ASTM D5485-2009 Standard Test Method for Determining the Corrosive Effect of Combustion Products Using the Cone Corrosimeter.pdf

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1、Designation: D 5485 09An American National StandardStandard Test Method forDetermining the Corrosive Effect of Combustion ProductsUsing the Cone Corrosimeter1This standard is issued under the fixed designation D 5485; the number immediately following the designation indicates the year oforiginal ado

2、ption 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.1. Scope*1.1 This fire-test-response standard measures the corrosiveeffect by loss

3、of metal from the combustion products ofmaterials, components, or products.1.2 This test method provides corrosion results of productand material specimens limited to a maximum size of 100 by100 mm in area and 50 mm thick.1.3 The results of this test method have not been investi-gated with respect t

4、o correlation to actual fires.1.4 This standard measures and describes the response ofmaterials, products, or assemblies to heat and flame undercontrolled conditions, but does not by itself incorporate allfactors required for fire hazard or fire risk assessment of thematerials, products, or assembli

5、es under actual fire conditions.1.4.1 Additional information regarding the targets, the testconditions, and test limitations are provided in the annex.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

6、 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 7.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thissta

7、ndard. (See IEEE/ASTM SI-10)2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 1711 Terminology Relating to Electrical InsulationD6113 Test Method for Using a Cone Calorimeter toDetermine Fire-Test-Response Characteristics of Insulat-ing Materials Contai

8、ned in Electrical or Optical FiberCablesE 176 Terminology of Fire StandardsE 1354 Test Method for Heat and Visible Smoke ReleaseRates for Materials and Products Using an Oxygen Con-sumption CalorimeterIEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System

9、2.2 Other Document:OSHA 191.1450 Occupational Exposure to Hazard Chemi-cals in Laboratories33. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminologies E 176 and D 1711.3.2 Definitions of Terms Specific to This Standard:3.2.1 cone corrosimeter, nequip

10、ment used to determinecorrosion in this test method.3.2.2 corrosion-by-metal-loss, nloss of metal of a targetexpressed as reduction of thickness of the target metal.3.2.3 exposure chamber, nenclosure in which a target isexposed to combustion products.3.2.4 heating flux, nincident power per unit area

11、 that isimposed externally from the heater on the specimen.3.2.4.1 DiscussionThe specimen, once ignited, is alsoheated by its own flame.3.2.5 sustained flaming, nexistence of flame on or overthe surface of the test specimen for periods of4sormore.3.2.5.1 DiscussionFlaming ignition of less than4sisid

12、entified as transitory flaming or flashing.3.2.6 target, ndetector of known electrical resistancewhich can lose metal through a process of corrosion when it isexposed to combustion products.3.3 Symbols Specific to This Standard:3.3.1 A0initial corrosion instrument reading.3.3.2 A1corrosion instrumen

13、t reading at the end of 1-hexposure to combustion products.3.3.3 A24corrosion instrument reading at the end of 24 hin the environmental chamber.3.3.4 Ccorrosion of a target, nm.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is t

14、he direct responsibility ofSubcommittee D09.21 on Fire Performance Standards.Current edition approved June 1, 2009. Published July 2009. Originally approvedin 1994. Last previous edition approved in 2005 as D 5485 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AST

15、M Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Occupational Safety and Health Administration (OSHA)/U.S.Departmnet of Labor, 200 Constitution Ave., NW, Washington, DC 20210, h

16、ttp:/www.osha.gov.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3.5 C1corrosion at the end of 1-h exposure to combus-tion products, nm.3.3.6 C24corrosion at the en

17、d of 24 h in the environmentalchamber, nm.3.3.7 mspecimen mass, g.3.3.8 mffinal specimen mass, g.3.3.9 miinitial specimen mass, g.3.3.10 m70average 70 % of the total mass loss, g.3.3.11 tdsampling time, s.3.3.12 Tetemperature of the gas in the exposure chamber,C.3.3.13 Vvolumetric sampling rate of c

18、ombustion prod-ucts, m3/s.4. Summary of Test Method4.1 In this test method, a specimen is subjected to radiantheat. A spark igniter is used to ignite the combustible vapors.The products of decomposition or combustion are channeledthrough a funnel. A portion of the products continuously flowsthrough

19、an exposure chamber which holds the corrosion targetsuntil the specimen has lost an average 70 % of the totalcombustible mass or for a period of 60 min, whichever is less.The corrosion of the target is determined by exposure of thetarget to combustion products for 1 h, followed by 24-hexposure of th

20、e target to a controlled humidity and temperatureenvironment in a separate chamber. The increase in electricalresistance of each target is monitored, and the reduction inthickness of the metal on the target is calculated from theincrease in electrical resistance. This reduction in thickness isreferr

21、ed to as corrosion-by-metal-loss.4.2 This test method involves the use of a cone corrosimeteras described in Section 7 and shown in Fig. 1.4.3 Alternate equipment found suitable for this test methodis the cone calorimeter (see Test Method E 1354), with theaddition of the gas sampling system describe

22、d in this testmethod.5. Significance and Use5.1 The metal loss from corrosion is directly related to theincrease in electrical resistance of the target due to the decreasein conductive cross-sectional area.5.2 The relationship between resistance increase of metallictargets used in this test method a

23、nd the amount of metal loss asreported by a uniform loss in thickness has not been deter-mined.5.3 This test method is used to determine the corrosiveeffect of combustion products from burning electrical insula-tions or coverings or their constituent materials or components.Corrosion is determined b

24、y the reduction of thickness of themetal on standardized targets, as measured by electrical resis-tance. These targets are not necessarily representative of theintended end use.5.4 This test method is intended for use in electricalinsulations or coverings material and product evaluations, foradditio

25、nal data to assist in design of electrical insulations orcoverings products, or for development and research of elec-trical insulations or coverings products.5.5 A value of the heating flux is selected to be relevant tothe fire scenario being investigated (up to 100 kW/m2).Additional information for

26、 testing is given in A1.2.3.6. Interferences6.1 Discard the test data if any of the following occur:FIG. 1 Cone CorrosimeterD54850926.1.1 Leakage occurs between the sampling point and theexit of the exposure chamber which could cause a dilution ofgases.6.1.2 The specimen swells sufficiently prior to

27、 ignition totouch the spark plug or swells into the plane of the heater baseplate during combustion.6.1.3 The specimen drips off the specimen holder or fallsout of the specimen holder such that the specimen is notsubjected to the test exposure conditions.6.1.4 There is highly localized corrosion of

28、the target,indicating a defective target.6.1.5 There is visual degradation of the reference circuit bythe attack of combustion products on or under the protectivecoating.7. Apparatus7.1 General:7.1.1 This test method uses the cone corrosimeter describedin 7.1.3. Alternatively, the cone calorimeter t

29、est equipment isacceptable provided that it is equipped with a gas samplingsystem as described in 7.8. If the cone calorimeter is used toassess the fire properties of insulating materials contained inelectrical or optical fiber cables, the test shall be conducted inaccordance with Test Method D6113,

30、 which was developedspecifically for that purpose.7.1.2 The dimensions of the cone corrosimeter specimenholder and additional equipment used in collection of gassamples are given in Figs. 1-11 and also stated in the followingdescription.7.1.3 The cone corrosimeter consists of the following maincompo

31、nents: conical-shaped radiant electric heater; tempera-ture controller; load cell; electric ignition spark plug; heat-fluxgage; exhaust system; specimen holder; and the gas samplingsystem. Other essential elements needed to measure corrosionare a corrosion target and a device to measure corrosion (s

32、ee7.9). A general view of the cone corrosimeter is shown in Fig.1.7.2 Conical Heater:7.2.1 The active element of the heater consists of anelectrical heater rod, rated at 5000 W at 240 V, tightly woundinto the shape of a truncated cone (Fig. 2). The heater isencased on the outside with a double-wall

33、stainless steel cone,and packed with a refractory fiber material of approximately100-kg/m3density.7.2.2 The heater is capable of producing heating flux on thesurface of the specimen of up to 100 kW/m2with a uniformityof 6 2 % within the central 50 by 50-mm area of the specimen.7.2.3 The heating flux

34、 from the heater is held at a presetlevel by means of a temperature controller and three Type Kstainless-steel-sheathed thermocouples having an outside di-ameter of 1.5 to 1.6 mm with an unexposed hot junction.Alternatively, either 3-mm outside diameter sheathed thermo-couples with an exposed hot ju

35、nction, or 1-mm outsidediameter sheathed thermocouples with an unexposed hot junc-tion are suitable. They are symmetrically disposed and incontact with, but not welded to, the heater element (see Fig. 2).The thermocouples are of equal length and wired in parallel tothe temperature controller.7.3 Tem

36、perature Controller:7.3.1 The temperature controller for the heater is to hold theelement temperature steady to within 6 2 C. A suitabletemperature controller system is a “3-term” controller (propor-tional, integral, and derivative) with a thyristor unit capable ofswitching currents up to 25 A at 24

37、0 V.7.3.2 The controller has a temperature input range from 0 to1000 C; a set scale with a resolution of 2 C; and automaticcold junction compensation. The controller is equipped with asafety feature such that in the event of an open circuit in thethermocouple line, it will cause the temperature to f

38、all to nearthe bottom of its range.7.3.3 The temperature controller uses a zero-crossing-typethyristor unit.7.3.4 The heater temperature is monitored by a meter with aresolution of 2 C.7.4 Exhaust System:FIG. 2 Cross-Section View Through the HeaterD54850937.4.1 The exhaust-gas system consists of a h

39、igh-temperaturecentrifugal exhaust blower, a hood, intake and exhaust ductsfor the fan, and an orifice plate flowmeter (Fig. 3).7.4.2 The flow rate is determined by measuring the differ-ential pressure across a sharp-edged orifice (57-mm insidediameter) in the exhaust stack, at least 350 mm downstre

40、amfrom the fan.7.4.3 In other details, the geometry of the exhaust system isnot critical. Where necessary, small deviations from the rec-ommended dimensions given in Fig. 3 are allowed. Forexample, it is permissible for the inner diameter of the duct andthe orifice plate to be slightly different (to

41、lerance: 6 2 mm).The location of the fan in Fig. 3 shall be between 900 and 1200mm downstream of the hood. Flow through the fan ensuresadequate mixing, which is essential to the test.7.5 Load CellThe general arrangement of the load cellwith the conical heater is shown in Fig. 4. Use a load cell with

42、an accuracy of 0.1 g, a measuring range of at least 500 g, anda mechanical tare adjustment range of 3.5 kg.7.6 Specimen Holder and Mounting:7.6.1 Two specimen holders are described, one in 7.6.2-7.6.4 and one in 7.6.5.7.6.2 The first specimen holder is shown in Fig. 5. Thebottom is constructed from

43、2.4-mm nominal stainless steel andhas outside dimensions of 106 by 106 by 25-mm height (6 2mm).7.6.2.1 Optionally, use an edge frame and a grid. Theoptional edge frame (Fig. 6) is constructed from 1.9-mmnominal stainless steel with outside dimensions of 111 by 111by 54-mm height (6 2 mm). The option

44、al grid (Fig. 7)isconstructed from 1-mm nominal stainless steel and has dimen-sions of 109 by 109 mm (6 2 mm). The optional grid has2-mm ribs and the openings in the center are 20 by 20 mm (6 1mm).7.6.3 The distance between the bottom surface of the coneheater and the top of the specimen shall be ad

45、justed to be 25 61mm(Fig. 2), except as indicated in 7.6.3.1.7.6.3.1 The distance between the bottom surface of the coneheater and the top of the specimen shall be adjusted to 60 mmin the case of those dimensionally unstable materials that havethe potential to intumesce or deform to such an extent t

46、hat theyare likely to make physical contact with either (a) the sparkplug before ignition or (b) the underside of the cone heater afterignition.FIG. 3 Exhaust SystemFIG. 4 Exploded View of Load Cell and Cone Radiant HeaterD54850947.6.3.2 If a test is conducted in accordance with the speci-men mounti

47、ng in 7.6.3.1 (a 60 mm distance), the heat fluxcalibration shall be performed with the heat flux meter posi-tioned 60 mm below the cone heater base plate.7.6.3.3 If a test has been conducted with a distance of 25mm and the type of physical contact described in 7.6.3.1 hasoccurred, that test shall be

48、 deemed invalid and the distanceshall be adjusted to 60 mm for future tests.7.6.4 Intumescent materials. The testing technique to beused when testing intumescing specimens in the horizontalorientation shall be documented in the test report. Optionsinclude those shown in 7.6.4.1-7.6.4.4.7.6.4.1 Use a

49、 retainer frame or edge frame (Fig. 6). Theedge frame is used to reduce unrepresentative edge burning ofspecimens. The edge frame is constructed from 1.9-mm nomi-nal stainless steel with outside dimensions of 111 by 111 by54-mm height (6 2 mm).7.6.4.2 Use a wire grid (Fig. 7). The wire grid is used forretaining specimens prone to delamination and is suitable forseveral types of intumescent specimens. The grid is con-structed from 1-mm nominal stainless steel and has dimensionsof 109 by 109 mm (62 mm). The grid has 2-mm ribs and theopenings in the center