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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Obviously, this must be clarified by the customer. Ken Vlach – Goleta, California.
ASTM B – 98 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel
Certain castings are difficult, if not impossible, to plate in either cyanide or alkaline non-cyanide plating baths. You can get the same finish only for blue and black hex chrome with tri substitutes, but not for yellow or olive as of yet.
The designer and engineer must take into account several considerations to stay at the forefront of the finish potential. He passed away May 14, 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.
III is colorless and not expected to hold up as long as the colored II. The part is currently being produced in China and my local platers are suggesting a dye to get a blue color. It’s not possible to diagnose a axtm problem or the hazards of an operation via these pages. Hello Claudio and Doug, My compliments for an excellent b63-98 of questions! What do you say? Type II chromates are more commonly used where greater corrosion resistance is required, e.
I am not getting the difference between this. Try using an acid zinc chloride bath and see if the casting covers. This applies to all metals. Olive Drab chromate is hrs. Numeral indicates thickness in micrometers.
I have the exact same questions. It still will have Hex Chrome. So if you need to color match, you need to do it with a requirement xstm compliance with sample parts — not a verbal description.
That seems a bit discretional to me. Yellow chromate should get 96 hrs to failure. I will be attending the ASTM B8 committee meetings in Philly later this week and will mention this letter to the sub-committee chair responsible for the B ast. No it does not imply that. The problem may not be with the chromate at all. 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’m not a zinc plater, but ‘Type II Clear’ seems self-contradictory. The Standard default is gold for type II coatings unless otherwise specified. Also, some yellow chromates are clear w.
ASTM B633-98 std: Electrodeposited coating of Zinc
Answer is based upon pre versions of B, Rest in peace, Ken. It does not cover zinc-coated wire or sheets. Is there any wstm difference OR is there any Salt spray difference? SC 4 very severe.
ASTM B-633 Type II vs. III zinc plating
What process variation would produce these different results? Mark B633-9 alloys – Muskegon, Michigan A. But if you are looking for something indisputably blue, as opposed to clear with a possible slightly bluish cast, this probably requires dye.
Surfaces to be painted should be ONLY lightly chromated. I’ve seen this done less commonly on chromated zinc plating than on chromated aluminum.
ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent. Regards, Ted Mooney, P.