptibility to hydrogen embrittlement is a
mium on Steel function of alloy type, heat treatment, intended use,and so
B183 Practice for Preparation of Low-Carbon Steel for forth, the tolerance for hydrogen must be determined by the
Electroplating user according to Method F519.
B242 Practice for Preparation of High-Carbon Steel for 4.2 Though the actual hydrogen concentration is not deter-
Electroplating mined in this test method, the current densities have been
D1193 Specification for Reagent Water shown to be useful as an indication of relative hydrogen
F519 Test Method for Mechanical Hydrogen Embrittle- concentrations (1-3), and therefore the degree of hydrogen
mentEvaluationofPlatingProcessesandServiceEnviron- embrittlement (1,2). Thus, measurements can be compared to
ments one another (see 4.1 and 7.1).
G3 PracticeforConventionsApplicabletoElectrochemical 4.3 This test method is applicable as a quality control tool
Measurements in Corrosion Testing for processing (such as to monitor plating and baking) or to
measure hydrogen uptake caused by corrosion.
4.4 This test method is nondestructive; however, if there is
This test method is under the jurisdiction of ASTM Committee F-7 on
a coating, it must be removed by a method which has been
Aerospace andAircraft and is the direct responsibility of Subcommittee F07.04 on
demonstrated to neither damage the steel nor introduce hydro-
Hydrogen Embrittlement.
gen to make the measurement.
Current edition approved Dec. 31, 1987. Published April 1988.
Discontinued in 1988 and replaced by Specification B766.
Annual Book of ASTM Standards, Vol 02.06.
Annual Book of ASTM Standards, Vol 11.01.
5 7
Annual Book of ASTM Standards, Vol 15.03. Boldfacenumbersinparenthesesrefertothelistofreferencesattheendofthis
Annual Book of ASTM Standards, Vol 03.02. standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 1113
4.5 This test method is also applicable to situations produc-
ing continuous hydrogen permeation, such as high pressure
hydrogen cylinders or corrosion processes. The results, how-
ever, would require a different treatment and interpretation (4).
4.6 This test method is also applicable to small parts, such
as fasteners. The technique, procedure, and interpretation
would, however, have to be altered.
4.7 Use of this test method on austenitic stainless steels and
other face centered cubic (FCC) alloys would require different
measurement times and interpretation of results because of
differing kinetics.
4.8 Thistestmethodcanbeusedonslightlycurvedsurfaces
as long as the gasket defines a reproducible area. The area
calculation must, however, be changed.
5. Apparatus
5.1 Cell—Aphoto and drawing of a typical cell, which has
been found to be acceptable for hydrogen measurements, are
shown in Figs. 1 and 2, respectively.
5.1.1 Thecellismadeofanonmetallicmaterialthatwillnot
react with or contaminate the solution. The side opening has a
recess to accommodate the silicone rubber gasket.
5.1.2 Gasket, silicone rubber, shall provide a reproducible
FIG. 2 Engineering Drawing of Cell (3)
solution-contact area with the specimen, preferably 1.0 cm .
5.1.3 Cell Holder, a cradle-like C-clamp. Other clamping
devices can be used if necessary, such as for larger parts.
5.1.4 Cathode,anickel/nickeloxideelectrode.Itismadeby
removingthepositiveplatefromanickel/cadmiumbatteryand
attachinganickelwireorfoil.Theareaofthiscathodeshallbe
approximately five times that of the anode.
5.1.5 Anode—The anode is the specimen.
5.1.6 The cell is left open to the atmosphere. No purging is
used.
5.2 Current Measuring Device—The current can be mea-
sured by any method that will not affect its value. A zero
resistance ammeter (5), a current follower (6), and the current
measuring system shown in Fig. 3 (1) have been found to be
acceptable. The following description refers to Fig. 3.
5.2.1 Standard Resistor, connected across the cell through a
switch.
5.2.2 Electrometer, to determine the current by measuring
the voltage drop across the resistor. A 10-kV resistor with an
FIG. 1 Photograph of Cell FIG. 3 Schematic of Measuring Apparatus (1)
F 1113
electrometer having an input impedance of 10 V and a 1-mA 8.2 Determine the specimen contact area which is outlined
output has been found to be satisfactory. by the gasket.
5.2.3 Strip Chart Recorder, to monitor the electrometer 8.2.1 Assemble the cell with a smooth piece of aluminum
output. A recorder having an input resistance of 100 kV has sheet or foil, at least 0.04 mm thick, between a specimen and
been found to be satisfactory. the gasket. The Ni/NiO electrode is not needed.
5.2.4 Timer, accurate to within 10 s in a 30-min run. 8.2.2 Fill the cell with 0.2M NaOH solution and allow the
aluminum to be etched by the alkaline solution for about 20
6. Reagents
min.
8.2.3 Dismantle the cell and rinse well. A properly as-
6.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that sembled cell will produce a sharply defined, circular etch (see
Fig. 4).
all reagents shall conform to the specifications of the Commit-
tee onAnalytical Reagents of theAmerican Chemical Society, 8.2.4 Measure the diameter of the etched circle under a
microscope (103), and calculate the area (see 10.2).
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of 8.2.5 A poor gasket or improper tightening of the cell will
be detected by this procedure. Overtightening will produce a
sufficiently high purity to permit its use without lessening the
deformation of the gasket, resulting in an out-of-round etch.
accuracy of the determination.
Undertightening, or a worn-out gasket, will cause crevices,
6.2 Purity of Water—Distilled or deionized water conform-
resulting in etching under the gasket (see Fig. 4).
ing to Specification D1193, Type IV, shall be used to prepare
8.3 Measure uncoated coupons, prepared in accordance
all solutions.
with 7.1, to determine the background current density. Keep
6.3 Sodium Hydroxide Solution (0.2M)— Dissolve8gof
these coupons desiccated for at least one week before measur-
sodium hydroxide (NaOH) pellets in water and dilute to 1 L.
ing, to assure that no hydrogen, as a result of corrosion, is
6.4 Ammonium Nitrate Solution (120 g/L)—Dissolve 120 g
of ammonium nitrate (NH NO ) in water and dilute to 1 L. produced, and to allow any hydrogen in the specimens to
4 3
escape.
6.5 Methyl Alcohol (CH OH).
6.6 Ethyl Alcohol (C H OH).
2 5
NOTE 2—The background measurement is used only as a reference to
indicate the presence or absence of hydrogen. It is not used in any
7. Test Specimens
calculation.
7.1 The test specimen can be a coupon of 1- to 6-mm
9. Procedure
thickness or an actual part. If it is a coupon, it shall be of the
same alloy, form, temper/condition, and surface finish as the
NOTE 3—This procedure pertains to cadmium-plated specimens. Any
part. The specimen shall be of sufficient size to accommodate other plating must be removable by a method that will neither damage the
steel nor introduce hydrogen.
the cell and of sufficient smoothness and flatness to prevent
leakingoftheelectrolyteunderthegasket(see8.2).Ifpossible,
9.1 Specimen Preparation:
specimens shall be of sufficient size for a duplicate measure-
NOTE 4—The time to prepare the specimen must take no longer than 5
ment to be made (see 9.4).
min.
9.1.1 Remove any cadmium plate from an area on one side
8. Calibration and Standardization
of the specimen large enough to accommodate the cell (ap-
8.1 Calibrate the nickel/nickel oxide (Ni/NiO) electrode
proximately 40 by 40 mm) by swabbing with ammonium
against a saturated calomel electrode (SCE) in 0.2M NaOH.A
nitrate solution. Rinse with water and dry. Swabs made of
freshly charged Ni/NiO electrode will be at least 350 mV
polyurethane foam or cotton have been found to be satisfac-
positive to the SCE when measured according to Practice G3.
tory.
It shall be recharged when its potential is less than 300 mV
9.1.2 Abrade the surface lightly with an aluminum oxide-
positive to the SCE.
impregnated nylon cleaning pad to remove surface contamina-
NOTE 1—Repeated use of the Ni/NiO electrode will cause a temporary
tion and to provide a reproducible surface finish. Wipe clean
drain of the charge. To prevent this from happening, alternate two
using a tissue wet with methyl or ethyl alcohol.
electrodes during a series of measurem
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