ASTM B Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel. Buy ASTM B SPECIFICATION FOR ELECTRODEPOSITED COATINGS OF ZINC ON IRON AND STEEL from SAI Global. ASTM B Type II and III zinc chromate plating Q&A’s. In my opinion a Mil-C- [link is to free spec at Defense Logistics Agency, ] plating.
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Sorry, but if you need one particular look, you must go through the ugly process of maintaining sample boards with acceptable vs. If heavier coatings are required, allowance for the deposit buildup must be made during the manufacture of the threaded articles.
If these heat treatments are not required, ffee purchaser shall specify in the ordering information their exception 5. I am not getting the difference between this.
I need to specify platings that do not frew Hexavalent Chromium for parts that will be used in the automotive industry. 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. It still ffee have Hex Chrome. NOTE 1—Surfaces should be activated as soon as possible following baking and handled carefully to avoid contamination and maintain an active surface for post processing.
Test Method B contains several plans and also gives instructions for calculating plans to meet special needs. Zinc coating with colorful chromate passivation.
ASTM B-633 Type II vs. III zinc plating
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. Guide B provides a default plan if one is not speci? Properly performed, statisitical process control will assure coated products frew satisfactory quality and will assure the amount of acceptance inspection. ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent.
The electrical resistance of this green layer passivation is very high because it is thick in relative to other passivations. Put the chromate on light.
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. III is colorless and not expected to hold up as long as the colored II. Please forgive any resultant repetition or failures of chronological order.
Zinc Plating: ASTM B Type II vs. III
The revision addresses RoHS concerns and specifically allows non-hexavalent chromate treatments. As a result of large-scale and long-range tests conducted by ASTM and other organizations, there is excellent information on the corrosion behavior of zinc and zinc coatings.
We are getting poor coverage on freee as-cast surface of some steel castings using a yellow Zinc chromate. This is not considered a decorative finish and will not generate matching parts.
Except as otherwise speci? 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.
Does plating make that big a difference knowing that it’s going to be painted also? A light yellow would be better than a clear. That seems a bit discretional to me. This guide provides for two plans: 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.
Answer is based upon pre versions of B, August 31, A. I’m not a zinc plater, but ‘Type II Clear’ seems self-contradictory. Iron metals rust relative quickly, even in a non-corrosive environment.
Did you ever get the answers you were looking for? Also, I found out that the casting is painted after plating. 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. No, other colors may not be available if my presumption is right.