ASTM B343-92a(2020)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B343 − 92a (Reapproved 2020) Endorsed by American
Electroplaters’ Society
Endorsed by National
Association of Metal Finishers
Standard Practice for
Preparation of Nickel for Electroplating with Nickel
This standard is issued under the fixed designation B343; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Types of Nickel
1.1 This practice summarizes well-known, generally practi- 2.1 Thetypesofnickelforwhichanoverplateofnickelmay
cal methods for producing adherent electrodeposits of nickel be desired are dull nickel, semi-bright nickel, bright nickel, and
on nickel. nickel strike. Variations in these types may possibly require
special handling.
1.2 Electrodeposits of nickel on nickel are produced, for
example,toimprovetheperformanceofdecorativecoatings,to 2.2 Surface conditions of the nickel may vary as follows:
reclaim electroplated parts that are defective, and to resume 2.2.1 Freshly electroplated surfaces that are still wet with
nickel electroplating after interruptions in processing. Interrup- electroplating solution or rinse water (see 5.1),
tions may be deliberate, for example, to machine the electrode- 2.2.2 Freshly electroplated surfaces that have been allowed
posit at an intermediate stage in the electrodeposition of thick to dry (see 5.2),
nickel coatings. The interruptions may be unintentional, for 2.2.3 Buffed, polished, or machine-ground surfaces (see
example, resulting from equipment and power failures. 5.3), and
2.2.4 Surfaces that have been given a reverse-current treat-
1.3 To ensure good adhesion of nickel to nickel, precautions
ment in an alkaline solution for cleaning or possibly stripping
should be taken to avoid biopolar effects during nickel elec-
an overplate of chromium (see 5.4).
troplating. This is of particular importance in return-type
automatic plating machines where one rack follows another
3. Cleaning
rack closely. Bipolar effects can be avoided by making the
racks cathodic while they are entering or leaving the nickel 3.1 The following cleaning treatments may be used for all
conditions and types of electrodeposited nickel. The choice of
tank. Separate current control on entry and exit stations is
desirable. the procedure will be governed largely by the condition of the
surface.
1.4 The values stated in SI units are to be regarded as
3.1.1 Degreasing—Degreasing is used to remove the bulk
standard. No other units of measurement are included in this
of grease, oil, and buffing compounds that may be present on
standard.
the surface. The cleaning may be effected with vapor
1.5 This standard does not purport to address all of the
degreasing, organic solvents, emulsion cleaners, or soak
safety concerns, if any, associated with its use. It is the
cleaner.
responsibility of the user of this standard to establish appro-
3.1.2 Electrolytic Alkaline Cleaning—Removal of final
priate safety, health, and environmental practices and deter-
traces of dirt, grease, and oil is accomplished best with
mine the applicability of regulatory limitations prior to use.
electrolytic alkaline cleaning. The solution may be either a
1.6 This international standard was developed in accor-
proprietary cleaner or a formulated one. Since a nickel surface
dance with internationally recognized principles on standard-
forms an oxide coating if treated anodically in an alkaline
ization established in the Decision on Principles for the
solution, this condition must be altered in subsequent steps if it
Development of International Standards, Guides and Recom-
cannot be avoided.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Activating
4.1 The procedure used for etching or activating the nickel
surface usually determines the soundness of the adhesion. The
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.02 on
choice of the procedure may be governed by the condition of
Pre Treatment.
the surface and possibly the type of nickel. The milder etching
Current edition approved Nov. 1, 2020. Published December 2020. Originally
treatment should be used in the case of highly finished
approved in 1960. Last previous edition approved in 2014 as B343 – 92a(2014).
DOI: 10.1520/B0343-92R20. surfaces, but it may result in sacrificing maximum adhesion.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B343 − 92a (2020)
The thickness of the nickel may militate against the use of 4.6 Etching by Acid Immersion—(Nickel removed approxi-
certain etching procedures, and therefore the thickness re- mately 1.3 µm.) Adequate etching may be obtained on some
nickel surfaces by a short dip at room temperature in a solution
moved is indicated for each procedure described in 4.2 to 4.8.
of either 500 mL of concentrated 37 mass % hydrochloric acid
4.2 Anodic Treatment in Concentrated Sulfuric Acid—
(density 1.18 g/mL) diluted to 1 L, or 150 mL of concentrated
(Nickel removed nil). A70 mass % sulfuric acid solution
96 mass % sulfuric acid (density 1.83 g/mL) diluted to 1 L. See
containing 661 mL of concentrated, 96 mass % sulfuric acid
4.2. The length of the immersion required may vary from 10 s
(density 1.83 mL) diluted to 1 Lmay be used for activating the
to 1 min.
nickel surface provided the temperature of the solution is not
4.7 Electropolishing Treatment—(Nickel removed approxi-
over 30 °C (see Warning). When the initial mixture cools,
mately 1.3 µm.) This procedure is commonly employed on
dilute to exact volume. The time of treatment should be about
rejects that have been repolished to remove the defective area.
1 min at a current density of 10 A/dm . At this current density
The electropolishing solution commonly used consists of a
the nickel normally goes passive and a bright surface becomes
mixture of 150 mL of 96 mass % sulfuric acid (density
only slightly dull. This type of passivity is removed by
1.83 g⁄mL) and 630 mLof 85 mass % phosphoric acid (density
subsequent rinsing in water. (Warning—Slowly add the sul-
1.69 g⁄mL) diluted to 1 L. See Warning in 4.2.Temperature of
furic acid with rapid stirring to the approximate amount of
solution ranges from 45 to 55 °C. The work is made anodic at
water required.)
current densities from 15 to 20 A/dm . The electropolishing
4.3 Anodic Etching in Sulfuric Acid—(Nickel removed
treatment is usually applied for 2 to 15 min. The cathodes may
approximately 1.3 µm.) A25 mass % sulfuric acid solution,
be electrolytic nickel strip. Subsequent alkaline cleaning and
containing 166 mL
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