ASTM B Type II and III zinc chromate plating Q&A’s. greater corrosion resistance is required, e.g., for SC3 & SC4 (13 & 25 microns zinc, respectively). Blue/Zinc. Blue/Zinc. Yellow/Zinc. Yellow/Zinc. ASTM B Type II SC 3 (FE/ZN 13). Type II SC 2 (FE/ZN 8). Type II SC 1 (FE/ZN 5). Type III SC 3(FE/ZN 13). ASTM A/AM Low and Intermediate Tensile Strength Carbon Steel Plates .. ASTM B Electrodeposited Coatings of Zinc on Iron and Steel.
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Iridescent and Colorless passivation is thin and has low electrical resistance. It definitely implies Hex Chrome. I have the exact same questions.
It would be “bright, blue” — that is, shiny and metallic but with a bluish rather than a yellowish cast. Our Zinc coating asgm carried out according to: What do you say? The part is currently being produced in China and my local 31 are suggesting a dye to get a blue color.
The problem may not be with the chromate at all. Ray Kremer Stellar Solutions, Inc. Olive Drab chromate is hrs.
I need to specify platings that do not contain Hexavalent Chromium for parts that will be used in the automotive industry. There are different passivation colors: That seems a bit discretional to me.
Obviously, this must be clarified by the customer. The exterior visual determined according to last layer.
The electrical resistance of this green layer passivation is very high because it is thick in relative to other passivations. I am not getting the difference between this. Decorative charastreistics The exterior visual determined according to last layer. ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent. Zinc coating with colorless RoHS compliance passivation.
Our plater would like to go to a clear zinc, but our customer is under the assumption that the clear will not b633 as good a job with corrosion resistance and salt spray life.
So if you need to color match, you need to do it asym a requirement for compliance with sample parts — not a verbal description. To calculate it is very difficult, as the plating is astj few molecules thick. 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. To minimize your searching efforts and to offer multiple viewpoints, we’ve combined some threads into the dialog you’re viewing.
So if I’m interpreting this correct, there is both a color difference and a salt spray difference. A light yellow would be better than a clear. Hello Claudio and Doug, My compliments for an excellent round of questions! Yellow-iridescent Black Olive Green.
Zinc coating with phosphate passivation. Trivalent chromates give paler and lighter finishes; some use metals, some use permanganates, some use dyes, in order to replicate the Hex finish.
August 31, A. He passed away May 14, Electrical qstm As much as the last layer of the passivation is thin the electrical resistivity is low. III is colorless and not expected to hold up as long as the colored II. The type of passivation is determined according to the required characteristics, and is divided into groups:. The black layer has also additional target —prevention of light reflection b633 the part and is used for optical parts. 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.
Mark Hollenbeck alloys – Muskegon, Michigan A. Put the chromate on light. 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 spec.
ASTM B-633 Type II vs. III zinc plating
Zinc coating with colorful RoHS compliance passivation. Surfaces left-bare should be heavily chromated. Going with clear will make it difficult to tell what is clear chromated zinc vs.
As much as the last layer of the passivation is thin the electrical resistivity is low. The revision addresses RoHS concerns and specifically allows non-hexavalent chromate treatments. It still will have Hex Chrome. Perhaps some confusion with Service Condition SC 2 moderatewhich indicates a minimum zinc thickness of 8 microns bb633 is commonly clear chromated Type III.
Zinc Plating: ASTM B Type II vs. III
As the USA moved toward metric fasteners, for a while there was a move to dye them blue. Please forgive any resultant repetition or failures of chronological order. Is this process done in the United States, and if so by whom? 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. The rust not only harms the aesthetically smooth look, but also its mechanic needs.
This applies to all metals. Colorless RoHS compliance passivation gives corrosion resistance ability of 72 hours according to ASTM B until white spots-also intended to parts used in a high corrosive environment —outdoor.