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 .
|Published (Last):||5 April 2013|
|PDF File Size:||5.43 Mb|
|ePub File Size:||14.94 Mb|
|Price:||Free* [*Free Regsitration Required]|
A Blue with pale yellow is the best replacement for yellow as of now. The revision addresses RoHS concerns and specifically allows non-hexavalent chromate treatments.
Type II chromates are more commonly used where greater corrosion resistance is required, e. He passed away May 14, It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages.
I’ve seen this done less commonly on chromated zinc plating than on chromated aluminum. Could you explain this? 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.
So if I’m interpreting this correct, there is both a color difference and a salt spray difference. The Standard default is gold for type II coatings unless otherwise specified.
Different brands of chromate conversion chemistry, possibly different plating processes acid zinc vs. Surfaces to be painted should be ONLY lightly chromated. Numeral indicates thickness in micrometers.
Some of today’s proprietary trivalent chromium coatings are very thin and consequently will not generate a highly saturated color though.
ASTM B-633 Type II vs. III zinc plating
All I need to know is what color the types are. But if you are looking for something indisputably blue, as opposed to clear with a possible slightly bluish cast, this probably requires dye. 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. As the USA moved toward metric fasteners, for a while there was a move to dye them blue. According to RoHS the homogeneous and non-homogeneous are defined in such manner that b633–98 one may understand that the layer is removable let’s see how.
Hi, I recently received 2 batches of parts from two separate platers using this specification. Ray Kremer Stellar Solutions, Inc.
ASTM B – 98 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel
Rest in peace, Ken. From beautiful Pine Beach New Jersey: It still will have Hex Chrome. The part is currently being produced in China and my local platers are suggesting a dye to get a blue color. 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 ashm gone exposing the base metal. What process variation would produce these different results? Certain castings are difficult, if not impossible, to plate in either cyanide or alkaline non-cyanide plating baths.
Perhaps atm confusion with Service Condition SC 2 moderatewhich indicates a minimum zinc thickness of 8 microns and is commonly clear chromated Type III. Ken Vlach – Goleta, California. Try using an acid zinc chloride bath and see if the casting covers.
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. A Iron or steel with zinc electroplate. B63398 if you need to color match, you need to do it with a requirement for compliance with sample parts — not a verbal description. Trivalent chromates give paler and lighter finishes; some use metals, some use permanganates, some use dyes, in order to replicate the Hex finish. No it awtm not imply that.
III zinc plating A discussion started in but continuing through Q. Not the least of which is the environmental regulations impact on the future of the selected finish. Regards, Ted Mooney, P.
ASTM B633-98 std: Electrodeposited coating of Zinc
II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt spray. The problem may not be with the chromate at all. Regarding the question asked in letter ; Type II zinc plating vs. The above entries are somewhat dated: I need to specify platings that do not contain Hexavalent Chromium for parts that will be used in the automotive industry.