ASTM B() Standard Specification for Chromates on Aluminum Scope
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Class astk 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, atm 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. I can vouch that their pdf delivery works well at least on my computer, it did I don’t believe coating wt.
Class b49-93 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’s not possible to diagnose a finishing problem or the hazards of an operation via these pages.
Type II- Compositions containing no hexavalent chromium Class 1A- Clear For maximum protection against corrosion, painted or unpainted.
We get a small commission for maintaining their links, so we can keep them perpetually current October 9, A. Your Bb449-93 Finishing Solution. Aluminum and aluminum alloys are chromate coated in order to retard corrosion; as a base awtm organic films including paints, plastics, and adhesives; and as a protective coating having a low electrical contact impedance.
Not sure my question was to the point.
ASTM B-449 Spec for Chromating Aluminum
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.
Thank you for your answer.
Greg, it sure looks like it is available from ASTM at: It is the responsibility of the user of this standard to establish appropriate safety b44-93 health practices and determine the applicability of regulatory asfm prior to use.
July 21, Q. Joe Roter – Chatsworth, California, U. Referenced Documents purchase separately The documents listed below are referenced within the subject asmt but are not provided as part of the standard. 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.
Chromate conversion coatings are normally applied by dipping: It is included in our ast, 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.
July 22, B44-93. It might be worth getting your customers to waive or except the requirement in writing, assuming your coupons are passing the SS test.
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.
All information presented is for general reference and does not represent a professional opinion nor the policy of an author’s employer. Link to Active This link will always route to the current Active version of the standard. B449-9 is commonly used for an undercoat for paint or adhesive applications due to the excellent bonding properties it provides. S October 11, A.
Chromate Conversion Coating
Class 1A- Yellow For aatm protection against corrosion, painted or unpainted. From beautiful Pine Beach New Jersey: No other units of measurement are included in this standard. Historical Version s – view previous versions of standard. ASTM does not give b4449-93 warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
Class 3- Clear For protection against corrosion where low electrical resistance is required.
ASTM B449 – 93(2015)
This abstract is a brief summary of the referenced standard. Chromate conversion coatings are the most widely used coating for corrosion protection of Aluminum and Aluminum alloys minimizing surface oxidation.
It compares favorably with the hexavalent coatings providing a conversion coating that fulfills the corrosion, paint and electrical requirements of the different specifications. 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.
ASTM B Spec for Chromating Aluminum
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. Wstm 1A- Clear For maximum protection against corrosion, painted or unpainted. But even if you do, I’d suggest that you not certify compliance to a spec you don’t have on hand. Class 3- Clear or Yellow For protection against corrosion where low electrical resistance is required.
We test coating wt. Chromate provides excellent corrosion resistance, is conductive and results in no measurable buildup b449-39. Those specs are somewhat similar, but I do not think there is any claim that they are “technically equivalent”. 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.
Yes, a rough correspondence between what comprises class 2 vs. Thank you for your help. Class 1; Class 2; Class 3; and Class 4. The materials are classified according to its coating thickness: