Hello Claudio and Doug, My compliments for an excellent round of questions! Ans: The answer is Yes. ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent. It definitely implies Hex Chrome. Ans: Trivalent chromates give paler and lighter finishes; some use metals, some use permanganates, some use dyes, in order to replicate the Hex finish.
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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. 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. Available colors are iridescent and black Colorless chromate passivation gives corrosion resistance ability of 12 hours according to ASTM B until white spots-intended to parts used in a light corrosive environment —indoor.
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. 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. The electrical resistance of this green layer passivation is very high because it is thick in relative to other passivations 2.
Decorative charastreistics The exterior visual determined according to last layer. The black layer has also additional target —prevention of light reflection from the part and is used for optical parts. Electrical charasteristics As much as the last layer of the passivation is thin the electrical resistivity is low.
Olive green and Black passivation is thick and has high electrical resistance. Iridescent and Colorless passivation is thin and has low electrical resistance.
Garn This standard is not included asfm any packages. Asm htemational takes no positron respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. 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. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For example, a cold-rolled steel Section 11, Robhills Avc. 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. It is recommended that the following.
ASTM B-633 Type II vs. III zinc plating