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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SC 4 very severe. What process variation would produce these different results?
ASTM B-633 Type II vs. III zinc plating
It still will have Hex Chrome. Zinc plating is usually considered a functional coating, not a decorative one. Surfaces left-bare should be heavily chromated. It definitely implies Hex Chrome. ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent.
Sorry, but if you need one particular look, you must go through the ugly process of maintaining sample boards with acceptable vs. Also, I found out that the casting is painted after plating. Rest in peace, Ken. How do you know if it is supposed to be Zinc Yellow or Zinc Clear? Did you ever get the answers you were looking for? Different brands of chromate conversion chemistry, possibly different plating processes acid zinc vs.
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. Don Penzenik – Elkhart, Indiana. What type of zinc plating bath is your plater using? He passed away May 14, 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.
Obviously, this must be clarified by the customer. Trivalent chromates give paler and lighter finishes; some use metals, some use permanganates, some use dyes, in order to replicate the Hex finish.
It would be “bright, blue” — that is, shiny and metallic but with a bluish rather than a yellowish cast. 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. Is this process done in the United States, and if so by whom?
Perhaps some confusion with Service Condition SC 2 moderatewhich indicates a minimum zinc thickness of 8 microns and is commonly clear chromated Type III. Also, some yellow chromates are clear w.
So if I’m interpreting this correct, there is both a color difference and a salt spray difference. It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. 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.
Does plating make that big a difference knowing that it’s going to be painted also?
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. From beautiful Pine Beach New Jersey: High strength steels tensile strength greater than MPa shall not be electroplated. Regarding the question asked in letter ; Type II zinc plating vs. A light yellow would be better than a clear. Hi, I recently received 2 batches of parts from two asrm platers using this specification.
I’m not a zinc plater, but ‘Type II Clear’ seems self-contradictory. Not the least of which is the environmental regulations impact on the future of the selected finish. A Blue with pale yellow is the best b63-398 for yellow as of now.
Does anybody know this info? The designer and engineer must take into account several considerations to stay at the forefront of the finish potential. I have the exact aatm questions. But if you are looking for something indisputably blue, as opposed to clear with a possible slightly bluish cast, this probably requires dye. Please forgive any resultant repetition or failures of chronological order.
In 24 years I have only been asked this question once before and I presume it involves phosphating over zinc plating for those astj phosphating grammage applications, where normal phosphating will not provide enough zinc phosphate that is required in the deposit. August 31, A. The answer is Yes. The revision addresses RoHS concerns and specifically allows non-hexavalent chromate treatments. III is b633–98 and not expected to hold up as long as the colored II.
ASTM B std: Electrodeposited coating of Zinc
Any information would be well received. Our plater said that he would be willing to go thicker on the clear. It does not cover zinc-coated wire or sheets.
Put b633-988 chromate on light. 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. Corrosion Resistance Requirements Types.