ASTM_C_614_-_10_2015.pdf

Designation:C61410(Reapproved 2015)Standard Test Method forAlkali Resistance of Porcelain Enamels1This standard is issued under the fixed designation C614;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONAlthough all porcelain enamels are highly resistant to attack by cold alkaline solutions,somecompositions are affected by hot solutions of the type encountered in automatic laundry anddishwashing equipment.Tests to eliminate porcelain enamels of poor resistance have been developedand used by various laboratories.In general,these tests consist of subjecting specimens to a boilingsolution of either sodium pyrophosphate or sodium hydroxide for a period of two or more hours.Thespecimens are weighed before and after exposure to the test treatment and the loss-in-weight is takenas a measure of alkali attack.In some tests representing milder exposure conditions,the 45 degreespecular gloss is measured before and after exposure and the percentage of initial gloss retained is usedas an indicator of alkali resistance.While such tests have served a useful purpose in developing moreresistant porcelain enamel compositions and in manufacturing control operations,agreement betweenlaboratories has left something to be desired.The present test was designed to provide thereproducibility between laboratories that is so essential to any standard test procedure.1.Scope1.1 This test method2covers the measurement of the resis-tance of a porcelain enamel to a hot solution of tetrasodiumpyrophosphate.Although the specific alkali mentioned hereinis tetrasodium pyrophosphate the equipment and techniques areequally applicable to other alkali solutions.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 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 health practices and determine the applica-bility of regulatory limitations prior to use.2.Significance and Use2.1 This test method is intended specifically for testing theresistance to alkaline attack of porcelain enamels to be used asa final finish on washing machines,dishwashers,combinationwasher-dryers,and similar appliances where the surface isnormally exposed to an alkaline environment at elevatedtemperatures.3.Apparatus3.1 Test Chamber,of a type illustrated in Fig.1,Fig.3,andFig.6.This part of the equipment consists of a stainless steelbeaker fitted with an O-ring sealed cover which supports animmersion heater,a stirring device,thermometer and thermis-tor wells;three specimen holders;a reflux condenser;a flowchanneling shield to slide over and be supported by theimmersion heater;and a stirring motor.3The beaker,heatersheath,stirring device,thermometer and thermistor wells,specimen holders,and the flow channeling shield shall be madefrom stainless steel alloys from the AISI 300 Series.3.2 Temperature Controller,thermistor-actuated,capable ofmaintaining the temperature of the alkali solution in the beakerat 96.00 6 0.20C.3.3 Thermometer,calibrated,approximately 15 in.(380mm)long and932in.(7.1 mm)in diameter,with 0.1 divisions.3.4 Drying Oven,electrically heated.3.5 Balance,having a sensitivity of 0.1 mg and a capacity ofnot less than 200 g.1This test 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 May 1,2015.Published May 2015.Originallyapproved in 1968.Last previous edition approved in 2011 as C614 10(2011).DOI:10.1520/C0614-10R15.2This test was developed at the National Bureau of Standards under thesponsorship of The Porcelain Enamel Institute,Inc.,and published as P.E.I.Bulletin T-25.3See the appendix for drawings of the equipment.This equipment may bepurchased from the Hoover Instrument Service,Inc.,401 N.Home Rd.,Mansfield,OH 44906.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.6 Desiccator.3.7 Hot Plate,or burner suitable for heating the test solu-tion.3.8 Sponge,soft,cellulose.3.9 Aluminum Alloy Sheets,approximately 312by 312by18in.(89 by 89 by 3.1 mm).4.Reagents and Materials4.1 Tetrasodium Pyrophosphate,hydrated(Na4P2O710H2O),recrystallized,reagent grade.4.2 Trisodium Phosphate(Na3PO412H2O).5.Test Specimens5.1Preparation of Specimens The test specimens shallbe 312in.(89 mm)square and may be prepared by enamelingmetal blanks of that size or by cutting from a larger piece.Hanging holes,