Zinc [ASTM-B] This specification covers requirements for electrodeposited zinc coatings applied to iron or steel articles. ASTM B ELECTRODEPOSITED COATINGS OF ZINC ON IRON AND STEEL. The coating is made according to demand, where the distribution is as follows. 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).
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Olive green passivation is a chromate passivation in a green hue that gives excellent corrosion resistance ability hours in a salt spray test and is a good base for paint.
Zinc coating with phosphate passivation. This is not considered a decorative finish and will not generate matching parts. Colorful RoHS compliance passivation gives corrosion resistance ability of hours according to ASTM B until white spots-also intended to parts used in a high corrosive environment —outdoor.
The designer and engineer must take into account several considerations to stay at the forefront of the finish potential.
Some of today’s proprietary trivalent chromium coatings are very thin and consequently will not generate a highly saturated color though. II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt spray. I’ve seen this b6333-85 less commonly on chromated zinc plating than on chromated aluminum. Mark Hollenbeck alloys b633-5 Muskegon, Michigan A.
We are getting poor coverage on the as-cast surface of some steel castings using a yellow Zinc chromate. It does not cover zinc-coated wire or sheets.
Put the chromate on light.
Zinc Plating: ASTM B Type II vs. III
There are different passivation colors: No, other colors may not be available if my presumption is right. III zinc plating A discussion started in but continuing through Q. But if you are looking for something indisputably blue, as opposed to satm with a possible slightly bluish cast, this probably requires dye.
All I need to know is what color the types are. Hi, I recently received 2 batches of parts from two separate platers using this specification. So if you need to color match, you need to do it with a requirement for compliance with sample parts — not a verbal description. Certain castings are difficult, if not impossible, to plate in either cyanide or alkaline non-cyanide plating baths.
Could you explain this? A Blue with pale yellow is the best replacement for yellow as of now. Ray Kremer Stellar Solutions, Inc.
Is there any colour difference OR is there any Salt spray difference? The Zinc coating on the steel does not last shiny for long, and so a further thick layer coating is added, called passivation.
I need to specify platings that do not contain Hexavalent Chromium for parts that will be used in the automotive industry. ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent.
Answer is based upon pre versions of B, The black layer has also additional target —prevention of light reflection from the part and is used adtm optical parts.
So if I’m interpreting this correct, there is both a color difference and a salt spray difference. 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 b633-8 how. Also, I found out that the casting is painted after plating. He passed away May 14, I’m not a zinc plater, but ‘Type II Clear’ seems self-contradictory. Corrosion resistance Colorful chromate passivation gives corrosion resistance ability of 96 hours according to ASTM B until white spots-intended to parts used in a high corrosive environment —outdoor.
Kaushik, The “Types” define supplementary finishes to be done after the plating. I am not getting the difference between this. Our Zinc coating is carried out according to: Hello Claudio and Doug, My compliments for an excellent round of questions! The revision addresses RoHS concerns and specifically allows non-hexavalent chromate treatments. A heavy chromate will shear under paint and cause the paint to peel.
Surfaces to be painted should be ONLY lightly chromated.
ASTM B datasheet & applicatoin notes – Datasheet Archive
III is colorless and not expected b633-58 hold up as long as the colored II. The electrical resistance of this green layer passivation is very high because it is thick in relative to other passivations. To me “bright blue” does not usually literally mean “bright blue” like the sky or a robin’s egg.
Going with clear will make it difficult to tell what is clear b633–85 zinc vs. It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. Can anyone give me some direction on how to get the customer to accept going to clear.
What type of zinc plating bath is your plater using? Different brands of chromate conversion chemistry, possibly different plating processes acid zinc vs.
Not the least of which is the environmental regulations impact on the future of the selected finish. The coating is made according to demand, where the distribution is as follows: How do you know if it is supposed to be Zinc Yellow or Zinc Clear?
Until a very few years ago chromate aetm coatings were based on hexavalent chromium, and deposited a thick film h633-85 was relatively easy to dye. To minimize your searching efforts and to offer multiple viewpoints, we’ve combined some threads into the dialog you’re viewing.