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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How do you know if it is supposed to be Zinc Yellow or Zinc Clear?
Zinc coating with colorful RoHS compliance passivation. It still will have Hex Chrome. The following data, based on worldwide testing, can be used to compare the behavior of electrodeposited coatings of zinc in various atmospheres. Did you ever get the answers you were looking for? Zinc coating with colorful chromate passivation. Is there any colour difference OR is there any Salt spray difference?
Try using an acid zinc chloride bath and see if the casting covers. No, other colors may not be available if my presumption is right. Zinc coating with colorless RoHS compliance passivation. The Zinc coating provides a smooth look as well as good anti-corrosive protection. A heavy chromate will shear under paint and cause the paint to peel.
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. Zinc coating with phosphate passivation. The coating shall not be stained or discolored.
Due to the impracticality of forging or casting separate test specimens, hot-rolled steel specimens may be used to represent forged and cast steel articles. 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.
Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
Answer is based upon pre versions of B, As the USA moved toward metric fasteners, for a while there was a move to dye them blue. Can anyone give me some direction on how to get the customer to accept going to clear. Baked parts shall not crack or fail by fracture when tested in accordance with The Standard default is gold for type II coatings unless otherwise specified.
The purchaser may similarly require that a report of the test results be furnished. The size of the sample and the criteria for compliance are determined by the application of statistics. III is colorless and not expected to hold up as long as the colored II. When such areas frse designated, and thus made subject to minimum thickness requirements, the purchaser and the manufacturer shall recognize the necessity for either thicker deposits on other areas or for special racking.
Regards, Ted Mooney, P. Iron qstm rust relative quickly, even in a non-corrosive environment. Mark Hollenbeck alloys – Muskegon, Michigan A. It would be “bright, blue” — that is, shiny and metallic but with a bluish rather than b6333 yellowish cast. ASTM B and all other worldwide standards were written around the time when no one spoke about trivalent.
Also, I found out that the casting is painted after plating. Conditions affecting the electroplating of specimens, including the spacing, plating media, bath agitation, temperature, etc. Surfaces to be painted should be ONLY lightly chromated. Olive green and Black passivation is thick and has high electrical b63.
Perhaps some confusion with Service Condition SC 2 moderatewhich indicates a minimum zinc thickness of 8 microns and is commonly clear chromated Type III. It definitely implies Hex Chrome. If heavier coatings are required, allowance for the deposit buildup must be made during the manufacture of the threaded articles.
Zinc Plating: ASTM B Type II vs. III
The revision addresses RoHS concerns and specifically allows non-hexavalent chromate treatments. The inspection lot is then classi? Subject the selected samples to the salt spray test; the length of time to be applicable for the type of supplementary coating shall be in accordance with the requirements of 7.
II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt asttm. 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.
I’ve seen this done less commonly on chromated zinc plating than on chromated aluminum. A number in parentheses indicates the year of last reapproval. The type of passivation is determined according to the required characteristics, and is divided into groups:. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every? They may be reconsidered for inspection in accordance with Test Xstm B To minimize your searching efforts and to offer multiple viewpoints, we’ve combined some threads into the dialog you’re viewing.
Surfaces left-bare should asrm heavily chromated. Iridescent and Colorless passivation is thin and has low electrical resistance. To minimize problems of this sort, the speci? Yellow-iridescent Black Olive Green. Aatm Vlach – Goleta, California. The rust not only harms the aesthetically smooth look, but also its mechanic needs. What process variation would produce these different results?