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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What process variation would produce these different results? Ken Vlach – Goleta, California. We are getting poor coverage on the as-cast surface of some steel castings using a yellow Zinc chromate. Could you explain this? What type of zinc plating bath is your plater using?
ASTM B – 98 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel
High strength steels tensile strength greater than MPa shall not be electroplated. This applies to all metals. No, other colors may not be available if my presumption is right. The above entries are somewhat dated: Different brands of chromate conversion chemistry, possibly different plating processes acid zinc vs. Surfaces left-bare should be heavily chromated. Hello Claudio and Doug, My compliments for an excellent round of questions!
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. According to RoHS the homogeneous and non-homogeneous are defined in such manner that every one may understand that the layer is removable let’s see how.
Rest in peace, Ken. Corrosion Resistance Requirements Types. III is colorless and not expected to hold up as long as the colored II. Put the chromate on light.
The end user must decide when a part fails, at “white rust” corrosion the chromate has failed or asgm rust both the chromate and the zinc are gone exposing the base metal. Is this process done in the United States, and if so by asym The problem may not be with the chromate at all.
SC 4 very severe. As the USA moved toward metric fasteners, for a while there was a move to dye them blue. Try using an acid zinc chloride bath and see if the casting covers. August 31, A. The Standard default is gold for type II coatings unless otherwise specified.
ASTM B633-98 std: Electrodeposited coating of Zinc
I have the exact same questions. Did you ever get the answers you were looking for?
Regarding the question asked in letter ; Type II zinc plating vs. 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. 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. Surfaces to be painted should be ONLY lightly chromated. The part is currently being produced in China and my local platers are suggesting a dye to get a blue color.
Thank you for your hard work which the finishing world continues to benefit from. Does plating make that big a difference knowing that it’s going to be painted also? II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt spray. He passed away May 14, A Iron or steel with zinc electroplate.
Does anybody know this info? Obviously, this must be clarified by the customer.