ASTM B449-93 PDF
ASTM B() Standard Specification for Chromates on Aluminum Scope
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This abstract is a brief summary of the referenced standard. 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. I don’t believe coating wt. July 22, A. All information presented is for general reference and does not represent a professional opinion nor the policy of an author’s employer.
ASTM B449 – 93(2015)
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. Class 1; Class 2; Class 3; and Class 4. Class 1A- Clear For maximum protection against corrosion, painted or unpainted. 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, satm 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 qstm coatings are normally applied by dipping: The materials are classified according to its coating thickness: It might be worth getting your customers to waive or except the requirement in writing, assuming your coupons are passing the SS test. Not sure my question was to the point. Chromate conversion coatings are the most widely used coating for corrosion protection of Aluminum and Aluminum alloys minimizing surface oxidation.
Thank you for your help. 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.
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. Those specs are somewhat similar, but I do not think there is any claim that they are “technically equivalent”. No other units of measurement are included in this 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.
Class 3- Clear or Yellow For protection against corrosion where low electrical resistance is required. We test coating wt. Type II- Compositions containing no hexavalent chromium Class 1A- Clear For maximum protection against corrosion, painted or unpainted. 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.
Yes, a rough correspondence between what comprises class 2 vs. Thank you for your answer. From beautiful Pine Beach New Jersey: Joe Roter – Chatsworth, California, U. 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 qstm 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.
Class 3- Clear For protection against corrosion where low electrical resistance is required. Referenced Documents b449-39 separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Greg, it sure looks like it is available from ASTM at: We get a small commission for maintaining their links, so we can keep xstm perpetually current Asym can vouch that their pdf delivery works well at least on my computer, it did Historical Version s – view previous versions of standard.
July 21, Q. Your Metal Finishing Solution.
Chromate provides excellent corrosion resistance, is conductive and results in no measurable buildup 0. 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.
Chromate Conversion Coating
October 9, A. But even if you do, I’d suggest that you not certify compliance to a asmt you don’t have on hand. 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.
Class 1A- Yellow For maximum protection against corrosion, painted or unpainted.
ASTM B – 93() Standard Specification for Chromates on Aluminum
It is commonly used for an undercoat for paint or adhesive applications due to b4499-3 excellent bonding properties it provides. 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.
It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. It compares favorably with the hexavalent coatings providing a conversion coating that fulfills the corrosion, paint and electrical requirements of the different specifications. 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.
S October 11, A.