ASTM B standart. DOWNLOAD PDF - KB. Share Embed Donate Description. Designation: B – 99 (Reapproved ). Home; ASTM B standard by ASTM International, 07/01/ View all product details PDF;; Immediate download; $; Add to Cart. Document Center Inc. is an authorized dealer of ASTM standards. This specification covers the requirements for electrodeposited zinc nickel alloy coatings on metals. The zinc nickel coating shall be defined as Class 1.
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ASTM B in English | Standard Specification for Electrodeposited Coatings for Zinc Nickel Alloy Deposits. specifies Zn/Ni per ASTM B - Standard. Specification for Electrodeposited Coatings of Zinc. Nickel Alloy Deposits. ◇ Calls for 12%. B() Standard Specification for Electrodeposited Coatings for Zinc Nickel Alloy Active Standard ASTM B | Developed by Subcommittee: B
FordI and ChryslerI have written specifications to address fastener tightness issues. An in-depth study of the torque and tension properties of the alloys is in progress and will be published in the near future, but preliminary results are presented in Table X. These properties were measured using the Skidmore-Wilhelm instrument. The alloys are not as lubricious as cadmium as evidenced by the higher K values; however, in each case, the torque and tension relationship can be improved to mimic cadmium with the use of the proper dry film lubricant.
SUMMARY The zinc alloy deposits discussed here were developed to provide improved corrosion protection over and above what can be expected from conventional zinc deposits, or in the case of tin-zinc, the deposit is designed to provide improved conductivity.
The use of these alloy deposits has increased in Europe, Asia, and the United States largely in automotive and aerospace applications. In addition, specifications for corrosion testing, torque and tension issues, and hydrogen embrittlement have been examined.
The properties that designers look for include appearance, corrosion protection, good thickness distribution over the part, good alloy distribution over the part, and in some cases, hydrogen embrittlement relief and lubricity.
Processes designed to plate these alloy deposits are both acid and alkaline because each process type has certain advantages. The acid processes are more efficient, but then distribution suffers somewhat. The alkaline processes are less efficient, and as a result, exhibit better distribution. Acid processes are easier to use when the parts are made of cast iron or when parts have been hardened by heat treatment.
Biography References The specifications published by some of the automotive manufacturers for alloys of zinc prove to be good sources of information concerning the 8. It shall be subjected to such cleaning, pickling, and electroplating procedures as are necessary to yield deposits with the desired quality. NOTE 5—The thickness of electrodeposited coatings varies from point to point on the surfaces of a product see Practice B The thickness is less in interior corners and in holes.
Such surfaces are often exempt from thickness requirements. If the full thickness is required in those locations, the electroplater will have to use special techniques that will probably raise the cost of the process.
NOTE 6—The coating requirement of this specification is a minimum. Variation in the thickness from point to point on an article and from article to article in a production lot is inherent in electroplating. Therefore, if all of the articles in a production lot are to meet the thickness requirement, the average coating thickness for the production lot as a whole will be greater than the specified minimum.
NOTE 2—Proper preparatory procedures and thorough cleaning are essential to ensure satisfactory adhesion and corrosion resistance performance of the coating.
Materials used for cleaning should not damage the basis metal, for example by causing defects such as pits, intergranular attack or stress corrosion cracking. It is recommended that the following practices for cleaning, where appropriate, be used: Practices B and B , and Guides B and B Specification B may be consulted for a list of pre-treatments that are widely used. Specification B may be consulted for a list of posttreatments that are widely used. Test Methods 8. The specimen should duplicate the characteristics of the article that influence the property being tested.
For example, a low-carbon steel specimen may represent a brass article when the magnetic thickness test is used see Test Method B The thickness specimen need not be carried through the complete process with the represented article.
If not, introduce it into the process at the point where the coating is applied and carry it through all steps that have a bearing on the coating thickness.
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In rack plating, rack the specimen in the same way with the same distance from and orientation with the anodes and other items in the process as the article it represents. Sampling 7. NOTE 7—Usually, when a collection of coated articles, the inspection lot see 7.
The inspection lot is then classified as complying or not complying with the requirements based on the results of the inspection of the sample. The size of the sample and the criteria of compliance are determined by the application of statistics.
The procedure is known as sampling inspection. Three standards, Test Method B , Guide B , and Test Method B contain sampling plans that are designed for the sampling inspection of coatings.
Test Method B contains four sampling plans, three for use with tests that are nondestructive and one when they are destructive. The downloader and seller may agree on the plan or plans to be used.
If they do not, Test Method B identifies the plan to be used. Guide B provides a large number of plans and also gives guidance in the selection of a plan. When Guide B is specified, the downloader and seller need to agree on the plan to be used. Test Method B can be used only for coating requirements that have a numerical limit, such as a coating thickness. The test must yield a numerical value and certain statistical requirements must be met.
Test Method B contains several plans and also gives instructions for calculating plans to meet special needs. The downloader and the seller may agree on the plan or plans to be used.
NOTE 8—When both destructive and nondestructive tests exist for the measurement of a characteristic, the downloadr needs to state which is to be used so that the proper sampling plan is selected. A test may destroy the coating but in a noncritical area; or, although it may destroy the coating, a tested part can be reclaimed by stripping and recoating. The downloadr needs to state whether the test is to be considered destructive or nondestructive.
NOTE 10—When special test specimens are used to represent coated articles in a thickness test, the specimens will not necessarily have the same thickness and thickness distribution as the articles unless the specimens and the articles are of the same general size and shape.
Therefore, before finished articles can be accepted on the basis of a thickness test performed on special test specimens, the relationship between the thickness on the specimen and the thickness on the part needs to be established.The coating shall be adherent, free from blisters, pits, or discontinuities, and shall be free of cracks in the as plated state.
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When specified in the download order or contract, a report of the test results shall be furnished. These include test analyses and cumulative performance.
Additionally, this Qbank includes audio questions which are a component of the exam. Coating Requirements 6. Have you mastered microbiology yet??