ASTM B (Reapproved )_能源/化工_工程科技_专业资料。 Designation: B – 97 (Reapproved ) Standard Speci?cation for. This ASTM B specification covers the requirements for electroplated nickel coatings applied to metal products for engineering applications. Bright Nickel Plating. ASTM B, AMS-QQ-N bright nickel plated electrical components. At APP we do bright nickel plating, it is widely used for decorative.
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B — 97 Reapproved Standard Speci? ASTM B rp ASTM B A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. Typical mechanical properties of nickel electroplated from these baths, and the combined effect of bath operation and solution composition variables on the mechanical properties of the electrodeposit are given in Guide B When electroplated nickel is required to have higher hardnesses, greater wear resistance, certain residual stress values and certain leveling characteristics, sulfur and other substances are incorporated in the nickel deposit through the use of certain addition agents in the electroplating solution.
For the effect of such additives, see Section 4 and Annex A3. Cobalt salts are sometimes added to the plating solution to produce harder nickel alloy deposits. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Current edition approved Feb.
Originally approved in Last previous edition approved in as B — When necessary, the signi?
NOTE 2—The thickness of the electrodeposit in holes, corners, recesses, and other areas where thickness cannot be controlled under normal electroplating conditions shall be speci? NOTE 3—When a deposit of controlled thickness is required in holes, corners, recesses, and similar areas, special racking, auxiliary anodes or shielding will be necessary.
NOTE 4—Good adhesion of electroplated nickel to stainless steels and high alloy steels usually requires a preliminary strike of electrodeposited nickel.
The recommended practices for the preparation of and electroplating on stainless steels and nickel alloys are given in Practices B and Brespectively.
Class 5 25 50 X Minimum Nickel Thickness,? There are practical limits to nickel thickness and uniformity of thickness distribution caused by the size and geometric con? Identify the substrate material by alloy identi? NOTE 6—Electroplating on hardened high alloy and high carbon steels can reduce the fatigue strength of the metal parts.
This must be considered if the parts will be subjected to repeated applications of complex load patterns in service. Shot peening of signi? Also, reduction in the fatigue life of nickel-electroplated steels can be reduced by considering the relations among the variables that in?
However, these b6889 not normal in the treatment steps preceding the application of the? When they are desired they must be stated in the purchase order see 5. Visual defects are de? The boundaries of electroplating that cover only a portion of the surface shall, after?
Imperfections and variations in appearance in the coating that arise from surface conditions of the basis metal scratches, pores, roll marks, inclusions, etc.
It is recommended that the speci? NOTE 8—The coating thickness requirements of this speci? Variation in the coating thickness from point to point on a coated article is an inherent characteristic of the electroplating process.
Therefore, the coating thickness will have to exceed aetm speci? Hence, in most cases, the average coating thickness on an article will be greater than the speci? In addition, the average coating thickness on articles will vary from article to article within a production lot.
Therefore, if all of the articles in a production lot are to meet the n689 requirement, the average coating thickness for the production lot as a whole will be greater that the average necessary to assure that a single article meets the requirement.
ASTM B689 – 97(2018)e1
Parts having a hardness greater than 35 HRC equivalent to a tensile strength of MPa or greater that have been acid-stripped for recoating shall be rebaked for embrittlement relief see 6. Stress relieving after stripping is not necessary if the stripping is done anodically in an alkaline solution. Contact marks shall be minimized in size and frequency. When contacts must be located on signi? Electrodeposited nickel that is to be? NOTE 9—Some contemporary packaging materials may emit fumes that are deleterious to the surface of the coating.
The criterion of acceptance is that thickness on the specimen that corresponds to the required thickness on the article. Microscopical method Coulometric method Nondestructive Methods: Test Method B Magnetic should not be used for thicknesses less than 10? Test Method B X-ray is instrument-dependent with regard to accuracy with increasing nickel thicknesses. NOTE 12—Since many factors in? Type 2 nickel coatings produced with certain organic additives can exhibit signi?
Thickness measurements with the microscopical method can show large differences on these rough pro? NOTE 10—Test specimens often are used to represent the coated articles in a test if the articles are of a size, shape, or material that is not suitable for the test, or if it is preferred not to submit articles to a destructive test because, for example, the articles are expensive or few in number. The specimen should duplicate the characteristics of the article that in?
For example, a low-carbon steel specimen may represent a brass article when the magnetic thickness test is used Test Method B The thickness specimen need not be carried through the complete process with the represented article. If not, it shall be introduced into the process at the point where the coating is applied and it shall be carried through all steps that have a bearing on the coating thickness.
In rack plating, the specimen shall be racked 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.
NOTE 11—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. The test selected should take into consideration the size, shape, or thickness of the part.
Adhesion tests may at times fail to detect adhesion failure; subsequent fabrication may reveal poor or inadequate adhesion, which shall be cause for rejection. NOTE 13—Adhesion is in? The part fails if more than the number of pores speci? Also refer to Guide B for more information. NOTE 14—When both destructive and non-destructive tests exist for the measurement of a characteristic, the purchaser 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 non-critical area; or, although it may destroy the coating, a tested part can be reclaimed by stripping and recoating.
The purchaser needs to state whether the test is to be considered destructive or non-destructive. Methods B can be used only for coating requirements that have numerical limit, such as coating thickness.
The test must yield a numerical value and certain statistical requirements must be met. Methods B contains several plans and also gives instructions for calculating plans to meet special needs. The buyer and the seller may agree on the plan or plans to be used. If they do not, Methods B identi? NOTE 15—Usually, when a collection of aatm articles, the inspection lot 8. The inspection lot is then classi? 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 BGuide Band Methods B contain sampling plans that are designed for the sampling inspection of coatings.
ASTM B – 97()e1 – Standard Specification for Electroplated Engineering Nickel Coatings
Test Method B contains four sampling plans, three for use with tests that are non-destructive and one when they are destructive. The buyer and seller may agree on the plan or plans to be used.
If they do not, Test Method B identi? Guide B provides a large number atsm plans and also gives guidance in the selection of a plan. When Guide B is speci? Rejection and Rehearing 9. Rejection shall be reported to the producer or supplier promptly, and in writing.
In case of dissatisfaction with the results of a test, the producer or supplier may make a claim for b6889 rehearing. Finishes that show imperfections during subsequent manufacturing operations may be rejected. The purchaser may similarly require that a report of the test results be furnished. It is noncorrosive to nickel. The pH of the water shall be maintained between 6. Additives required for pH control shall be noncorrosive to nickel and shall be approved by the purchaser, for example, pH can be adjusted by introducing CO2 or by additions of H2SO4 or acetic acid, or NaOH.
A source of oil-free air shall be available to aerate the water with agitation vigorous enough to prevent air bubbles from clinging to signi?
This temperature shall be maintained during the sstm test period. At the end of the test period, remove the part from the hot water, and allow the part to drain and dry. Oil-free air pressure may be used b69 speed the drying. Black spots and red rust indicate basis metal corrosion or porosity. The test is very sensitive to the super? Just before use, immerse the dry? Allow 10 min contact time for the test period see Annex A2. Remove the papers at the end of the contact period, and place at once into solution C.
Nickel thickness generally exceeds 5?