1、Designation: B 916 01 (Reapproved 2007)Standard Test Method forAdherence of Porcelain Enamel Coatings to Sheet Metal1This standard is issued under the fixed designation B 916; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 The scope of this test method is:1.1.1 To determine quantitatively the amount of enamelremaining after the porce
3、lain enamel coating specimen hasbeen deformed;1.1.2 To standardize the deformation parameters for testingadherence of porcelain enamel to sheet metal; and,1.1.3 To provide a quantitative adherence rating scale forcomparison to reference standards.1.2 This adherence test method is applicable to porce
4、lainenamel coatings on substrates from 18 to 24 gauge (0.0478 to0.025 in. or from 1.214 to 0.654 mm).1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and hea
5、lth practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 The measurement of adherence in porcelain enamelsystems, such as ground coat, ground coat/cover coat, anddirect-on cover-coat enamels, is an important procedure formonitoring process vari
6、ables in metal preparation, enamelapplication thickness, steel selection, and enamel selection, aswell as assuring the ultimate quality of the finished product.3. Apparatus3.1 Drop Weight Deformation Device2, see Figs. 1 and 2.3.2 The drop weight deformation device as shown in Fig. 1shall impart a s
7、ingle impact blow from a hemisphericalindenter to a coated specimen supported over a sharp-edgedbottomless die. The area of the deformation and the concomi-cant damage to the coating is largely influenced by the size ofthe hemispherical indenter; the die opening size and edgesharpness; and, the ener
8、gy of the blow at impact.3.3 A satisfactory degree of deformation and damage areobtained if the conditions in 3.2 use the following parameters:0.50-in. (12.7-mm) diameter hemispherical indenter, 0.75-in.(19.1-mm) diameter bottomless die (lower plunger guide inFig. 1) with sharp edge, and 80in./lb (9
9、.03J) energy atimpact.3.4 Deformation Devices, of other designs may be usedprovided that the parameters in 3.3 are used.3.5 Adherence Reference Standards, see 7.1.4. Test Specimens4.1 The test specimens shall be flat enameled panels not lessin size than 4 in.2(101.6 mm2). Larger sizes and shapes may
10、 beused provided that a flat surface can be held firmly against andparallel to the lower plunger guide during deformation.5. Safety Precautions5.1 During the procedure in 6.1, fine enameled chips may bereleased with some force from the steel surface; therefore, it isrecommended that personnel in the
11、 immediate vicinity of thetest wear safety goggles.6. Procedure6.1 Specimen DeformationThe hammer weight of thesuggested drop weight device is 5 lb (2268 g), which requiresa 16-in. (406.4-mm) drop distance to yield the specified80-in./lb (9.03-J) energy at impact. The hammer weight of thedrop weight
12、 device may range from 2 to 8 lb (907 to 3629 g).If the hammer weight is within this range, but not 5 lb,calculate the drop distance to yield 80 in./lbf of energy atimpact. The center of the area to be deformed shall be at least112 in. (38.1 mm) from the edge of the specimen. If two ormore deformati
13、ons are made on a single specimen, place themat least 3 in. (76.2 mm) between centers and average and treatthe measurements on them as a single measurement. Raise andsecure the hammer to obtain the required drop distance. Holdthe specimen firmly against and parallel to the top surface ofthe die with
14、 the enameled side up and release the hammer.6.2 The specified drop weight device is provided with aspring to limit the indenter to a single impact blow against thespecimen. If the device to be used is not designed in this way,use another means or procedure to avoid a restrike of theindenter.1This t
15、est method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.12 onMaterials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved March 1, 2007. Published March 2007. Originallyapproved in 2001. Las
16、t previous edition approved in 2001 as B 916 01.2A drop weight device that has been found suitable is available from PacificScientific Co., Gardner/Neotech Instrument Div., 2431 Linden Lane, Silver Spring,MD 20910.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
17、PA 19428-2959, United States.6.3 A visual examination of the impact area is then made.Evaluation of the degree of adherence obtained is judged by theamount of glass retained in the impact area.7. Rating of Adherence7.1 Examine the impacted area and compare to the follow-ing reference standards (see
18、Figs. 3 and 4):0 = No adherenceonly shiny metal showing, and enamel may beflaking off beyond the impact area.1 = Poor adherencevery little glass adhering, less than 10 %, andonly at the outer edges of the impact area.2 = Fair adherenceglass particles adhering in at least 25 to 30 %of the impact area
19、.3 = Good adherenceglass particles adhering in at least 50 to 60 %of the impact area.4 = Very good adherenceglass particles adhering in at least 70 to80 % of the impact area.5 = Excellent adherenceglass particles covering almost all of theimpact areaat least 90 %.7.2 Report adherence rating, estimat
20、ed to the nearest 0.5.8. Referee Method8.1 Since adherence depends on factors other than theenamel, that is, steel, firing, and metal preparation, in cases ofdisputed results, a direct comparison should be made betweenthe test enamel known to have acceptable adherence by coatingone-half of a panel w
21、ith each of the enamels and comparingresults as in 7.1.9. Precision and Bias9.1 The precision and bias of this test method is beingestablished.10. Keywords10.1 adherence; porcelain enamel coatings; sheet metalFIG. 1 Drawing of Suitable Drop Weight DeviceB 916 01 (2007)2FIG. 2 Drop Weight Adherence T
22、esterB 916 01 (2007)3Note: See Section 7 for guide to numbers.FIG. 3 Two Coat-One Fire Bond ClassificationB 916 01 (2007)4ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expre
23、ssly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised
24、, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may a
25、ttend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States
26、. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).Note: See Section 7 for guide to numbers.FIG. 4 One Coat-Ground Coat Bond ClassificationB 916 01 (2007)5
