EN ISO 22088-6-2009 en Plastics - Determination of resistance to environmental stress cracking (ESC) - Part 6 Slow strain rate method《塑料 耐环境应力开裂(ESC)能力的测定 第6部分 慢应变速率法》.pdf

1、BS EN ISO22088-6:2009ICS 83.080.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPlastics Determinationof resistance toenvironmental stresscracking (ESC)Part 6: Slow strain rate method (ISO22088-6:2006)This British Standardwas published under theauthority of th

2、e StandardsPolicy and StrategyCommittee on 31 August2009 BSI 2009ISBN 978 0 580 57123 7Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 22088-6:2009National forewordThis British Standard is the UK implementation of EN ISO22088-6:2009. It is identical to ISO 22088-6:2006.The UK pa

3、rticipation in its preparation was entrusted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsibl

4、e for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 22088-6June 2009ICS 83.080.01English VersionPlastics - Determination of resistance to environmental stresscracking (ESC) - Part 6: Slow

5、strain rate method (ISO 22088-6:2006)Plastiques - Dtermination de la fissuration sous contraintedans un environnement donn (ESC) - Partie 6: Mthode vitesse de dformation lente (ISO 22088-6:2006)Kunststoffe - Bestimmung der Bestndigkeit gegenumgebungsbedingte Spannungsrissbildung (ESC) - Teil 6:Verfa

6、hren mit langsamer Dehnrate (ISO 22088-6:2006)This European Standard was approved by CEN on 23 May 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration.

7、Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationun

8、der the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, H

9、ungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre:

10、 Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 22088-6:2009: EBS EN ISO 22088-6:2009EN ISO 22088-6:2009 (E) 3 Foreword The text of ISO 22088-6:2006 has been prepared by Technical Committee

11、 ISO/TC 61 “Plastics” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 22088-6:2009 by Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by pu

12、blication of an identical text or by endorsement, at the latest by December 2009, and conflicting national standards shall be withdrawn at the latest by December 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CEN

13、ELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denm

14、ark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 22088-6:2006 has been appr

15、oved by CEN as a EN ISO 22088-6:2009 without any modification. BS EN ISO 22088-6:2009ISO 22088-6:2006(E) ISO 2006 All rights reserved iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 3 5 Apparatus 4 6 Conditioning and test conditions 5 6.1 C

16、onditioning 5 6.2 Test temperature. 5 6.3 Test medium 5 7 Test specimens . 5 8 Procedure 5 9 Expression of results . 6 10 Test report . 7 Annex A (normative) Strain calculation from crosshead displacement. 8 Bibliography . 9 BS EN ISO 22088-6:2009ISO 22088-6:2006(E) iv ISO 2006 All rights reservedFo

17、reword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a tec

18、hnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o

19、f electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated

20、to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible fo

21、r identifying any or all such patent rights. ISO 22088-6 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 6, Ageing, chemical and environmental resistance. ISO 22088 consists of the following parts, under the general title Plastics Determination of resistance to environmental

22、 stress cracking (ESC): Part 1: General guidance Part 2: Constant tensile load method (replacement of ISO 6252:1992) Part 3: Bent strip method (replacement of ISO 4599:1986) Part 4: Ball or pin impression method (replacement of ISO 4600:1992) Part 5: Constant tensile deformation method (new test met

23、hod) Part 6: Slow strain rate method (new test method) BS EN ISO 22088-6:2009INTERNATIONAL STANDARD ISO 22088-6:2006(E) ISO 2006 All rights reserved 1Plastics Determination of resistance to environmental stress cracking (ESC) Part 6: Slow strain rate method 1 Scope This part of ISO 22088 describes a

24、 procedure for assessing the environmental stress cracking (ESC) susceptibility of polymeric materials in chemical environments by slowly increasing the strain applied to a tensile specimen at a constant rate. It is applicable to test specimens prepared by moulding and/or machining and can be used t

25、o assess the relative ESC susceptibility of a material exposed to different environments or the relative ESC susceptibility of different plastics exposed to a specific environment. This is essentially a ranking test and is not intended for the provision of design data. The principle advantage of the

26、 test compared with the test methods described in Parts 2 to 5 of ISO 22088 is the rapidity with which the ESC susceptibility of a particular polymer/environment combination can be assessed. 2 Normative references The following referenced documents are indispensable for the application of this docum

27、ent. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 527-2, Plastics Determination of tensile properties Part 2: Test conditions for moulding and extrusion plastics ISO 22088-1, Plasti

28、cs Determination of resistance to environmental stress cracking (ESC) Part 1: General guidance 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 22088-1 and the following apply. 3.1 crosshead displacement CHD distance the crosshead has moved from the s

29、tart of the test 3.2 crosshead speed CHS distance travelled by the crosshead, CHD, divided by the time from the start of the test BS EN ISO 22088-6:2009ISO 22088-6:2006(E) 2 ISO 2006 All rights reserved3.3 length of parallel-sided section of specimen l1length of the narrow parallel-sided section in

30、the middle of the specimen (see Figure 1) 3.4 area of parallel-sided section A1cross-sectional area of the narrow parallel-sided section of the specimen (see Figure 1) 3.5 length of tapered region l2overall length of the tapered/non-parallel-sided region at one end of the specimen (see Figure 1) 3.6

31、 length increment l2length of the sections into which the tapered/non-parallel-sided regions are divided in order to calculate the effective gauge length (see Figure 1) 3.7 area of incremental section in tapered section A2average cross-sectional area of one of the incremental sections into which the

32、 tapered/non-parallel-sided regions of the specimen are divided (see Figure 1) aNarrow parallel-sided section of the specimen, of length l1and cross-sectional area A1. bTapered/non-parallel-sided region of the specimen, of length l2. cIncremental sections (of no more than 1 mm in length) into which

33、the tapered region is divided, of length l2and cross-sectional area A2. Figure 1 Schematic diagram of the specimen showing the relevant dimensions 3.8 effective gauge length l0length of the specimen under strain, taking into account the contributions made by both the narrow parallel-sided section an

34、d the tapered sections at each end of the specimen NOTE The grips are assumed to extend up to the beginning of the tapered region of the specimen. If gripped further back, allowance for the displacement in the wider parallel-sided section of the specimen will have to be made. The effective gauge len

35、gth is given by: 201 122lllAA=+BS EN ISO 22088-6:2009ISO 22088-6:2006(E) ISO 2006 All rights reserved 33.9 stress force measured by the load cell divided by the initial cross-sectional area, A13.10 strain distance, d, the crosshead has moved during the test, divided by the effective gauge length, l0

36、(see Annex A) 3.11 strain rate strain, , in the specimen divided by the time from the start of the test 4 Principle The test involves subjecting a specimen to an increasing strain at a constant crosshead displacement rate while it is exposed to a specified test medium. The tests are conducted under

37、tension at relatively low strain rates to enhance the influence of the test medium on the specimen. The development of crazes causes the strain to be taken up locally at the crazes such that the stress is reduced compared to an inert environment. The focus of the test is to identify craze initiation

38、, which is associated with the departure of the stress-strain curve in the test medium from that in air (see Figure 2). The departure stress or departure strain tends to be a very repeatable and reproducible parameter but the time to failure, if indeed the specimen fails within the range of displace

39、ment of the machine, can be highly variable and does not provide a useful basis for ranking the performance of plastics exposed to different fluids. Key X strain Y stress (MPa) 1 specimen tested in air 2 specimen tested in test medium 3 departure point Figure 2 Typical stress-strain plot showing dif

40、ference in stress-strain profile for material exposed in air and in the test medium BS EN ISO 22088-6:2009ISO 22088-6:2006(E) 4 ISO 2006 All rights reservedThe definition of departure depends on the perspective by which the stress-strain curves are viewed and the “noise” level of the parameters. To

41、avoid subjective judgement, and based on extensive measurements of a wide range of plastic-fluid pairs1 to 4, departure has been defined as occurring when the derivative of the stress-strain curve (see 9.3) obtained in the test medium falls to 75 % of the derivative of the curve obtained in air. Thi

42、s accounts better for those systems for which initial stiffening occurs due to environment exposure (see Figure 3). Key X strain Y tangent modulus (MPa) 1 specimen tested in air 2 specimen tested in test medium 3 departure point Figure 3 Typical plot showing the tangent modulus of the stress-strain

43、curves as a function of strain (departure is defined as the point at which the derivative of the curve obtained in the test medium falls to 75 % of the derivative of the curve obtained in air) 5 Apparatus 5.1 Tensile-testing machine, capable of producing a constant displacement rate, repeatable to 2

44、 %. The initial strain rate that has been used most frequently in the slow strain rate testing of plastics is 9 106s1. Care shall be taken to ensure that the apparatus subjects the specimens only to forces parallel to their longitudinal axis and not to bending or twisting forces. The load shall be m

45、easured using a load cell accurate to 1 % and crosshead displacement shall be measured using a displacement transducer accurate to 0,4 %. The load and displacement shall be recorded throughout the test, at intervals of not more than 10 min, using a data-logger. BS EN ISO 22088-6:2009ISO 22088-6:2006

46、(E) ISO 2006 All rights reserved 55.2 Grips with ripple contact, for gripping the specimens in such a way that no slippage occurs during the test. 5.3 The specimen and grips are enclosed in a test chamber which shall be inert to the extent that it has no influence on the test fluid and hence the res

47、ults. 6 Conditioning and test conditions 6.1 Conditioning Unless otherwise agreed by the interested parties, the specimens shall be stored under controlled conditions for at least 24 h at (23 2) C and (50 10) % relative humidity. 6.2 Test temperature Unless otherwise agreed by the interested parties

48、, the temperature shall be maintained at (23 2) C. 6.3 Test medium The test medium used shall represent that used in service or be prepared from analytical reagent grade chemicals. 7 Test specimens 7.1 Test specimens shall be produced using the dimensions quoted for the type 1BA tensile specimens in

49、 ISO 527-2, unless there are specific reasons for doing otherwise. 7.2 Unless otherwise agreed by the interested parties, the machined edges of the specimen shall be dry-ground progressively using 400 grit, 600 grit, 800 grit and 1 200 grit abrasive papers. 7.3 Prior to testing, the specimens shall be cleaned in an ultrasonic bath with distilled water for 1 min and then gently dried with a tissue. 7.4 Specimens shall be visually inspected for evidence of damage before they are used.