1、Designation:C28313(Reapproved 2017)Standard Test Methods forResistance of Porcelain Enameled Utensils to Boiling Acid1This standard is issued under the fixed designation C283;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year o
2、f last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe described method furnishes a means of quantitatively testing and grading glossy porcelainenamels with respect to the
3、ir resistance to boiling citric acid at room temperature.Citric acid has beenselected because it is the most common and one of the more severe of the food acids in its action onconventional porcelain enamels.1.Scope1.1 These test methods cover the determination of theresistance of porcelain enamel c
4、oatings used on utensils toattack by boiling acid.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport t
5、o 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 health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor
6、-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Significance and Use2.1 Test Met
7、hod A provides the producers of porcelainenameled utensils with a quality control method of testing forresistance to boiling acid for parts randomly selected from theproduction line.2.2 Test Method B provides the supplier of porcelainenamel raw materials with a laboratory method for testing theresis
8、tance of different coatings(intended for use on utensils)toboiling acid.TEST METHOD A3.Apparatus3.1 Hot Plate,capable of maintaining over its entire surfacea uniform temperature that will keep the test solution at arolling boil(see section 7.5).The heating element shouldoccupy an area at least 8 in.
9、(203 mm)in diameter.3.2 Chemical GlasswareBeakers,a desiccator,and a500-mL graduated cylinder.3.3 Drier,capable of maintaining a temperature of at least220F(104C).3.4 Boiling Acid Resistance Apparatus,as shown in Fig.1.Three sets will be required.3.5 Cutting Equipment,suitable for cutting a 314-in.(
10、82-mm)diameter plate from the bottom of a porcelain-enameledsteel utensil,as follows:3.5.1 Punch and Die(Fig.2),3.5.2 Shears,3.5.3 Abrasive Cut-off Wheel,3.5.4 Cutting Torch,or3.5.5 Any Other Suitable Equipment3.6 Analytical Balance,having a sensitivity of 0.0001 g.4.Reagent4.1 The test solution sha
11、ll contain 6 g of ACS grade citricacid per 94 g of distilled water and shall be prepared fresh foreach test.5.Test Specimens5.1 The test specimens shall consist of three plates,314in.(82 mm)in diameter,cut from the bottoms of three identicalutensils.1These test methods are under the jurisdiction of
12、ASTM Committee B08 onMetallic and Inorganic Coatings and are the direct responsibility of SubcommitteeB08.12 on Materials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved May 1,2017.Published May 2017.Originallyapproved in 1951.Last previous edition approved in 2013 as C283 13
13、.DOI:10.1520/C0283-13R17.Test Method A is based on the boiling acid resistance test developed by theEnameled Utensil Manufacturers Council;see Section 16 of Commercial StandardCS100-47,Porcelain Enameled Steel Utensils,United States Department of Com-merce.Copyright ASTM International,100 Barr Harbo
14、r Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations is
15、sued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 NOTE1“Identical utensils”signifies utensils of the same size,shape,and finish.6.Preparation of Test Specimens6.1 After the test specimens have been cut from the utensils,file their edges with a triangular file to remove
16、 any looseenamel chips.6.2 Thoroughly wash the test specimens with soap andwater to remove any grease picked up in handling.Rinse withdistilled water.Place the specimens in a drier at 220F(104C).After 10 min,remove the test specimens and place them in adesiccator containing calcium chloride.7.Procedure7.1 Level the hot plate,turn the switch on in the high heatposition,and allow to preheat for at least 1 h to obtain auniform temperature over the entire heating element.7.2 Remove the test specimen
