1、BRITISH STANDARD Cryogenic vessels - Materials - Part 2: Toughness requirements for temperatures between -80 OC and -20 OC The European Standard EN 1252-2:2001 has the status of a British Standard ICs 23.020.40 BS EN 125 2-2:200 1 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LA
2、W BS EN 1252-2:2001 National foreword This British Standard is the official English language version of EN 1252-2:2001. The UK participation in its preparation was entrusted to Technical Committee PVE18, Cryogenic vessels, which has the responsibility to: - - aid enquirers to understand the text; pr
3、esent to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed: monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained
4、 on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facil
5、ity of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligat
6、ions. This British Standard, having been prepared under the direction of the Engineering Sector policy and Strategy Committee. was uublished Summary Of pages This document comprises a front cover, an inside front cover, the EN title page, oages 2 to 22. an inside back cover and a back cover. AY , un
7、der the authority of the Standards policy and Strategy Committee on 23 August 2001 The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd.No. (Date 1 Comments %? BSI 23 August 2001 I I ISBN O 580 38203 6 EN 1252-2 EUROPE
8、AN STANDARD NORME EUROPENNE EUROPISCHE NORM April 2001 ICs 23.020.40 English version Cryogenic vessels - Materials - Part 2: Toughness requirements for temperatures between -80 “C and -20 “C This European Standard was approved by CEN on 19 January 2001 CEN members are bound to comply with the CENICE
9、NELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any C
10、EN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN me
11、mbers are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy. Luxembourg, Netherlands, Nonvay, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISA
12、TION EUROPISCHES KOMITEE FUR NORMUNG Management Centre: rue de Stascart, 36 8-1050 Brussels O 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1252-2:2001 E Page 2 EN 1252-2:2001 Contents Page Foreword . 3 1 Scope . 4 2 Normati
13、ve references 4 3 Terms and definitions 4 4 Requirements for steels with specified yield strength I 460 N/mm2 . 5 4.1 General . 5 4.2 Temperature adjustments . 6 4.3 . 6 5 General test requirements . 7 5.1 Sub-sized specimens . 7 Introduction 4 Procedure for base material lower than 10 mm thick 5.2
14、6 8 7 Requirements for aluminium and aluminium alloys, copper and copper alloys and austenitic stainless steels 8 Annex ZA (informative) Relationship of this document with EC Directives . 19 Annex ZB (informative) Case proposal - Technical justification for the temperature adjustment term . 20 ZB.l
15、General . 20 ZB.2 The brittle fracture concept . 20 ZB.3 Assumptions for the calculation of the minimum operating temperature 21 adjustment term . 22 22 Sub-sized specimens for components from which it is not possible to extract specimens of section size equal to the reference thickness . O ES1 08-2
16、001 Page 3 EN 1252-2:2001 Foreword This European Standard has been prepared by Technical Committee CENITC 268, Cryogenic vessels, the Secretariat 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 or by endor
17、sement, at the latest by October 2001, and conflicting national standards shall be withdrawn at the latest by 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 Directi
18、ves on Transport of Dangerous Goods. This standard has been submitted for reference into the RID andlor the technical annexes of the ADR. Therefore, the standards listed in the normative references and covering basic requirements of the RIDIADR not addressed within the present document are normative
19、 only when the standards themselves are referred to in the RID and/or in the technical annexes of the ADR. This European Standard is composed of the following parts: EN 1252-1, Cryogenic vessels - Materials - Pari 1: Toughness requirements for temperatures below -80 . EN 1252-2, Cryogenic vessels -
20、Materials - Pari 2: Toughness requirements for temperatures between - 80C and - 20C. According to the CENICENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, F
21、rance, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. O BSI 08-2001 Page 4 EN 1252-2:2001 Introduction The use of materials at low temperatures entails special problems that have to be addressed. Consideration h
22、as to be given, in particular, to changes in mechanical characteristics, expansion and contraction phenomena and the thermal conduction of the various materials. The most important property to be considered is the material toughness at low temperature. 1 Scope This European Standard specifies the to
23、ughness requirements of the metallic materials for use at a temperature between -80 “C and -20 “C ensuring suitability for use for the cryogenic vessels. Fine grain and low alloyed steels with specified yield strength 5 460 Nlmm2, aluminium and aluminium alloys, copper and copper alloys and austenit
24、ic stainless steels are covered by this standard. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For da
25、ted references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendements). EN 10045-1, Metallic mat
26、erials - Charpy impact test - Part Ir Test method. EN 288-3:1992, AI : 1997, Specification and approval of welding procedures for metallic materials - Part 3: Welding procedure tests for the arc welding of steels. 3 Terms and definitions For the purposes of this European Standard, the following term
27、s and definitions apply: 3.1 minimum metal temperature TM the 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 that may occur during possible process u
28、psets; - temperature that may occur during pressure or leak testing. 3.2 temperature adjustment term Ts term relevant to the calculation of the design reference temperature TR and dependent on the pressure induced principal membrane stress at the appropriate minimum metal temperature O BSI 08-2001 P
29、age 5 EN 1252-2:2001 3.3 design reference temperature TR temperature used for determining the impact energy requirements TR is determined by adding the adjustment TS to the minimum metal temperature TM: All applicable combinations of the temperatures Tbl and Ts shall be considered and the lowest pos
30、sible TR-value shall be used for the determination of the required material impact test temperature. 3.4 impact test temperature TKv temperature at which the required impact energy has to be achieved (see clause 5) 3.5 impact energy KV energy determined from Charpy-V-notch tests performed in accorda
31、nce with EN 10045-1 3.6 reference thickness eg thickness of a component to be used to relate the design reference temperature TR of the component with its required impact test temperature TKV (see Figures 1 to 5). The reference thickness eg is based on the nominal thickness (including corrosion allo
32、wance) and shall be as defined in Table 6. For butt welded components eg is the nominal wall thickness of the component at the edge of the weld preparation. 4 Requirements for steels with specified yield strength I460 N/mm2 4.1 General This method, based on fracture mechanics can be used to determin
33、e the requirements to avoid brittle fracture in C, CMn, fine grain and low alloy steels with a specified minimum yield strength I460 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 ener
34、gy KV and impact test temperature Tr;v requirements in Table 1 for design reference temperatures TR and reference thicknesses eg. Values of TR shall be calculated from Tbl using the values of Ts given in 4.2. For materials with a specified minimum yield strength 310 N/mm2 the impact energy at TK“ gi
35、ven in Figure 1 and Figure 2 shall be 40 J. Where 27 J is specified in the product standard, Figure 3 for the post-weld heat treated condition applies. For the as welded case with minimum yield strength in the range 31 O N/mm2 and L 360 N/mmz Figure 4 applies. For minimum yield strength 360 N/mmz Fi
36、gure 5 applies. O BSI 08-2001 Required impact energy KV (on 10 mm x 10 mm test pieces) J 27 40 Specified minimum yield strength of base material N/mm2 Figure defining required TKv Non welded and As welded post-weld heat treated 1 2 1 2 5 310 310, I 360 40 27 27 1 2 3 5 13 14 4.2 Temperature adjustme
37、nts 7, is a temperature adjustment that can be used if the pressure induced principal membrane stress does not exceed the percentage of the maximum allowable design stress or 50 N/mm2 given in Table 2. Table 2 -Temperature adjustments Condition r heat treated condition a As welded condition and refe
38、rence thickness 30 mm Percentage of maximum allowable design stress 75 %; 5 I00 % 31 O N/mm2: requirements of 40 J - (corresponds to KIc = 105 MPa&) O BSI 08-2001 Page 21 EN 1252-2:2001 ZB.3 Defect size: For the defect size a semi-elliptical surface defect with a depth of 0,25 times the wall thickne
39、ss was taken, which corresponds to the provisions of the ASME Code Section III. Loads: The loads are assumed as 1,4 times the yield in the A-W condition. The loads consist of the permitted primary stress and remaining residual stresses. In the PWHT state, loads are assumed to be equivalent to the yi
40、eld point. On these assumptions the minimum operating temperatures are calculated. Assumptions for the calculation of the minimum operating temperature The calculation of the following equation: minimum metal temperature is conducted according to Sandstrm (2) with the : + TKV + AT, - - TK,- Impact t
41、est temperature T27J or T40J ( KIc = 78 MPaJrn or 105 MPaJrn ) K, Stress intensity factor K = p Constant 1/60 O KO Constant 25MPaG AT, Correction term for the influence of the component thickness. The correction term ATe takes into consideration the influence of the wall thickness. The starting fact
42、or of the concept is a wall thickness greater than or equal to 110 mm. If the wall thickness becomes less, this influences the stress condition and has beneficial effects on the brittle fracture safety. The transition from the multi-dimensional strain condition to the level plain strain condition is
43、 taken into account by means of the correction term. In the Sandstrm concept, the influence of the yield point on the size of the plastic zone is also taken into consideration, in addition to the influence of the wall thickness. This leads to a correction terms tps . The correction term is proportio
44、nal to where (T is the yield stress (Re,/Rm)/2 of the material. O BSI 08-2001 Page 22 EN 1252-2:2001 Definition of the temperature displacement AT, by comparison of Ips with the component thickness, t. e = t + 1 10 tps, tps 110 AT, =0,53e - 59, I10 e 60 AT, = 0,97e - 85,60 e 30 AT, =1,8e-l10,30eIO T
45、, is calculated as a function of the impact test temperature TKv and the component thickness. The result of the calculations are the Figures 1 to 5, which show the impact test temperatures as a function of wall thickness for the yield point ranges. Figure I shows the dependence for the condition unw
46、elded andlor post- weld heat treated. From a thickness of 60 mm the impact test temperature is equal to the minimum metal temperature. If the component thickness becomes less, the strain condition is shifted in the direction of plain strain condition. This is taken into consideration with a lower mi
47、nimum metal temperature. ZB.4 Temperature adjustment term In the brittle fracture concept, loads at the level of the yield point and/or 1,4 times the yield point are assumed. If the actual loads are under the maximum permissible loads, this is taken into account with a temperature adjustment term TS
48、. The temperature TR is determined from the minimum metal temperature and TS. The temperature adjustment term has the effect that the material can be used at lower temperatures. The Swedish Standard, like AD-W 10 or BS5500, provides for a temperature adjustment term for loads below the permissible l
49、oad. ZB.5 Literature - (1) Sanz G. Rev. Metal CIT 1980 pp 621-642. - (2) Sandctrm, R. Scandinavian J of Metallurgy 16 (1 987), pp 242-252. - (3) Garwood S.J. and Dervhan JB “The fracture toughness requirements of BS 5500” ASME pressure vessel and piping conference (1 988), paper 88 - PBP-7. O BSI 08-2001 BS EN 125 2-2:2001 BST 389 Chiswick High Road London W4 4AL BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the nternational level. It is incorporated
