Zinc [ASTM-B] This specification covers requirements for electrodeposited zinc coatings applied to iron or steel articles. ASTM B ELECTRODEPOSITED COATINGS OF ZINC ON IRON AND STEEL. The coating is made according to demand, where the distribution is as follows. Blue/Zinc. Blue/Zinc. Yellow/Zinc. Yellow/Zinc. ASTM B Type II SC 3 (FE/ZN 13). Type II SC 2 (FE/ZN 8). Type II SC 1 (FE/ZN 5). Type III SC 3(FE/ZN 13).
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ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent. The end user must decide when a part fails, at “white rust” corrosion the chromate has failed or red rust both the chromate and the zinc are gone exposing the base metal.
What process variation would produce these different results? Zinc coating with colorless RoHS compliance passivation. It still will have Hex Chrome. Ray Kremer Stellar Solutions, Inc. Hi, I recently received 2 batches of parts from two b6633-85 platers using this specification.
Not the least of which is the environmental regulations impact on the future of the selected finish. II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt spray. As much as the last layer of the passivation is thin the electrical resistivity is low.
The type of passivation is determined according to the required characteristics, and is divided into groups:. Perhaps some confusion with Service Condition SC 2 moderatewhich indicates a minimum zinc thickness of 8 microns and is commonly clear chromated Type III.
Rest in peace, Ken. Obviously, this must be clarified by the customer. Sorry, but if you need one particular look, you must go through the ugly process of maintaining sample boards with acceptable vs. Yellow chromate should get 96 hrs to failure. No, other colors may not be available if my presumption is right.
Regarding the question asked in letter ; Type II zinc atsm vs. I’ve seen this done less commonly on chromated zinc plating than asgm chromated aluminum.
The rust not only harms the aesthetically smooth look, but also its mechanic needs. Going with clear will make it difficult to tell what is clear chromated zinc vs.
High strength steels tensile strength greater than MPa shall not be electroplated. They share, however, the most basic of metal finishing requirements: I am not getting the difference between this. Our plater would like to go to a clear zinc, but our customer is under the assumption that the clear will not do as good a job with corrosion resistance and salt spray life. Zinc plated components vary from one industry to another. Put the chromate on light.
The Zinc coating provides a smooth look as well as good anti-corrosive protection. Zinc coating with phosphate passivation. Surfaces left-bare should be heavily chromated.
ASTM B – 85e1 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel
This applies to all metals. Type II b63-85 are more commonly used where greater corrosion resistance is required, e.
That seems a bit discretional to me. Until a very few years ago chromate conversion coatings were based on hexavalent chromium, and deposited a thick film that was relatively easy to dye.
Olive Drab chromate is hrs.
ASTM B datasheet & applicatoin notes – Datasheet Archive
Colorless RoHS compliance passivation gives corrosion resistance ability of 72 hours according to ASTM B until white spots-also intended to parts used in a high corrosive environment —outdoor. The type of passivation is determined according to the required characteristics, and is b6333-85 into groups: Does anybody know this info? Corrosion Resistance Requirements Types.
Is there any colour difference OR is there any Salt spray difference? What type of zinc plating bath is your plater using? Zinc and Zinc alloys, such as zinc-nickel will surely play a more significant role as metals such as Cadmium are destined for the elements’ Valhalla. August 31, A.
III zinc plating A discussion started in but continuing through Q. Electrical charasteristics As b63-385 as the last layer of the passivation is thin the electrical resistivity is low.