1、Designation: C 1617 05Standard Practice forQuantitative Accelerated Laboratory Evaluation ofExtraction Solutions Containing Ions Leached from ThermalInsulation on Aqueous Corrosion of Metals1This standard is issued under the fixed designation C 1617; the number immediately following the designation
2、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 This practice covers procedures for a
3、 quantitative accel-erated laboratory evaluation of the influence of extractionsolutions containing ions leached from thermal insulation onthe aqueous corrosion of metals. The primary intent of thepractice is for use with thermal insulation and associatedmaterials that contribute to, or alternativel
4、y inhibit, the aqueouscorrosion of different types and grades of metals due to solubleions that are leached by water from within the insulation. Thequantitative evaluation criteria are Mass Loss Corrosion Rate(MLCR) determined from the weight loss due to corrosion ofexposed metal coupons after they
5、are cleaned.1.2 The insulation extraction solutions prepared for use inthe test can be altered by the addition of corrosive ions to thesolutions to simulate contamination from an external source.Ions expected to provide corrosion inhibition can be added toinvestigate their inhibitory effect.1.3 Prep
6、ared laboratory standard solutions are used asreference solutions and controls, to provide a means ofcalibration and comparison. See Fig. 1.1.4 Other liquids can be tested for their potential corrosive-ness including cooling tower water, boiler feed, and chemicalstocks. Added chemical inhibitors or
7、protective coatings ap-plied to the metal can also be evaluated using the generalguidelines of the practice.1.5 This practice cannot cover all possible field conditionsthat contribute to aqueous corrosion. The intent is to provide anaccelerated means to obtain a non-subjective numeric value forjudgi
8、ng the potential contribution to the corrosion of metalsthat can come from ions contained in thermal insulationmaterials or other experimental solutions. The calculatednumeric value is the mass loss corrosion rate. This calculationis based on general corrosion spread equally over the testduration an
9、d the exposed area of the experimental cells createdfor the test. Corrosion found in field situations and thisaccelerated test also involves pitting and edge effects and therate changes over time.1.6 The measurement values stated in inch-pound units areto be regarded as standard.1.7 This standard do
10、es 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. Referenced Documents2.1 ASTM Sta
11、ndards:2A 53/A 53M Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and SeamlessA 105 Specification for Carbon Steel Forgings for PipingApplicationsC 518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC 665 Specification f
12、or Mineral-Fiber Blanket Thermal In-sulation for Light Frame Construction and ManufacturedHousingC 692 Test Method for Evaluating the Influence of ThermalInsulations on External Stress Corrosion Cracking Ten-dency of Austenitic Stainless SteelC 739 Specification for Cellulosic Fiber Loose-Fill Therm
13、alInsulationC 795 Specification for Thermal Insulation for Use in Con-tact with Austenitic Stainless SteelC 871 Test Methods for Chemical Analysis of ThermalInsulation Materials for Leachable Chloride, Fluoride,Silicate, and Sodium IonsG1 Practice for Preparing, Cleaning and Evaluating Corro-sion Te
14、st SpecimensG16 Guide forApplying Statistics toAnalysis of CorrosionDataG31 Practice for Laboratory Immersion Corrosion Testingof MetalsG46 Guide for Examination and Evaluation of PittingCorrosion1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct re
15、sponsibility of Subcommittee C16.31 on Chemical andPhysical Properties.Current edition approved May 1, 2005. Published June 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informati
16、on, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Summary of Practice3.1 The practice uses controlled amounts of test solutionsdelivered drip wise onto a defined ar
17、ea of small flat coupons ofselected test metals for the purpose of producing, comparing,and measuring the corrosion that occurs on the metals due tothe exposure. Preparation of the coupons includes sanding toremove oxidation and contamination and making the surfaceuniform and reproducible.3.2 The te
18、st is conducted at elevated temperatures, greatlyaccelerating the corrosion in comparison with corrosion atroom temperature. The heat makes the solution evaporatequickly, allowing an air (oxygen) interface and making thou-sands of wet-dry-wet cycles possible in a short time.3.3 Quantitative measurem
19、ents of corrosion are determinedfrom the weight change (loss) due to the corrosion of the testedcoupons. Reference tests prepared with known concentrationsof solutions that are conducive to the corrosion of the testedmetal are compared with water solutions containing ionsextracted from insulation sa
20、mples. Calculations of MLCR inmils-per-year (MPY) made using the methods of Practice G1are reported as the quantitative measurement.4. Significance and Use4.1 Corrosion associated with insulation is an importantconcern for insulation manufacturers, specification writers,designers, contractors, and o
21、perators of the equipment. SomeNOTE 1The Fig. 1 bar graph was created using the MLCR data shown in Table 1. Standard reference tests using de-ionized water, 1 ppm, 5 ppm,and 10 ppm chloride solutions were performed on mild carbon steel coupons. The calculated MLCR test results for mild carbon steel
22、coupons wereseparated into four ranges. The rating criteria ranges were developed to accommodate the results obtained using this practice on the reference standardsand experimental insulation samples. The ranges used are: MLCR=0to15mils = range A; MLCR = 15.1 to 35 mils = range B; MLCR = 35.1 to 60m
23、ils = range C, MLCR = 60.1 and higher = range D. The bars on the graph represent the total number of occurrences within the range for each of thereference solutions.NOTE 2It is necessary for each laboratory to develop their own data, with their own individual plate or plates, metal, operators, clean
24、ing procedures,and environmental conditions to establish the ranges of MLCR calculated for the reference standards. The insulation or other test solutions are thenevaluated against the reference solution results.FIG. 1 Standard Reference TestsC1617052material specifications contain test methods (or
25、reference testmethods contained in other material specifications), for use inevaluating the insulation with regard to the corrosion of steel,copper, and aluminum. In some cases these tests are notapplicable or effective and have not been evaluated for preci-sion and bias.4.2 Aproperly selected, inst
26、alled, and maintained insulationsystem will reduce the corrosion that often occurs on anun-insulated structure. However, when the protective weather-resistant covering of an insulation system fails, the conditionsfor the aqueous environment necessary for corrosion underinsulation (CUI) often develop
27、. It is possible the insulationcontains, collects, or concentrates corrosive agents, or a com-bination thereof, often found in industrial and coastal environ-ments. If water is not present, these electrolytes cannot migrateto the metal surface. The electrochemical reaction resulting inthe aqueous co
28、rrosion of metal surfaces cannot take place inthe absence of water and electrolytes. Additional environmen-tal factors contributing to increased corrosion rates are oxygen,and elevated-temperature (near boiling point).4.3 Chlorides and other corrosive ions are common to manyenvironments. The primary
29、 corrosion preventative is to protectinsulation and metal from contamination and moisture. Insu-lation covers, jackets, and metal coating of various kinds areoften used to prevent water infiltration and contact with themetal.4.4 This procedure can be used to evaluate all types ofthermal insulation a
30、nd fireproofing materials (industrial, com-mercial, residential, cryogenic, fire-resistive, insulating ce-ment) manufactured using inorganic or organic materials.4.5 This procedure can be used with all metal types forwhich a coupon can be prepared such as mild steel, stainlesssteel, copper, or alumi
31、num.4.6 This procedure can also be applicable to insulationaccessories including jacketing, covers, adhesives, cements,and binders associated with insulation and insulation products.4.7 Heat treatment of the insulation (as recommended by themanufacturer up to the maximum potential exposure tempera-t
32、ure) can be used to simulate possible conditions of use.4.8 Adhesives can be tested by first drying followed bywater extraction or by applying a known quantity of the testadhesive to a test piece of insulation and then extracting.4.9 Insulating cements can be tested by casting a slab,drying, and ext
33、racting or by using the uncured insulatingcement powder for extraction.4.10 Reference tests prepared with various concentrationsof solutions that are conducive to the corrosion of the testedmetal serve as comparative standards. Solutions containingchloride, sodium hydroxide, various acids (sulfuric,
34、 hydrochlo-ric, nitric, and citric acid), as well as “blank” tests using onlyde-ionized water and tap water are used.4.11 Research can be done on insulation that has beenspecially formulated to inhibit corrosion in the presence ofcorrosive ions through modifications in basic composition orincorporat
35、ion of certain chemical additives. Corrosive ions canalso be added to the insulation extraction solutions to deter-mine the effectiveness of any inhibitors present.4.12 Protective surface treatments and coatings of differenttypes and thickness can be applied to the metal coupons andcompared using va
36、rious corrosive liquids.4.13 Several sets of tests are recommended because of thenumber of factors that affect corrosion. An average of the testsand the standard deviation between the test results are used onthe data. Much of the corrosion literature recommends aminimum of three specimens for every
37、test. Consult GuideG16for additional statistical methods to apply to the corrosiondata.4.14 Results from this accelerated corrosion test shall not beconsidered as an indicator of the useful life of the metalequipment. Many factors need consideration for applicabilityto specific circumstances. Refer
38、to Practice G31for additionalinformation.5. Apparatus5.1 The test apparatus must be housed in a reasonably cleanand non-dusty environment to avoid any effects of contami-nants.5.2 Electrically Heated Thermostatically Controlled FlatHot Plate (see Appendix X1)A 1-ft (30.5-cm) square orcircular plate
39、that has uniform temperature across the surfaceprovides the heated environment. See Appendix X1 for con-struct design and sources of assembled systems.5.3 Peristaltic Pump (see Appendix X1)A multi-channelperistaltic pump with individual cassettes and silicone tubes isrecommended to supply 250 (625)
40、mL/day to each specimen.5.4 Silicone Rubber Tubing (see Appendix X1), to deliverfluid to the test coupons.5.5 Miniature Barbed Fitting (see Appendix X1), for con-nections of tubing (116 by116 in.).5.6 Band Saw.5.7 Balance, capable of 0.0001 (60.0002) g mass determi-nation.5.8 Wet-Grinding Belt Grind
41、er/Sander, with used 80-grit (abelt previously used to make Test Method C 692 stainless steelcoupons is acceptable) or new 120-grit wet belt.5.9 Drying Oven.5.10 Bottles, plastic 1 Lor equivalent, to individually supplyeach test specimen with test liquid.5.11 Nominal 1-in. Thin-wall PVC Pipe,1516-in
42、. OD; 1316-in. ID by 2-in. lengths.5.12 High Temperature Grease, Never-Seez or equivalentfor use as heat transfer grease.5.13 Rubber O-Ring,114-in. ID, 112-in. OD,18-in. thick.5.14 Silicone Sealant, GE Silicone II or equivalent.5.15 Plastic Straw,18-in. drink stirring straw (“swizzlestick”) cut to 1
43、-in. length.5.16 Cleaning Apparatus and Solutions, for the coupons,stainless steel metal scourer pad, 3-M sanding pad (mediumand fine) or equivalent sand paper, acetone, xylene, water,paper towels.5.17 Hand-Held Magnifier,or10to303 binocular micro-scope, or both.6. Reagents and Materials6.1 Distille
44、d or De-Ionized Water, containing less than 0.1ppm chloride ions.C16170536.2 Metal Test Coupons, meeting the composition require-ments of applicable ASTM Specification for Mild Steel,Stainless Steel, Copper, or Aluminum. Mill certificates ofchemical composition and mechanical properties are required
45、.The gage of the metal shall be 16 to 22-gage depending on typeof metal and availability.6.2.1 Some researchers will want to maintain traceability tothe metals used in other C16 corrosion procedures. Specifica-tion C 739 uses cold rolled, low carbon (0.30 %) commercialquality shim steel. Specificati
46、on C 665 uses cold rolled, lowcarbon, quarter hard, temper No. 3, strip steel. It is possibleother metal grades meeting Specification A 53/A 53M, Speci-fication A 105, and other common ferrous steel specificationsare of interest for use in the tests. If stainless steel coupons areto be used, it is r
47、ecommended that they be 16-gage andprepared following the sensitization procedure described inTest Method C 692 Section 9 on Test Coupons (sensitizestainless steel coupons by heating at 1200F (649C) in anargon (inert) or air (oxidizing) atmosphere for three hours).Galvanized steel is not suitable fo
48、r test because the elevatedtemperatures recommended by the practice are above therecommended use temperature of galvanized metal. However,with suitable adjustments to slow the drip rate and lower thetemperature of the hot plate, there are possibilities for thedevelopment of test practices.6.2.2 It i
49、s likely that different results will be found whenswitching between various metal grades. The use of standardsolutions of corrosive ions provides a benchmark against whichthe leachable ions contained in the insulation are evaluated.The standard solutions are run during every test sequence, afterhaving previously established the range of results for theindividual laboratory and the type, grade, and lot of metal.6.3 Chemically Pure Salts and Reagent Grade Acids shallbe used for preparation of corrosion solutions used as referencestandards for plate calibration and compariso
