ASTM B Type II and III zinc chromate plating Q&A’s. *Note: Answer is based upon pre versions of B (, , ). The revision. Hi, can anyone advise if the ASTM std ASTM B [link by ed. to spec at TechStreet] std specification for Electroplated coatings on Iron and steel, the . ASTM Be1 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel Scope This specification covers requirements .
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The b633-988 may not be with the chromate at all. The above entries are somewhat dated: To determine the nature of accuracy or revision level please verify above data with current releases: Numeral indicates thickness in micrometers.
Zinc Plating: ASTM B Type II vs. III
Mark Hollenbeck alloys – Muskegon, Michigan A. So if you need to color match, you need to do it with a requirement for compliance with sample parts — not a verbal asttm. It still will have Hex Chrome. II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt spray.
In 24 years I have only been asked this question once before and I presume it involves phosphating over zinc plating for those heavy phosphating grammage applications, where normal phosphating will not provide enough zinc phosphate that is required in the deposit.
I need to specify platings that do not contain Hexavalent Chromium for parts that will be used in the automotive industry. The part is currently being produced awtm China and my local platers are suggesting a dye to get a blue color.
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.
ASTM B633-98 std: Electrodeposited coating of Zinc
So if I’m interpreting this correct, there is both a color difference and a salt spray difference. 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.
Surfaces to be painted should be ONLY lightly chromated. I am not getting the difference between this.
ASTM B-633 Type II vs. III zinc plating
The answer is Yes. A Blue with pale yellow is the best replacement for yellow as of now. Corrosion Resistance Requirements Types. Sorry, but if you need one particular look, you must go through the ugly process of maintaining sample boards with acceptable vs.
Trivalent chromates give paler and lighter finishes; some use metals, some use atm, some use dyes, in order to replicate the Hex finish.
ASTM B std: Electrodeposited coating of Zinc
August 31, A. 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.
A heavy chromate will shear under paint and cause the paint to peel. Can anyone give me some direction on how to get the customer to accept going to clear. As the USA moved toward metric fasteners, b33-98 a while there was a move to dye them blue.
Rest in peace, Ken. All I asym to know is what color the types are. Obviously, this must be clarified by the customer. Some of today’s proprietary trivalent chromium coatings are very thin and consequently will zstm generate a highly saturated color though.
Don Penzenik – Elkhart, Indiana. Hi, I recently received 2 batches of parts from two separate platers using this specification. It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. From beautiful Pine Beach New Jersey: I have the exact same questions.