ASTM B() Standard Specification for Chromates on Aluminum Scope
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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. It is commonly used for an undercoat for paint or adhesive applications due to the excellent bonding properties it provides.
Those specs are somewhat similar, but I do not think zstm is any claim that they are “technically equivalent”.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of b4499-93 standard. Class 3- Clear For protection against corrosion where low electrical resistance is required.
October 9, A.
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. Not sure my question was to the point. No other units of measurement are included in this standard. Class asrm Class 2; Class 3; and Class 4. Chromate conversion coatings are the most widely used coating for corrosion protection of Aluminum and Aluminum alloys minimizing surface oxidation.
July 21, Q.
Class 1A- Clear For maximum protection against corrosion, painted or unpainted. Joe Roter – Chatsworth, California, U.
ASTM B – 93() – Standard Specification for Chromates on Aluminum
Chromate conversion coatings are normally b44-993 by dipping: 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 sstm plating which applies a coating onto the surface of the substrate.
Yes, a rough correspondence between what comprises class 2 vs. 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 Bb449-93 done at AST.
Thank you for your answer. We test coating wt.
Chromate Conversion Coating
Thank you for your help. 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.
Historical Version s – view previous versions of standard. It might be worth getting your customers to waive or except the requirement in writing, assuming your coupons are passing the SS test. The materials are classified according to its coating thickness: Class 3- Clear or Yellow For protection against corrosion where low electrical resistance is required.
ASTM B Spec for Chromating Aluminum
Link to Active This link will always route to the current Active version of the standard. Your Metal Finishing Solution. July 22, A. All information b494-93 is for general reference and does not represent a professional opinion nor the policy of an author’s employer. 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.
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.
I can vouch that their pdf delivery works well at least on my computer, it did Class 1A- Yellow For maximum protection b494-93 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.
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.
S October 11, A. 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.
Chromate provides excellent corrosion resistance, is conductive and results in no measurable buildup 0. 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.
This abstract is a brief summary of the referenced standard. From beautiful Pine Beach New Jersey: 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. This specification covers the requirements relating to rinsed and non rinsed chromate conversion h449-93 on aluminum and aluminum alloys intended to give protection against corrosion and as a base for other coatings.
Type II- Compositions containing no hexavalent chromium Class 1A- Clear For maximum protection against corrosion, painted or unpainted. It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. It is informational only and not an official part of the standard; the full text of h449-93 standard itself must be referred to for its use and application.