He is asking for more info on the difference between ASTM B [link by ed. to spec at TechStreet] type II and type III. Can anyone give me some direction on. ASTM B Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel. This specification covers requirements for electrodeposited. ASTM B Thickness classes for coatings: KEY: Classification #, Service condition, Thickness Fe/Zn 25, SC4 (very severe), 25um or ″ Fe/Zn 12, SC3.
|Published (Last):||7 April 2009|
|PDF File Size:||12.75 Mb|
|ePub File Size:||10.69 Mb|
|Price:||Free* [*Free Regsitration Required]|
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.
The values are only relative, since individual studies in various parts of the world have resulted in figures which vary widely from these averages. No it does not imply that. A heavy chromate will shear under paint and cause the paint to peel. While thc conditions of exposure and uses of electroplated metal are so varied that it is not definitely possible to predict the exact life of articles protected by a coating of a given thickness, those usirig ziric coatings can draw on the wealth of practical b63311 at atm, supplemented by results of corrosion tests carried out over the years.
Until a very few years ago chromate conversion coatings were based on hexavalent chromium, and deposited a thick film that was relatively easy to dye. Also, some yellow chromates are clear w. Our plater said that he would be willing to go thicker on the clear.
The asym entries are somewhat dated: Tlle following data, based on worldwide testing, can be used to coinpare the behavior of electrodeposited coatings of zinc in various atmospheres. The appearance of corrosion products when examined with eyesight at normal reading distance shall be cause for rejection, except that white corrosion b633-111 6 mm or less from the edges of specimens shall not constitute failure.
It’s not possible to diagnose a finishing astn or the hazards of an operation via these pages. How do you know if it is supposed to be Zinc Aztm or Zinc Clear? A light yellow would be better than a clear. Fnr thesc reasons a flat test panel should be usai to evaluate the prwess capability and the angle should be controlled to cnsure consistent Ille: That seems a bit discretional to me.
ASTM B-633 Type II vs. III zinc plating
Hello Claudio aetm Doug, My asym for an excellent round of questions! No, other colors may not be available if my presumption is right. So if you need to color match, you need to do it with a requirement for compliance with sample parts — not a verbal description. Is this process done in the United States, and if so by whom?
As a result of large-scale and long-range tests conducted by ASTM and other organizations, tllere is excellent information on the corrosion behavior of zinc arid zinc coatings. Except as otherwise spaififii in the contract or order, the supplier may use his own or any other facilities suitable for thc performance of the inspection requirements specified herein, unless disapproved by the purchaser.
Corrosion Resistance Requirements Types. What type of zinc plating bath is your plater using? This guide provides for two plans: If these heat treatments are not required, the purchaser shall spcciljr in their exception 5 2 5.
Electroplated springs and other puts subject to flexure sliall not be Ilcxed before the hydrogen embrittlement relief treatment. But if you are looking for something indisputably blue, as opposed to clear with a possible slightly bluish cast, this probably requires dye.
ASTM B – 11 Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel
B633-1 B and all other worldwide standards were written around the time when no one spoke about trivalent. All I need to know is what color the types are.
Rcfcrcnccd 1 ocuments 2. The sampling plan used for the inspection of the qualily coated article shall be agreed upon betweet1 the purchaser and producer. Standards Subsctiption may be the perfect solution.
I have the exact same questions. ASTM htemational takes no positron respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. We are getting poor coverage on the as-cast surface of some steel castings b363-11 a asym Zinc chromate. As the USA moved toward metric fasteners, for a while there was a move to dye them blue.
I’ve seen this done less commonly on chromated zinc plating than on chromated aluminum. Can anyone give me some direction on how to get the customer to accept going to clear. It is recommended that the following. Zinc and Zinc alloys, such as zinc-nickel will surely play a more significant role as metals such as Cadmium are destined for the elements’ Valhalla. Answer is based upon pre versions of Basm, It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of ashm limitations prior to use.
Zinc Plating: ASTM B Type II vs. III
The procedure is known as sampling inspection. Tesl Method 13 provides a default plan if one is no1 specified. II says “colored chromate coatings” meeting 96 hours of salt spray, and III says “colorless chromate conversion coatings” meeting 12 hours of salt spray.
To minimize problems of this sort, the specifications covering the basis matcrial on the item to be electroplated shall contain appropriate limitations to such basis metal conditions. To minimize your searching efforts and to offer multiple viewpoints, we’ve combined some threads into the dialog you’re viewing. A Blue with pale yellow is the best replacement for yellow as of now. Could you explain this?
The answer is Yes. 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. The designer and engineer must take into account several considerations to stay at the forefront of the finish potential. Does plating make that big a difference knowing that it’s going to be painted also?
Ken Vlach – Goleta, California. The Standard default is gold for type II coatings unless otherwise specified. Ilie ucatlnent required for conversion to l j p e IV shall be in accordance with Guide 1