ASTM B() Standard Specification for Chromates on Aluminum Scope
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We get a small commission for maintaining their links, so we can keep them perpetually current Chromate Conversion Coating also commonly referred to as Chemical Film, Chem Film, Alodine or Iridite converts the surface properties of the substrate typically aluminum or magnesium as compared to plating which applies a coating onto the surface of the substrate. October 9, A. I can vouch that their pdf delivery works well at least on my computer, it did Yes, a rough correspondence between what comprises class 2 vs.
Link to Active This link will always route to the current Active version of the standard. Class 1; Class 2; Class 3; and Class 4. Historical Version s – view previous versions of standard.
Chromate Conversion Coating
Class 1A- Yellow For maximum b449-3 against corrosion, painted or unpainted. From beautiful Pine Beach New Jersey: 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.
Aluminum and aluminum alloys are chromate coated in order to retard corrosion; as a base for organic films including paints, plastics, and adhesives; and as a protective coating having a low electrical contact impedance. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
Those specs are somewhat similar, but I do not think there is any claim ashm they are “technically equivalent”. Both Hexavalent and Trivalent films at Advanced Surface Technologies have passed initial hour salt spray testing and are subject to monthly hour salt spray testing as well as paint adhesion testing conforming to all specifications.
July 22, A. Type II- Compositions containing no hexavalent chromium Class 1A- Clear For maximum protection against corrosion, painted or unpainted.
S October 11, A. It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. I don’t believe coating wt. We test coating wt.
Class 1- Yellow to Brown, Maximum corrosion resistance generally used as final finish Class 2- Colorless to yellow, Moderate corrosion resistance, used as a paint base and for bonding to rubber Class 3- Colorless, Decorative, slight corrosion resistance, low electrical contact resistance Class 4- light green to green, Moderate corrosion resistance, used as a paint base and for bonding to rubber Not done at AST. Thank you for your help. The materials are classified according to its coating thickness: Thank you for your answer.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. It might be worth getting your customers to waive or except the requirement in writing, assuming your coupons are passing the SS test. Advanced Surface Technologies extensive experience with the chromate process enables us to effectively process cast and all the different wrought alloys with alloy specific pre-treatment chemistries.
Class 1A coatings give maximum corrosion protection with the highest electrical surface resistance while class 3 coatings have lower corrosion protection and provide lower electrical surface resistance. It is commonly used for an undercoat for paint or adhesive applications due to the excellent bonding properties it provides.
This specification covers the requirements relating to rinsed and non rinsed chromate conversion coatings on aluminum and aluminum alloys intended to give protection against corrosion and as a base for other coatings. Your Metal Finishing Solution.
Class 3- Clear or Yellow For protection against corrosion where low electrical resistance 4b49-93 required. July 21, Q. All information presented b4499-93 for general reference and does not represent a professional opinion nor the policy of an author’s employer. This abstract is a brief summary of the referenced standard. No other units of measurement are included in this standard. Chromate conversion coatings are normally applied by dipping: Not sure my question was to the point.
Greg, it sure looks like it is available from ASTM at: It compares favorably with the hexavalent coatings providing a conversion coating that fulfills the corrosion, paint and electrical requirements of the different specifications. Chromate provides excellent corrosion resistance, is conductive and results in no measurable buildup 0.
ASTM B449 – 93(2015)
Class 1A- Clear For maximum protection against corrosion, painted or unpainted. It is included in our internal testing matrix, but none of our customers require it and I can not find it in MIL-C, so I would like to remove it from monthly testing.
Joe Roter – Chatsworth, California, U. Chromate Classes Class 1- Yellow to Brown, Maximum corrosion resistance generally used as final finish Class 2- Colorless to yellow, Moderate corrosion resistance, used as a paint base and for bonding to rubber Class 3- Colorless, Decorative, slight corrosion resistance, low electrical contact resistance Class 4- light green to green, Moderate corrosion resistance, used as a paint base and for bonding to rubber Not done at AST.
Chromate conversion coatings are the most widely used coating for corrosion protection of Aluminum and Aluminum alloys minimizing surface oxidation.
ASTM B Spec for Chromating Aluminum
Class 3- Clear For protection against corrosion where low electrical resistance is required. But even if you do, I’d suggest that you not certify compliance to a spec you don’t have on hand. 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.