1、Designation: E 712 80 (Reapproved 2003)Standard Practice forLaboratory Screening of Metallic Containment Materials forUse With Liquids in Solar Heating and Cooling Systems1This standard is issued under the fixed designation E 712; the number immediately following the designation indicates the year o
2、foriginal adoption or, in the case of revision, the year 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 This practice covers several laboratory test proceduresfo
3、r evaluating corrosion performance of metallic containmentmaterials under conditions similar to those that may occur insolar heating and cooling systems. All test results relate to theperformance of the metallic containment material only as a partof a metal/fluid pair. Performance in these laborator
4、y testprocedures, taken by itself, does not necessarily constitute anadequate basis for acceptance or rejection of a particularmetal/fluid pair in solar heating and cooling systems, either ingeneral or in a particular design. This practice is not intendedto preclude the use of other screening tests,
5、 particularly whenthose tests are designed to more closely simulate field serviceconditions.1.2 This practice describes apparatus and procedures forseveral tests, any one or more of which may be used to evaluatethe deterioration of the metallic containment material in ametal/fluid pair. The procedur
6、es are designed to permit simu-lation, heating, and cooling systems including (1) operating fullflow, (2) stagnant full, (3) stagnant partial fill, and (4) stagnantempty. Particular attention should be directed to properlyreflecting whether the system is open or closed to atmosphere.1.3 This practic
7、e covers the following six tests:Practice A Basic Immersion Test at Atmospheric PressurePractice B Heat-Rejecting Surface Test at Atmospheric PressurePractice C High-Pressure TestPractice D Repeated Dip Dry Test at Atmospheric PressurePractice E Crevice Test at Atmospheric PressurePractice F Tube Lo
8、op Test at Atmospheric Pressure1.4 Practice A is concerned with the interaction of metal andfluid when both are at the same temperature with no heattransfer from one to the other. It is regarded as useful forplumbing, pumps, tanking, etc., but of less significance, takenby itself, for collector pane
9、ls. Practices B and F are concernedwith the deterioration of the metal when there is transfer of heatfrom the metal into the heat transfer fluid. These practices areespecially applicable to the collector panel. Practice C permitsa variety of tests but is especially useful in relation to systemsthat
10、experience high temperatures, or are closed to the atmo-sphere. Practices D and E evaluate specific corrosion problemsthat may be associated with particular metal/fluid pairs andparticular designs of systems and components.1.5 This standard does not purport to address all of thesafety concerns, if a
11、ny, 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. Referenced Documents2.1 ASTM Standards:D 1384 Test Method for Corrosion Test for Engine C
12、oolantsin Glassware2G 1 Practice for Preparing, Cleaning, and Evaluating Cor-rosion Test Specimens3G 48 Test Methods for Pitting and Crevice Corrosion Re-sistance of Stainless Steels and Related Alloys by the Useof Ferric Chloride Solution33. Significance and Use3.1 At this time, none of these tests
13、 has been demonstratedto correlate with field service.3.2 It is essential that consideration be given to the appro-priate pairing of metal and fluid since these procedures do notrestrict the selection of either the containment material or thefluid for testing. Likewise, knowledge of the corrosion pr
14、otec-tion mechanism and the probable mode of failure of aparticular metal is helpful in the selection of test conditions andthe observation, interpretation, and reporting of test results.3.3 The design of solar heating and cooling systemsstrongly affects the applicability of the results of the labor
15、atoryscreening tests. Therefore, the results of these laboratoryprocedures should be confirmed by component and systemstesting under actual or simulated service conditions.3.4 Table 1 is provided to assist in an orderly considerationof the important factors in testing. It is expected that the user1T
16、hese test methods are under the jurisdiction of ASTM Committee E44 onSolar, Geothermal, and Other Alternative Energy Sources and is the directresponsibility of Subcommittee E44.05 on Solar Heating and Cooling Subsystemsand Systems.Current edition approved Feb. 5, 1980. Published April 1980. Original
17、lyapproved in 1980. Last edition approved in 1986 as E 71280(1986).2Annual Book of ASTM Standards, Vol 15.05.3Annual Book of ASTM Standards, Vol 03.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.of the test procedure will investi
18、gate a range of test times andtemperatures for the containment material in a metal/fluid pair,and adjust the time and temperature of testing as necessary.NOTE 1Corrosion, whether general or localized, is a time-dependentphenomenon. This time dependence can show substantial nonlinearity. Forexample,
19、formation of a protective oxide will diminish corrosion withtime, while certain forms of localized attack accelerate with time. Theminimum time required for a test to provide a corrosion rate that can beextrapolated for the prediction of long-term performance varies widely,depending on the selection
20、 of metal and fluid, and on the form of corrosionattack. Therefore, it is not possible to establish a single minimum lengthof test applicable to all materials and conditions. However, it is recom-mended that for the tests described in this practice, a test period of no lessthan 30 days be used. Furt
21、hermore, it is recommended that the effect oftime of testing be evaluated to detect any significant time dependence ofcorrosion attack.3.5 It is essential for the meaningful application of theseprocedures that the length of the test be adequate to detectchanges in the nature of the fluid that might
22、significantly alterthe corrosivity of the fluid. For example, exhaustion ofchemical inhibitor or chemical breakdown of the fluid mayoccur after periods of months in selected cycles of operation.NOTE 2Many fluids that may be considered for solar applicationscontain additives to minimize the corrosivi
23、ty of the fluid. Many suchadditives are useful only within a specific concentration range, and someadditives may actually accelerate corrosion if the concentration fallsbelow a critical level. Depletion kinetics can be a strong function of theexposed metal surface area. Therefore, for tests involvin
24、g fluids with suchadditives, consideration must be given to the ratio of metal surface area tofluid volume as it may relate to an operating system.4. Selection of Materials and Reagents4.1 Any metallic material may be selected for evaluation.The material shall be capable of being described with suff
25、icientaccuracy to permit reproduction of the test.4.2 Any heat-transfer fluid may be selected for evaluation.However, it is expected that the fluid will be selected withconsideration given to possible interactions of material andfluid under the conditions of testing. The fluid should becapable of be
26、ing described chemically, as to its basic compo-nents and the presence or absence of minor components thataffect the interaction with the metal. It is permitted to precon-dition the fluid before testing. Any such preconditioningtreatment shall be described in the report.4.3 Particular attention shal
27、l be directed to avoidance ofmaterials, fluids, or metal/fluid pairs that can be hazardous tothe operator. The flammability, vapor pressure, and toxicity ofthe heat-transfer fluid shall be known prior to initiation oftesting and appropriate precautionary measures shall be takento ensure the safety o
28、f all test personnel.5. Sampling and Test Specimens5.1 The test specimens shall be selected from material thatmay reasonably represent that material as it would be appliedin a solar heating and cooling system.5.2 For laboratory corrosion tests that simulate exposure toservice environments, a commerc
29、ial surface, such as a millfinish, closely resembling the one that would be used inservice, will yield the most significant results. For moresearching tests of either the metal or the environment, standardsurface finishes may be preferred. Ideally, the surface finishshould be recorded in surface rou
30、ghness terms, such as rmsinches.5.3 General Cleaning:5.3.1 General cleaning may be accomplished with a widevariety of cleaning media. Water-based cleaners should befollowed by an alcohol dip after thorough rinsing. Solventcleaners such as petroleum fractions, aromatic hydrocarbons,and chlorinated hy
31、drocarbons are generally acceptable. Chlo-rinated solvents, however, should not be used on titanium,stainless steel, or aluminum. Mechanical cleaning of verysmooth surfaces may be accomplished by the use of a paste ofmagnesium oxide or alumina.5.3.2 Any of the methods suitable for cleaning a givenco
32、rroded specimen may be used to complete the cleaning ofspecimens prior to test, provided that they do not causeTABLE 1 Significant Variables in Evaluation of Containment Material/Heat Transfer Fluid PairsATest AspectVariableTemperature Flow RateI. Operating Conditions of System:A. Operating, full fl
33、owB. Stagnant, fullnormal operatingfluid boiling point without pressurization or no-flow temperature with pressurizationnormal operatingconvectionC. Stagnant, partial fillD. Stagnant, emptysame as stagnant, fullno-flow temperatureconvectionnot applicableII. Test Specimen Design A. flat metal coupleB
34、. metal couple with creviceC. dissimilar metal coupleD. dissimilar metal couple with creviceIII. Fluid Type A. fluid intended for use in systemB. fluid pretreated by thermal exposure or chemical contaminationIV. Test Cycle A. long time, constant temperatureB. cycles of heating, holding, and coolingC
35、. cycles of operating full flow, and stagnationD. cycles of wetting and dryingAIn this table, the subdivisions are not necessarily related in correspondence to their lettering.E 712 80 (2003)2localized attack. The cleaned specimens should be measuredand weighed. Dimensions determined to the third si
36、gnificantfigure and mass determined in the fifth significant figure areusually satisfactory.5.4 Metallurgical ConditionSpecimen preparation maychange the metallurgical condition of the metal. For example,shearing a specimen to size will cold-work and possiblyfracture the edges. The specimen may be t
37、ested in thiscondition if it is believed that such a condition may beencountered in service. In this case, the condition shall bedescribed in the report of results. However, it is recommendedthat changes in metallurgical condition be corrected for cus-tomary testing. For example, sheared edges shoul
38、d be ma-chined or the specimen annealed.5.5 Alternative specimen designs, particularly those incor-porating crevices or metal couplings as may be encountered inapplication, are recommended.5.6 For many metals, electrolytic cleaning is a satisfactorymethod for cleaning after testing. The following me
39、thod istypical:5.6.1 After scrubbing to remove loosely attached corrosionproducts, treat the specimen as a cathode in hot, dilute sulfuricacid under the following conditions.5.6.1.1 Electrolyte Sulfuric acid (H2SO4) (5 mass %).5.6.1.2 Inhibitor0.2 vol % of organic inhibitor (see Note3).5.6.1.3 Anode
40、Carbon or lead (see Note 4).5.6.1.4 CathodeTest specimen.5.6.1.5 Cathode Current Density2000 A/m2.5.6.1.6 Temperature 75C (165F).5.6.1.7 Exposure Period 3 min.NOTE 3Instead of using 0.2 vol % of any proprietary inhibitor and 0.5kg/m3of inhibitors such as diorthotolyl thiourea, quinoline ethiodide or
41、betanaphtol quinoline may be used.NOTE 4If lead anodes are used, lead may deposit on the specimen andcause an error in the mass loss. If the specimen is resistant to nitric acid,the lead may be removed by a flash dip in 1 + 1 nitric acid. Except for thepossible source of error, lead is preferred as
42、an anode as it gives moreefficient corrosion product removal.5.6.2 After the electrolytic treatment, scrub the specimenswith a brush, rinse thoroughly, and dry.5.6.3 It should be noted that this electrolytic treatment mayresult in the redeposition of metal, such as copper, fromreducible corrosion pr
43、oducts, and thus, lower the apparentmass loss.5.7 Chemical cleaning of specimens after testing is satisfac-tory provided the following procedures are used:5.7.1 Copper and Nickel AlloysDip for 1 to 3 min in HCl(1+1)orH2SO4(1 + 10) at room temperature. Scrub lightlywith bristle brush under running wa
44、ter, using fine scouringpowder if needed.5.7.2 Aluminum Alloys Dip for 5 to 10 min in a watersolution containing 2 mass % of chromic acid (chromiumtrioxide, CrCO3) and 5 vol % of orthophosphoric acid (H3PO4,85 %) maintained at 80C (175F). Ultrasonic agitation willfacilitate this procedure. Rinse in
45、water to remove the acid,brush very lightly with a soft bristle brush to remove any loosefilm, and rinse again. If film remains, immerse 1 min inconcentrated nitric acid and repeat previous steps. Nitric acidalone may be used if there are no deposits.5.7.3 Tin AlloysDip for 10 min in boiling trisodi
46、umphosphate solution (15 %). Scrub lightly with bristle brushunder running water and dry.5.7.4 Iron and Steel Suitable methods are as follows:5.7.4.1 Preferably, use electrolytic cleaning (see 5.6).5.7.4.2 Immerse in Clarks solution (hydrochloric acid100 parts, antimonious oxide2 parts, stannous chl
47、oride5parts) for up to 25 min. Solution may be cold, but it should bestirred vigorously.5.7.4.3 Remove scales formed on steel under oxidizingconditions in 15 vol % concentrated phosphoric acid contain-ing 0.15 vol % of organic inhibitor at room temperature.5.7.4.4 Clean stainless steel in 20 % nitri
48、c acid at 60C(140F) for 20 min.5.7.4.5 In place of chemical cleaning use a brass scraper orbrass bristle brush, or both, followed by scrubbing with a wetbristle brush and fine scouring powder.NOTE 5Such vigorous mechanical cleaning is applicable when massloss is large and hence errors in mass loss w
49、ill produce only small errorsin corrosion rates. Blank corrections will be difficult to apply.5.7.4.6 Other methods of cleaning iron and steel includeimmersion in hot sodium hydride, and cathodic pickling inmolten caustic soda.NOTE 6These methods may be hazardous to personnel. They shouldnot be carried out by untrained personnel or without supervision.5.7.5 After cleaning and thorough rinsing, dry and weighthe samples.6. Calculations and Interpretation of Results6.1 The deterioration of the containment material shall bedetermined by measurement of mass loss a
