ASTM B630-88(2010)
(Practice)Standard Practice for Preparation of Chromium for Electroplating with Chromium
Standard Practice for Preparation of Chromium for Electroplating with Chromium
SIGNIFICANCE AND USE
Electrodeposits of chromium on chromium are produced in cases where it is desired to obtain a better performing coating, to reclaim plated parts that are defective, or restore worn chromium coatings to original dimensions.
SCOPE
1.1 This practice is intended to serve as a process guide (not as a standard procedure) for producing adherent electrodeposits of chromium on chromium for engineering use.
1.2 Only well-known, generally practical methods using hexavalent chromium plating baths have been included. Some of the newer proprietary chromium plating processes produce chromium plating for which this process is unsuitable. Suppliers of the processes should be consulted.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: B630 − 88 (Reapproved 2010)
Standard Practice for
Preparation of Chromium for Electroplating with Chromium
This standard is issued under the fixed designation B630; 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 4.2 Stripping and Basis Metal—With previously electro-
plated parts where the chromium deposit has been worn
1.1 This practice is intended to serve as a process guide (not
through, or where grinding has exposed the basis metal,
asastandardprocedure)forproducingadherentelectrodeposits
preferred results are obtained by stripping the remaining
of chromium on chromium for engineering use.
chromium completely. However, it is possible to obtain satis-
1.2 Only well-known, generally practical methods using
factory deposits on such substrates by careful attention to
hexavalent chromium plating baths have been included. Some
details in the pretreatment and electroplating process steps.
of the newer proprietary chromium plating processes produce
4.3 Stripping may be done by several methods, including
chromium plating for which this process is unsuitable. Suppli-
proprietary processes or inhibited hydrochloric acid solution
ers of the processes should be consulted.
(10 to 20 % by volume), or anodic treatment at 55 to 800A/m
1.3 The values stated in SI units are to be regarded as 2
(5 to 75 A/ft ) in a solution of 35 to 50 g/L (5 to 7 oz/gal) of
standard. No other units of measurement are included in this
sodium hydroxide or 60 to 75 g/L (8 to 10 oz/gal) of sodium
standard.
carbonate at 20 to 25°C (70 to 80°F).
1.4 This standard does not purport to address all of the
4.4 Process Outline:
safety concerns, if any, associated with its use. It is the
4.4.1 Preclean (see 5.1.1 and 5.1.2),
responsibility of the user of this standard to establish appro-
4.4.2 Alkaline electrolytic clean (see 5.1.3),
priate safety and health practices and determine the applica-
4.4.3 Rinse (cold water),
bility of regulatory limitations prior to use.
4.4.3.1 Rinse (hot water),
2. Referenced Documents
4.4.3.2 Dry,
4.4.3.3 Mask (see 5.2),
2.1 ASTM Standards:
4.4.4 Activate (see 5.3),
B177 Guide for Engineering Chromium Electroplating
4.4.5 Chromium electroplate,
3. Significance and Use
4.4.6 Rinse (cold water),
3.1 Electrodepositsofchromiumonchromiumareproduced
4.4.7 Rinse (hot water), and
in cases where it is desired to obtain a better performing
4.4.8 Dry.
coating, to reclaim plated parts that are defective, or restore
worn chromium coatings to original dimensions.
5. Procedure
5.1 Cleaning—The following cleaning treatments may be
4. Preparation of Surface
used for all conditions and types of electrodeposited chro-
4.1 Surface Finishing—The smoothness of the chromium
mium. The choice of the procedures will be governed largely
coating before electroplating with chromium should closely
by the condition of the surface.
approximate the requirements of the finished part. It is usually
5.1.1 Precleaning—When considerable amounts of grease
achieved by appropriate grinding with a diamond wheel.
and oil are present on the surface, precleaning (emulsion or
alkaline spray or soak) is necessary to remove the bulk of the
This practice is under the jurisdiction of ASTM Committee B08 on Metallic soil.
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.02 on
5.1.2 Abrasive Cleaning—Oxide and other films may be
Pre Treatment.
removedbymechanicaltechniquesusingsuchabrasivesasfine
Current edition approved Nov. 1, 2010. Published November 2010. Originally
emery on a cloth or a wheel, pumice slurry, or greaseless
approved in 1977. Last previous edition approved in 2006 as B630 – 88 (2006).
DOI: 10.1520/B0630-88R10.
buffing compounds. Grit blasting, shot blasting, wet blasting,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
or vapor honing may also be used. Abrasive cleaning is
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
generally not necessary when suitable mechanical finishing
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. procedures have been used.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.