1、Designation: E 745 80 (Reapproved 2003)Standard Practices forSimulated Service Testing for Corrosion of MetallicContainment Materials for Use With Heat-Transfer Fluids inSolar Heating and Cooling Systems1This standard is issued under the fixed designation E 745; the number immediately following the
2、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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These practices cover tes
3、t procedures simulating fieldservice for evaluating the performance under corrosive condi-tions of metallic containment materials in solar heating andcooling systems. All test results relate to the performance of themetallic containment material only as a part of a metal/fluidpair. Performance in th
4、ese test procedures, taken by itself, doesnot necessarily constitute an adequate basis for acceptance orrejection of a particular metal/fluid pair in solar heating andcooling systems, either in general or in a particular design.1.2 These practices describe test procedures used to evalu-ate the resis
5、tance to deterioration of metallic containmentmaterials in the several conditions that may occur in operationof solar heating and cooling systems. These conditions include:(1) operating full flow; (2) stagnant empty vented; ( 3)stagnant, closed to atmosphere, non-draindown; and ( 4)stagnant, closed
6、to atmosphere, draindown.1.3 The recommended practices cover the following threetests:1.3.1 Practice ALaboratory Exposure Test for CouponSpecimens.1.3.2 Practice BLaboratory Exposure Test of Compo-nents or Subcomponents.1.3.3 Practice CField Exposure Test of Components orSubcomponents.1.4 Practice A
7、 provides a laboratory simulation of variousoperating conditions of solar heating and cooling systems. Itutilizes coupon test specimens and does not provide for heatingof the fluid by the containment material. Practice B provides alaboratory simulation of various operating conditions of a solarheati
8、ng and cooling system utilizing a component or a simu-lated subcomponent construction, and does provide for heatingof the fluid by the containment material. Practice C provides afield simulation of various operating conditions of solar heatingand cooling systems utilizing a component or a simulateds
9、ubcomponent construction. It utilizes controlled schedules ofoperation in a field test.1.5 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
10、and determine the applica-bility of regulatory limitations prior to use. For a specific safetyprecaution statement see Section 6.2. Referenced Documents2.1 ASTM Standards:E 712 Practice for Laboratory Screening of Metallic Con-tainment Materials for Use With Liquids in Solar Heatingand Cooling Syste
11、ms2G 1 Practice for Preparing, Cleaning, and Evaluating Cor-rosion Test Specimens33. Terminology3.1 Definitions:3.1.1 collector, na device designed to absorb incidentsolar radiation and transfer the energy to a heat-transfer fluid.A collector has an absorber surface, a containment membrane,and may o
12、r may not have insulation and glazing.3.1.2 panel, nthe absorber surface and containment mem-brane within the collector.3.1.3 component, nan individually distinguishable prod-uct that forms part of a more complex product, that is, asubsystem or system. The panel and collector are each com-ponents.3.
13、1.4 simulated subcomponent, na specimen fabricated insuch a manner as to embody the major characteristics of acomponent with regard to material selection, design, forming,joining, and surface condition.4. Significance and Use4.1 At this time none of these practices have been demon-strated to correla
14、te with field service.4.2 Because these procedures do not restrict the selection ofeither the containment material or the fluid for testing, it is1These test methods are under the jurisdiction of ASTM Committee E44 onSolar, Geothermal, and Other Alternative Energy Sources and is the directresponsibi
15、lity of Subcommittee E44.05 on Solar Heating and Cooling Subsystemsand Systems.Current edition approved May 30, 1980. Published August 1980. Origianllyapproved in 1980. Last previous edition approved in 1996 as E 74580(1996).2Annual Book of ASTM Standards, Vol 12.02.3Annual Book of ASTM Standards, V
16、ol 03.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.essential that consideration be given to the appropriate pairingof metal and fluid. Likewise, knowledge of the corrosionprotection mechanism and the probable mode of failure of
17、 aparticular metal is helpful in the selection of test conditions andthe observation, interpretation, and reporting of test results.4.3 It is important that consideration be given to each of thepermitted variables in test procedure so that the results will bemeaningfully related to field performance
18、. It is especiallyimportant that the time of testing selected be adequate tocorrectly measure the rate of corrosion of the containmentmaterial.NOTE 1Corrosion, whether general or localized, is a time-dependentphenomenon. This time dependence can show substantial nonlinearity. Forexample, formation o
19、f a protective oxide will diminish corrosion withtime, while certain forms of localized attack accelerate corrosion withtime. The minimum time required for a test to provide a corrosion rate thatcan be extrapolated for the prediction of long-term performance varieswidely, depending on the selection
20、of metal and fluid, and on the form ofcorrosion attack. Therefore, it is not possible to establish a singleminimum length of test applicable to all materials and conditions.However, it is recommended that for the tests described in these practices,a test period of no less than 6 months be used. Furt
21、hermore, it isrecommended that the effect of time of testing be evaluated to detect anysignificant time dependence of corrosion attack.4.4 It is essential for the meaningful application of theseprocedures that the length of test be adequate to detect changesin the nature of the fluid that might sign
22、ificantly alter thecorrosivity of the fluid. For example, exhaustion of chemicalinhibitor or chemical breakdown of the fluid may occur afterperiods of months in selected cycles of operation.NOTE 2Many fluids that may be considered for solar applicationscontain additives to minimize the corrosivity o
23、f 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 involving fl
24、uids with suchadditives, consideration must be given to the ratio of metal surface area tofluid volume as it may relate to an operating system.5. Materials5.1 Any metallic material may be selected for evaluation.The material must be capable of being described with sufficientaccuracy to permit reprod
25、uction of the test.5.2 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 being described chemically, as to
26、 its basic compo-nents and as to the presence or absence of minor componentsthat affect the interaction with the metal. It is permitted toprecondition the fluid before testing. Any such preconditioningtreatment shall be described in the report.6. Safety Precautions6.1 Particular attention must be di
27、rected 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 of all t
28、est personnel.7. Calculations and Interpretation of Results7.1 Determine the deterioration of the containment materialby measurement of weight loss when possible, by measure-ment of metal thinning, and by examination at 103 magnifi-cation for incidence of localized attack.7.1.1 Whatever cleaning met
29、hod is used, the possibility ofremoval of solid metal is present; this results in error in thedetermination of the corrosion rate. One or more cleaned andexamined specimens should be recleaned by the same methodand re-examined. Loss due to this second cleaning may be usedas a correction to the first
30、 one.7.1.2 To determine the corrosion rates based on weight loss,calculate the total surface area (making allowance for thechange in surface area due to mounting holes) and divide theweight loss by the area to obtain the weight loss per unit area.This result may be divided by the duration of the tes
31、t to obtainthe corrosion rate in weight loss per unit area per unit time(such as mg/dm2day = mdd). This result may be divided by thedensity of the metal to obtain a rate of loss in terms of thicknessof the specimen (mils per year = mpy), for instance:Rmdd5 100 000 Wo2 Wt!/AT! (1)where:Rmdd= the corr
32、osion rate, mdd,Wo= original weight, g,Wt= final weight, g,A = area, cm2, andT = duration, days.orRmpy5 393.7 Wo2 Wt/ATD! (2)where:Rmpy= corrosion rate, mpy,Wo= original weight, g,Wt= final weight, g,A = area, cm2,T = duration, years, andD = density, g/cm3.7.1.3 Identify any incidence of localized c
33、orrosion, whetherpitting, crevice attack, intergranular attack, cracking, or anyother form of localized attack, rate under at least 103magnification, and report. Report the location, distribution, andmaximum depth of attack for any localized attack.7.2 Report any changes of the heat-transfer fluid,
34、for ex-ample, appearance or odor, and include the results. Describeany changes in the appearance or condition of the testapparatus indicative of interaction with the metal specimen orfluid.7.3 In the event of film formation and buildup, report thenature of the film and its degree of buildup.7.4 For
35、the evaluation of a containment material couple, aneffort should be made to utilize the same procedures as for asingle material test. However, because of the variability per-mitted in the design of the specimen for the couple, it may notbe appropriate to report weight loss or penetration. For all te
36、stsof metal couple/fluid performance, special attention should beE 745 80 (2003)2given to observation and reporting of localized corrosion andevidence of galvanic attack.8. Report8.1 Identify the containment material using a recognizedstandard test method, where applicable, or by chemical analy-sis.
37、 In case of identification by a standard method, supplemen-tal identification by typical analysis for that standard, or bychemical analysis of the specimen is desirable.8.2 Report the dimensions and configuration of the speci-men. In the case of a metal couple, the report shall include atleast the f
38、ollowing elements: (1) description of the individualcomponents of the couple; (2) description of the method ofattachment or association of the couple including any thirdmaterial introduced as a binder or for other function and theprocedures or connection, for example, surface preparation,conditions
39、of attachment, and cleaning; (3) any change of thecontainment materials resulting from the coupling procedure;and (4) description of the relative areas of exposure of thecomponents of the couple to the heat-transfer medium.8.3 The heat-transfer fluid shall be identified by standardmethods where appl
40、icable, by initial chemical analysis, or byproprietary designation. Use of trademarks, or names ofpatented or proprietary products, without accompanyingchemical description is discouraged but not prohibited. Foraqueous transfer fluids, the analysis of the water used shall bereported.8.4 Identify the
41、 procedure used. Specify the test conditionsused, including specimen preparation, time and temperatureschedule, degree of atmospheric exposure of the heat transferfluid, stirring, and flow rate, where applicable. Describe themethod of temperature measurement and control, with com-ment on its accurac
42、y and precision. Report any deviation fromthe standard procedure and so identify as a deviation.8.5 Report the weight loss and average penetration rate,when applicable. If the time dependence of the corrosion rateis significant, (see Note 1), note this in the report, and includea plot of the corrosi
43、on rate as a function of time. Report allinstances of localized deterioration of the test specimen. In theevent of pitting or other non-uniform attack, report the fre-quency of attack and maximum penetration.8.6 A commentary on the results and their interpretation,particularly their applicability to
44、 various designs for solarheating and cooling systems, is optional but desirable.PRACTICE A LABORATORY EXPOSURE TESTFOR COUPON SPECIMENS9. Scope9.1 This procedure is intended to evaluate the resistance todeterioration of metallic containment materials in contact withvarious heat-transfer fluids. By
45、proper selection of test condi-tions, a wide range of operating conditions may be evaluated.However, the test procedure does not provide for a conditionwherein heat is transferred from the containment material intothe fluid.10. Test Specimens and Sample10.1 Select the test specimens from material th
46、at mayreasonably represent that material as it would be applied in asolar heating and cooling system.10.2 For laboratory corrosion tests that simulate exposure toservice environments, a commercial surface such as a millfinish, closely resembling the one that would be used inservice, will yield the m
47、ost 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 roughness terms, such as rmsin.10.3 General Cleaning:10.3.1 General cleaning may be accomplished with a widevar
48、iety of cleaning media. Water-based cleaners should befollowed by an alcohol dip after thorough rinsing. Solventcleaners such as petroleum fractions, aromatic hydrocarbons,and chlorinated hydrocarbons are generally acceptable. Chlo-rinated solvents, however, should not be used on titanium,staininles
49、s steel, or aluminum. Mechanical cleaning of verysmooth surfaces may be accomplished by using a pase ofmagnesium oxide or aluminum oxide.10.3.2 Any of the methods suitable for cleaning a givencorroded specimen may be used to complete the cleaning ofspecimens prior to test, provided that they do not causelocalized attack. The cleaned specimens should be measuredand weighted. Dimensions determined to the third significantfigure and weight determined to the fifth significant figure areusually satisfactory.10.4 Metallurgical ConditionSpecimen preparation maychange the metallur
