1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58environmental stress cracking (ESC) Part 1: General guidanceThe European Standard EN ISO 22088-1:20
2、06 has the status of a British StandardICS 83.080.01Plastics Determination of resistance to BRITISH STANDARDBS EN ISO 22088-1:2006BS EN ISO 22088-1:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 BSI 2006ISBN 0 580 48766
3、 0Amendments issued since publicationAmd. No. Date Commentscontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. National forewordThis British Standard was published by BSI. It is the UK implementation of EN ISO
4、22088-1:2006.The UK participation in its preparation was entrusted to Technical Committee PRI/21, Testing of plastics.A list of organizations represented on PRI/21 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a EUROPEAN STAN
5、DARDNORME EUROPENNEEUROPISCHE NORMEN ISO 22088-1August 2006ICS 83.080.01English VersionPlastics - Determination of resistance to environmental stresscracking (ESC) - Part 1: General guidance (ISO 22088-1:2006)Plastiques - Dtermination de la fissuration sous contraintedans un environnement donn (ESC)
6、 - Partie 1: Lignesdirectrices gnrales (ISO 22088-1:2006)Kunststoffe - Bestimmung der Bestndigkeit gegenumgebungsbedingte Spannungsrissbildung (ESC) - Teil 1:Allgemeine Anleitung (ISO 22088-1:2006)This European Standard was approved by CEN on 21 July 2006.CEN members are bound to comply with the CEN
7、/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to an
8、y CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN m
9、embers are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerla
10、nd and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 2
11、2088-1:2006: EForeword This document (EN ISO 22088-1:2006) has been prepared by Technical Committee ISO/TC 61 “Plastics“ in collaboration with Technical Committee CEN/TC 249 “Plastics“, the secretariat of which is held by IBN. This European Standard shall be given the status of a national standard,
12、either by publication of an identical text or by endorsement, at the latest by February 2007, and conflicting national standards shall be withdrawn at the latest by February 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are b
13、ound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerla
14、nd and United Kingdom. Endorsement notice The text of ISO 22088-1:2006 has been approved by CEN as EN ISO 22088-1:2006 without any modifications. EN ISO 22088-1:2006Reference numberISO 22088-1:2006(E)INTERNATIONAL STANDARD ISO22088-1First edition2006-08-15Plastics Determination of resistance to envi
15、ronmental stress cracking (ESC) Part 1: General guidance Plastiques Dtermination de la fissuration sous contrainte dans un environnement donn (ESC) Partie 1: Lignes directrices gnrales EN ISO 22088-1:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms an
16、d definitions. 2 4 Principles of the test. 2 5 Applicability of the test method 3 6 Test specimen preparation 3 7 Conditioning and test conditions 3 7.1 Conditioning 3 7.2 Test temperature. 3 7.3 Test medium 4 Annex A (informative) Examples of test methods for various plastics 5 Bibliography . 6 EN
17、ISO 22088-1:2006iv Foreword 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 su
18、bject for which a technical 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 (
19、IEC) on all matters of 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 commi
20、ttees are circulated 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 b
21、e held responsible for identifying any or all such patent rights. ISO 22088-1 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 resist
22、ance to environmental 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
23、 method (new test method) Part 6: Slow strain rate method (new test method) EN ISO 22088-1:2006vIntroduction When a plastic material is stressed or strained in air below its yield point, stress cracking can occur after a period of time, which may be very long. These stresses may be internal or exter
24、nal, or a combination of both. Simultaneous exposure to a chemical environment and stress or strain may result in a dramatic shortening of the time to failure compared to that in an inert environment. The phenomenon is referred to as environmental stress cracking (ESC) and is exhibited by many mater
25、ials, including plastics. The permissible long-term stress or strain may be reduced considerably by this phenomenon. It is generally believed that ESC occurs via the following processes: 1) Formation of microvoids in specimens by microscopic stress concentrations after applying stress. 2) Formation
26、and subsequent growth of macrovoids caused by the breakdown of intermolecular bonds in intervoids that is produced by the action of a chemical environment, and formation of crazes which are composed of interconnected voids and fibrils. 3) Growth of the crazes caused by the break-down of the fibrils
27、due to the applied stress and contact with a chemical environment. 4) Finally, a crack starts at the tip of the craze, leading to brittle failure. The cracks may penetrate completely through the thickness of the material, separating it into two or more pieces, or they may be arrested on reaching reg
28、ions of lower stress or different material morphology. The determination of ESC is complex because it is influenced by many parameters, including: test specimen dimensions; test specimen state (orientation, structure, internal stresses); specimen preparation; thermal history of specimen; stress and
29、strain; temperature of test; duration of test; chemical environment; method of application of stress and strain; failure criterion. By keeping all but one parameter constant, the relative influence of the variable parameter on ESC can be assessed. The main objective of ESC measurements is to determi
30、ne the relative effect of chemical media exposure on plastics (test specimens and articles). The measurements may also be used to evaluate the influence of the moulding conditions upon the quality of an article when the failure mode corresponds to that obtained in actual service. It is almost imposs
31、ible, however, to establish any direct correlation between the results of short-duration ESC measurements on test specimens and the actual service behaviour of articles, because the behaviour of the latter is likely to be more complex than that of test specimens. EN ISO 22088-1:2006blank1Plastics De
32、termination of resistance to environmental stress cracking (ESC) Part 1: General guidance 1 Scope 1.1 This part of ISO 22088 provides information and general guidance relevant to the selection of the test method to be used to determine environmental stress cracking (ESC). 1.2 Part 2 describes a meth
33、od in which a test specimen is subjected to a constant tensile load, while immersed in a stress cracking agent at a specified temperature. The time and/or stress at which the specimen breaks is recorded. 1.3 Part 3 describes a method in which strips of plastic are subjected to a fixed flexural strai
34、n and exposed to a stress cracking agent for a predetermined period. 1.4 Part 4 describes a method in which a hole of specified diameter is drilled in a specimen and an oversized steel ball or pin is inserted into the hole while the test specimen is brought into contact with a stress cracking agent.
35、 1.5 Part 5 describes a method in which a constant tensile deformation is applied to a specimen which is immersed in a stress cracking agent at a temperature selected for testing. 1.6 Part 6 describes a method in which a slowly increasing strain is applied to a specimen immersed in a stress cracking
36、 agent. 1.7 These methods are applicable to thermoplastic materials only. 1.8 These are essentially ranking tests and are not intended to provide data to be used for design or performance prediction. 2 Normative references The following referenced documents are indispensable for the application of t
37、his document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 150, Raw, refined and boiled linseed oil for paints and varnishes Specifications and methods of test ISO 293, Plastics Com
38、pression moulding of test specimens of thermoplastic materials ISO 294-1, Plastics Injection moulding of test specimens of thermoplastic materials Part 1: General principles, and moulding of multipurpose and bar test specimens ISO 2818, Plastics Preparation of test specimens by machining EN ISO 2208
39、8-1:20062 3 Terms and definitions The following terms apply to all parts of ISO 22088 except as otherwise indicated: 3.1 test temperature temperature at which the test specimens are in contact with the test medium while being stressed 3.2 test period time during which the test specimens are in conta
40、ct with the test medium while being stressed 3.3 test medium liquid, gas, paste, solid or other chemical medium selected for contact with the test specimens during the test 3.4 ESC index general ratio of the value of the failure-indicative property determined in the test medium to that determined in
41、 a reference medium (usually air), measured at the same test temperature after the same test period 3.4.1 ESC index ISO 22088-3 ratio of the value of the failure strain determined in the test medium to that determined in the reference medium (usually air) for the same time of exposure 3.4.2 ESC inde
42、x ISO 22088-6 normalized value of the departure stress that gauges the ESC susceptibility of different materials to a particular environment 4 Principles of the test 4.1 In Part 2, a test specimen is subjected to a constant tensile load while immersed in a stress cracking agent at a specified temper
43、ature. Three methods may be used. Method A determines the stress required to produce rupture at 100 h. Method B determines the time to rupture at a specified constant tensile stress. In method C, the time to rupture for a series of applied stresses is plotted to determine if the time to rupture meet
44、s a specified agreed-upon stress. 4.2 In Part 3, strips of plastic are subjected to a fixed flexural strain and exposed to a stress cracking agent for a predetermined period. Using a series of forms with decreasing radii, increasingly higher strains are produced in the outer surface. After a specifi
45、ed exposure to the stress cracking agent, specimens are removed, inspected and tested for the indicative property, such as tensile strength. 4.3 In Part 4, a hole of specified diameter is drilled in the specimen and an oversized steel ball or pin is inserted into the hole while the test specimen is
46、brought into contact with a stress cracking agent. After a specified period of exposure, specimens are inspected and/or tested for the indicative property. In some cases, a parallel test conducted in air is carried out for comparison purposes. 4.4 In Part 5, a constant tensile deformation is applied
47、 to a specimen immersed in a stress cracking agent at a temperature selected for testing. The ESC of the test material is determined by comparing the amount of deviation of a defined critical stress determined in the stress cracking medium from that determined in air. 4.5 In Part 6, a slowly increas
48、ing strain is applied to a specimen immersed in a stress cracking agent. Testing is conducted at relatively low strain rates to enhance the effect of the stress cracking medium on the specimen. Development of crazes causes the strain to be taken up by the crazes so that the stress is reduced compare
49、d to tests conducted in an inert environment. EN ISO 22088-1:200635 Applicability of the test method 5.1 Environmental stress cracking tests are used as quality control tools and in research and development to evaluate stress crack resistance. 5.2 When selecting a test method, it is important to consider the types of stress and strain a material will experience in service. Care must be taken when using constant strain test methods, such as the bent strip method or the pin i
