ASTM F326-96(2012)

Standard Test Method for Electronic Measurement for Hydrogen Embrittlement From Cadmium-Electroplating Processes

SIGNIFICANCE AND USE
5.1 Hydrogen is evolved during metal electrodeposition in aqueous baths. Some of this hydrogen enters parts during plating. If the absorbed hydrogen is at a level presenting embrittlement hazards to high-strength steel, it is removed by baking parts after plating to expel this hydrogen. However, the lack of plate porosity itself may block hydrogen egress. Thus, it becomes important to know both the relative amount of hydrogen absorbed and the plate porosity.  
5.2 This test provides a quantitative control number for cadmium plate porosity that can be used to control a cadmium plating process and the status of cadmium-plated hardware. It can also be used for plating process troubleshooting and research and development to determine the effects on plate porosity by process variables, contaminants, and materials. When used to control a critical process, control numbers for plate porosity must be determined by correlation with stress rupture specimens or other acceptable standards.  
5.3 There is no prime standard for plate porosity. For this reason, two ovens must be used, with tests alternated between ovens. Data from the ovens are compared to ensure no equipment change has occurred.
SCOPE
1.1 This test method covers an electronic hydrogen detection instrument procedure for measurement of plating permeability to hydrogen. This method measures a variable related to hydrogen absorbed by steel during plating and to the hydrogen permeability of the plate during post plate baking. A specific application of this method is controlling cadmium-plating processes in which the plate porosity relative to hydrogen is critical, such as cadmium on high-strength steel.  
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statement, see Section 8.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

General Information

• Status: Historical
• Publication Date: 31-Oct-2012
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: F07 - Aerospace and Aircraft
• Drafting Committee: F07.04 - Hydrogen Embrittlement

Relations

• Replaces: ASTM F326-96(2006) - Standard Test Method for Electronic Measurement for Hydrogen Embrittlement From Cadmium-Electroplating Processes
• Effective Date: 01-Nov-2012

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:F326 −96 (Reapproved 2012)
Standard Test Method for
Electronic Measurement for Hydrogen Embrittlement From
1
Cadmium-Electroplating Processes
ThisstandardisissuedunderthefixeddesignationF326;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Symbols:
3.2.1 HP =calibration hydrogen pressure peak.
1.1 This test method covers an electronic hydrogen detec-
3.2.2 HP =plating hydrogen pressure peak.
tion instrument procedure for measurement of plating perme-
p
abilitytohydrogen.Thismethodmeasuresavariablerelatedto
3.2.3 I =probe cathode emission current.
E
hydrogen absorbed by steel during plating and to the hydrogen
3.2.4 I =probe hydrogen pressure.
H
permeability of the plate during post plate baking. A specific
3.2.5 I =integral of I curve from probe on to HP.
γ H
application of this method is controlling cadmium-plating
3.2.6 lambda =time in seconds for hydrogen pressure peak
processes in which the plate porosity relative to hydrogen is
to drop to half its value.
critical, such as cadmium on high-strength steel.
3.2.7 λ=lambda obtained from a calibration run.
1.2 This standard does not purport to address all of the
3.2.8 λ =lambda obtained from a plating run.
p
safety concerns, if any, associated with its use. It is the
3.2.9 λ =normalized test lambda, obtained as follows:
pc
responsibility of the user of this standard to establish appro-
λ 5λ 40/λ (1)
~ !
priate safety and health practices and determine the applica- pc p
bility of regulatory limitations prior to use. For specific hazard
¯
3.2.10 λ =arithmeticaverageofnormalizedlambdasfora
pc
statement, see Section 8.
set of tests.
1.3 The values stated in SI units are to be regarded as the
3.2.11 range =difference between maximum λ and mini-
pc
standard. The values given in parentheses are for information
mum λ for a given set of tests.
pc
only.
3.2.12 run =calibration or plating of a probe.
2. Referenced Documents
3.2.13 test =single evaluation of a plating solution for
2
hydrogen embrittlement determination; run using a previously
2.1 ASTM Standards:
calibrated probe.
D1193Specification for Reagent Water
3.2.14 set of tests—all consecutive tests on a plating solu-
F519Test Method for Mechanical Hydrogen Embrittlement
tion for a given operator-instrument-day evaluation.
Evaluation of Plating/Coating Processes and Service En-
vironments
3.2.15 window—test surface of a probe described in Fig.
1(A).
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
4. Summary of Test Method
3.1.1 hydrogen pressure peak—the maximum hydrogen
4.1 This method uses a metal-shelled vacuum probe as an
pressure value (see I ) obtained when the probe is heated
H
ion gage to evaluate electrodeposited cadmium characteristics
following calibration, plating, or fluid testing.
relative to hydrogen permeation.After calibration, a section of
the probe shell is electroplated at the lowest current density
encounteredinthecadmiumelectroplatingprocess.Duringthe
subsequent baking of the probe at a closely controlled
1
This test method is under the jurisdiction of ASTM Committee F07 on
temperature, the probe ion current, proportional to hydrogen
Aerospace andAircraft and is the direct responsibility of Subcommitteee F07.04 on
Hydrogen Embrittlement. pressure,isrecordedasafunctionoftime.Fromthesedataand
Current edition approved Nov. 1, 2012. Published November 2012. Originally
the calibration data of the probe, a number related to the
approved in 1978. Last previous edition approved in 2006 as F326–96(2006).
porosity of the electroplated metal relative to hydrogen is
DOI: 10.1520/F0326-96R12.
2
obtained.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4.2 During the initial part of the bakeout, hydrogen contin-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ues to diffuse through the metal shell of the probe and the ion
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F326−96 (2012)
FIG. 1 Probe Configuration
current increases. Within a short time, however, a maximum 6.2 Oven—The oven warms the probe to increase the
current is observed and then falls off as hydrogen is driven out hydrogen diffusion rate into the probe. Oven parameters are
of the system. selected by apparatus manufacturer to provide a standard
reading for all hydrogen detection instruments.
4.3 Observations of the ion current-time curve indicate that
thes
...