ASTM Standards: B Practice for Operating Salt Spray (Fog) Apparatus2. B Guide for Engineering Chromium Electroplating3. B Practice for. Endorsed by AmericanDesignation: B – 01 (Reapproved )e1. ASTM B/BM() Standard Guide for Engineering Chromium Electroplating Scope
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If a nondestructive method is required, magnetic induction methods in accordance with Test Method B are suitable for chromium over magnetic substrates.
Face shield, chemical goggles, rubber gloves, and other safety equipment should be used when handling sulfuric acid and when making this addition. B on areas that should be electroplated. A reversing switch should be provided to make the part anodic. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.
X-Ray uorescence may be used to measure very thin chromium deposits of 1 to 20 m 3 in. Need more than one copy?
ASTM B177/B177M – 11(2017)
This guide provides information on the deposition of engineering chromium asgm electroplating. The preceding solution should, of course, zstm handled with all the astk required of standard chromium plating baths. Chemical lead is also satisfactory where hardness and rigidity are not important.
The design of racks for chromium electroplating on the various base metals previously mentioned for functional use should provide for the following to the greatest possible extent. These co-catalysts may use organic based or inorganic based compounds to achieve higher plating efficiencies and are often employed where higher rates of plating and better throwing and covering power are needed. Deoxidizing and Etching 6.
NOTE 1—Many factors inuence the choice of current densities. Analytical control of the silicouoride is more difficult than the other components, but ion selective methods are satisfactory.
Link to Active This link will always route to the current Active version of the standard. This should be done after any stressrelieving heat treatment. There are also proprietary solutions available which should be operated according to the supplier’s instructions.
Practice B offers many ways to prepare titanium prior to chromium electroplating. Most proprietary chromium plating baths are co-catalyzed plating solutions in which an additional catalyst is used b1777 conjunction with the traditional sulfate anion catalyst. Repair of Chromium Electrodeposits on Steel Substrates 9. Due to the high carbon content in iron castings, anodic etching leaves a carbon smut on the surface of the metal which results in poor adhesion of the chromium.
Mild steel anodes are usually b1777. Leadsheathed steel, copper, or silver may be used when indicated by requirements for strength or conductivity. Consult with appropriate safety astj or safety personnel, or both, before handling sulfuric acid or chromic acid!
When direct measurement of the thickness of the coating is desired 1b77 the part can be sacriced, it should be done in accordance asym Test Method B Some stainless steels benet from a Woods nickel strike prior to chromium electroplating. If the anode contains little or no lead, the reoxidation of trivalent chromium to the hexavalent state will not take place or will be seriously impaired, which will lead to trivalent buildup in the plating solution and poor results.
The procedure and requirements for the following are detailed: Materials such as aluminum and titanium have an inherent oxide lm on the surface that can only be removed or minimized just prior to the electroplating process see 6.
ASTM B/BM – 11() – Standard Guide for Engineering Chromium Electroplating
Tank voltage is normally 4 to 5 V. This standard is also available to be included in Standards Subscriptions.
With very great agitation, the highest current density shown is possible with a concomitant decrease in the plating time. There are many modications reported in the literature and some manufacturers offer proprietary baths. 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. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
In operating these baths, it is essential that no sulfate be introduced into the bath. B1777 published as B — Chromium deposited from the higher concentration sulfate catalyzed baths are less prone to macrocracking during grinding than those deposited under similar conditions from a cocatalyzed bath see 7.
Standard Guide for Engineering Chromium Electroplating
This acid also requires great care in handling. Any auxiliary anodes integrated with the rack are connected to the anode bus bar. In general, anodic etching in the chromium plating solution is not recommended. This stress relief is essential if hydrogen embrittlement from subsequent operations is to be avoided.
The deposits are dull gray in color and can be buffed, if desired.
Specified chromium electrodeposits on ferrous surfaces are defined in Specification B It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application.
This standard is subject to revision at any time by the responsible technical committee and must asym reviewed every ve years and if not revised, either reapproved or withdrawn.