EN 1252-2:2001

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kriogene posode - Materiali - 2. del: Zahtevana žilavost za temperature med –80 °C in –20 °CKryo-Behälter - Werkstoffe - Teil 2: Anforderungen an die Fähigkeit bei Temperaturen zwischen -80°C und -20°CRécipients cryogéniques - Matériaux - Partie 2: Exigences de ténacité pour les températures entre - 80°C et - 20°CCryogenic vessels - Materials - Part 2: Toughness requirements for temperatures between -80°C and -20°C23.020.40Proti mrazu odporne posode (kriogenske posode)Cryogenic vesselsICS:Ta slovenski standard je istoveten z:EN 1252-2:2001SIST EN 1252-2:2002en01-maj-2002SIST EN 1252-2:2002SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1252-2April 2001ICS 23.020.40English versionCryogenic vessels - Materials - Part 2: Toughness requirementsfor temperatures between -80 °C and -20 °CThis European Standard was approved by CEN on 19 January 2001.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. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1252-2:2001 ESIST EN 1252-2:2002

Page 2EN 1252-2:2001ContentsPageForeword.3Introduction.41Scope.42Normative references.43Terms and definitions.44Requirements for steels with specified yield strength
460 N/mm².54.1General.54.2Temperature adjustments.64.3Procedure for base material lower than 10 mm thick.65General test requirements.75.1Sub-sized specimens.75.2Sub-sized specimens for components from which it is not possible to extract specimens ofsection size equal to the reference thickness.76Welds.87Requirements for aluminium and aluminium alloys, copper and copper alloys and austeniticstainless steels.8Annex ZA (informative) Relationship of this document with EC Directives.19Annex ZB (informative) Case proposal - Technical justification for the temperature adjustment term.20ZB.1General.20ZB.2The brittle fracture concept.20ZB.3Assumptions for the calculation of the minimum operating temperature.21ZB.4Temperature adjustment term.22ZB.5Literature.22SIST EN 1252-2:2002

Page 3EN 1252-2:2001ForewordThis European Standard has been prepared by Technical Committee CEN/TC 268 "Cryogenic vessels", thesecretariat of which is held by AFNOR.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by October 2001, and conflicting national standards shall be withdrawn at the latestby October 2001.For relationship with EC Directive(s), see informative Annex ZA, which is an integral part of this standard.This document also supports the objectives of the framework Directives on Transport of Dangerous Goods. Thisstandard has been submitted for reference into the RID and/or the technical annexes of the ADR.Therefore, the standards listed in the normative references and covering basic requirements of the RID/ADR notaddressed within the present document are normative only when the standards themselves are referred to in theRID and/or in the technical annexes of the ADR.This European Standard is composed of the following parts :EN 1252-1Cryogenic vessels - Materials - Part 1: Toughness requirements for temperatures below - 80 CEN 1252-2Cryogenic vessels - Materials - Part 2 : Toughness requirements for temperatures between- 80°C and - 20°CAccording to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,Switzerland and the United Kingdom.SIST EN 1252-2:2002

Page 4EN 1252-2:2001IntroductionThe use of materials at low temperatures entails special problems which have to be addressed. Consideration hasto be given, in particular, to changes in mechanical characteristics, expansion and contraction phenomena and thethermal conduction of the various materials. The most important property to be considered is the materialtoughness at low temperature.1 ScopeThis European Standard specifies the toughness requirements of the metallic materials for use at a temperaturebetween - 80 °C and - 20 C ensuring suitability for use for the cryogenic vessels.Fine grain and low alloyed steels with specified yield strength
460 N/mm², aluminium and aluminium alloys,copper and copper alloys and austenitic stainless steels are covered by this standard.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendements).EN 10045-1, Metallic materials - Charpy impact test - Part 1 : Test methodEN 288-3 :1992, A1 :1997, Specification and approval of welding procedures for metallic materials - Part 3 :Welding procedure tests for the arc welding of steels3 Terms and definitionsFor the purposes of this European Standard, the following terms and definitions apply :3.1minimum metal temperature TMthe lowest temperature defined for each of the following conditions (see also 3.2 and 3.3) : temperature during normal operations ; temperature during start up and shut down procedures ; temperature which may occur during possible process upsets ; temperature which may occur during pressure or leak testing.3.2temperature adjustment term TSterm relevant to the calculation of the design reference temperature TR and dependent on the pressure inducedprincipal membrane stress at the appropriate minimum metal temperature.SIST EN 1252-2:2002

Page 5EN 1252-2:20013.3design reference temperature TRthe temperature used for determining the impact energy requirements.TR is determined by adding the adjustment TS to the minimum metal temperature TM :TR = TM+TSAll applicable combinations of the temperatures TM and TS shall be considered and the lowest possible TR-valueshall be used for the determination of the required material impact test temperature.3.4impact test temperature TKVthe temperature at which the required impact energy has to be achieved (see clause 5).3.5impact energy KVthe energy determined from Charpy-V-notch tests performed in accordance with EN 10045-1.3.6reference thickness eBthe thickness of a component to be used to relate the design reference temperature TR of the component with itsrequired impact test temperature TKV, (see Figures 1 to 5). The reference thickness eB is based on the nominalthickness (including corrosion allowance) and shall be as defined in Table 6. For butt welded components eB is thenominal wall thickness of the component at the edge of the weld preparation.4 Requirements for steels with specified yield strength
460 N/mm²4.1 GeneralThis method, based on fracture mechanics can be used to determine the requirements to avoid brittle fracture in C,CMn, fine grain and low alloy steels with a specified minimum yield strength
460 N/mm².In this procedure the impact test temperature TKV is not equal to the design reference temperature TR.Parent material, welds and HAZ shall meet the impact energy KV and impact test temperature TKV requirements inTable 1 for design reference temperatures TR and reference thicknesses eB. Values of TR shall be calculated fromTM using the values of TS given in 4.2.For materials with a specified minimum yield strength > 310 N/mm² the impact energy at TKV given in Figure 1 andFigure 2 shall be 40 J. Where 27 J is specified in the product standard, Figure 3 for the post-weld heat treatedcondition applies. For the as welded case with minimum yield strength in the range > 310 N/mm² and
360 N/mm²Figure 4 applies. For minimum yield strength > 360 N/mm² Figure 5 applies.Table 1 — Impact energy requirementsFigure defining required TKvSpecified minimum yieldstrength of base materialN/mm²Required impact energy KV(on 10 mm x 10 mm test pieces)JNon welded andpost-weld heattreatedAs welded 31027124012> 310,
36027344012> 3602735SIST EN 1252-2:2002

Page 6EN 1252-2:20014.2 Temperature adjustmentsTs is a temperature adjustment which can be used if the pressure induced principal membrane stress does notexceed the percentage of the maximum allowable design stress or 50 N/mm² given in Table 2.Table 2 — Temperature adjustmentsPercentage of maximum allowable design stressMembranestress bCondition> 75 %;
100 % 75 % 50 % 50 N/mm²Non welded or post-weldheat treated condition a0 °C+10 °C+25 °C+50 °CAs welded condition andreference thickness< 30 mm0 °C0 °C0 °C+40 °Ca Also applicable for equipment where all nozzles and non-temporary welded attachments are first welded to vesselcomponents and these sub-assemblies are post-weld heat treated before being assembled into the equipment bybutt-welding, but the main seams are not subsequently post-weld heat treated.b In this case the membrane stress should take account of internal and external pressure and dead weight.4.3 Procedure for base material lower than 10 mm thickMinimum TR values are given in Table 3 for use when the base material is less than 10 mm thick and the testingtemperature TKV is 20 °C. The impact energy requirements are as specified in the relevant materials standards.If these materials are to be used below the TR values given in Table 3 the testing shall be performed in accordancewith the relevant curve for 10 mm in Figure 1 to Figure 5. The required energies for the sub-sized specimens aregiven in Table 4.Table 3 — Minimum TR-values for base material less than 10 mm thick and tKV = 20 °CThicknessmmAW°CPWHT°C8-20-356-25-404-40-552-55-70SIST EN 1252-2:2002

Page 7EN 1252-2:20015 General test requirementsWhere impact tests are required they shall be Charpy V-notched tests in accordance with EN 10045-1. The impactenergy requirements shall be met in the base material, heat affected zone and weld metal. The specimen positionshall be in accordance with EN 288-3:1992/A1:1997, 7.4.4. From each sample three specimens shall be tested foreach of the required positions and test temperatures. The mean value of the three specimens shall be at leastequal to the impact energy requirement. Only one specimen may show a lower value, but this value shall not beless than 70 % of this requirement.The required values for base material refer to the transverse direction. If transverse properties are not obtainable,the minimum impact energy requirements specified for transverse test pieces shall be multiplied by the factor 1,5for C, CMn, fine grained and low alloyed steels with a minimum specified yield strength
460 N/mm². (For othermaterials refer to product standard).5.1 Sub-sized specimensIf the base material is less than 10 mm thick the energy requirements are given in Table 4.Table 4 — Impact requirements for sub-sized Charpy V-notched specimen if the base material is less than10 mm thickDimensions in millimetresSpecimen geometrymm x mm10 x 1010 x 7,510 x 527 J22 J19 J40 J32 J28 JAlternatively, where proportional reduced energy requirements are preferred, Table 5 shall be applied.5.2 Sub-sized specimens for components from which it is not possible to extract specimens ofsection size equal to the reference
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