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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No it does not imply that. The baking treatment shall be done before the application of the supplementary treatments and within 4 h of removal from the last process. The sampling plan used for the inspection atsm the quality coated article shall be agreed upon between the purchaser and producer.
Test Method B contains several plans and also gives instructions for calculating plans to meet special needs.
ASTM B-633 Type II vs. III zinc plating
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. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
It does not cover electrodeposited zinccoated steel wire or sheets see Speci? The black layer has also additional target —prevention of light reflection from the part and is used for optical parts. Does anybody know this info? Iron metals rust relative quickly, even in a non-corrosive environment. The Zinc coating on the steel does not last shiny for long, and so a further thick layer coating is added, called passivation.
B — 07 Standard Speci? I’ve seen this done less commonly on chromated zinc plating than on chromated aluminum. Baked parts shall not crack or fail by fracture when tested in accordance with 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. Surfaces left-bare should be heavily chromated. To minimize your searching efforts and to offer multiple viewpoints, we’ve combined some threads into the dialog you’re viewing.
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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 astn the b633.
That seems a bit discretional to me. 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. Hello Claudio and Doug, My compliments for an excellent round of questions!
Also, I found out that the casting is painted after plating. Please forgive any resultant repetition or failures of chronological order.
The Standard default is gold for type II coatings unless otherwise specified. What do you say? Answer is based upon pre versions of B, III zinc plating A discussion adtm in but continuing through Q.
Electrical charasteristics As much as the last layer of the passivation is thin the electrical resistivity is low. 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.
Obviously, this must be clarified by the customer. Zinc coating with colorless RoHS compliance passivation.
Zinc Plating: ASTM B Type II vs. III
Going with clear will make it difficult to tell what is clear chromated zinc vs. The rust not only harms the aesthetically smooth look, but also its mechanic needs. So if I’m interpreting this correct, there is both a color difference and a salt spray difference.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Different brands of chromate conversion chemistry, possibly different plating processes acid zinc vs.
The separate specimens may also be cut from scrap castings when ferrous alloy castings are being electroplated. Regards, Ted Mooney, P.
What process variation would produce these different results? As the USA moved toward metric fasteners, for a while there was a move to dye them blue.