1、 Reference number ISO/TR 12391-2:2002(E) ISO 2002TECHNICAL REPORT ISO/TR 12391-2 First edition 2002-12-15 Gas cylinders Refillable seamless steel Performance tests Part 2: Fracture performance tests Monotonic burst tests Bouteilles gaz Rechargeables en acier sans soudure Essais de performance Partie
2、 2: Essais de mode de rupture Essais de rupture monotoniqueISO/TR 12391-2:2002(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed t
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5、is found, please inform the Central Secretariat at the address given below. ISO 2002 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permiss
6、ion in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2002 All rights reserve
7、dISO/TR 12391-2:2002(E) ISO 2002 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope 1 2 References. 1 3 Symbols . 2 4 Background information 2 5 Experimental test programme . 4 5.1 Types of cylinder tested. 4 5.2 Material properties tests. 6 5.3 Description of the flawed-cylinde
8、r burst test. 7 6 Flawed-cylinder burst test results. 9 6.1 Flawed-cylinder burst test procedure. 9 6.2 Flawed-cylinder burst test results for group A materials. 10 6.3 Flawed-cylinder burst test results for group B materials. 11 6.4 Flawed-cylinder burst test results for group C materials. 11 6.5 F
9、lawed-cylinder burst test results for group D materials. 11 6.6 Flawed-cylinder burst test results for group E materials . 12 6.7 Flawed-cylinder burst test results for tests conducted under special conditions 12 7 Discussion . 12 7.1 Background . 12 7.2 ISO 9809-2 flawed-cylinder burst test procedu
10、res and acceptance criteria. 13 7.3 Analysis by WG 14 to relate the flawed-cylinder burst test to Charpy-V-notch energy values . 14 7.4 Adjustment to the measured P f /P sratio to account for the local cylinder wall thickness . 15 8 Summary and conclusions 16 Annex A (informative) Evaluation of the
11、measurement uncertainty in the flawed-cylinder burst test 113 Bibliography . 116 ISO/TR 12391-2:2002(E) iv ISO 2002 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing I
12、nternational Standards is normally carried out through ISO technical committees. Each member body interested in a subject 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
13、 with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (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 tech
14、nical committees is to prepare International Standards. Draft International Standards adopted by the technical committees 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. In exceptional ci
15、rcumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report
16、is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. 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 for id
17、entifying any or all such patent rights. ISO/TR 12391-2 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 3, Cylinder design. ISO/TR 12391 consists of the following parts, under the general title Gas cylinders Refillable seamless steel Performance tests: Part 1: Philosoph
18、y, background and conclusions Part 2: Fracture performance tests Monotonic burst tests Part 3: Fracture performance tests Cyclical burst tests Part 4: Flawed-cylinder cycle test ISO/TR 12391-2:2002(E) ISO 2002 All rights reserved vIntroduction Gas cylinders as specified in ISO 9809-1 have been const
19、ructed of steel with a maximum tensile strength of less than 1 100 MPa. With the technical changes in steel-making using a two-stage process, referred to as ladle metallurgy or secondary refining, significant improvement in mechanical properties have been achieved. These improved mechanical properti
20、es provide the opportunity of producing gas cylinders with higher tensile strength and which achieve a lower ratio of steel weight to gas weight. The major concern in using steels of higher tensile strength with correspondingly higher design wall stress is safety throughout the life of the gas cylin
21、der. When ISO/TC 58/SC 3 began drafting ISO 9809-2, Working Group 14 was formed to study the need for additional controls for the manufacture of steel gas cylinders having a tensile strength greater than 1 100 MPa. This part of ISO/TR 12391 presents all of the specific test results of the monotonic,
22、 flawed-cylinder burst tests that were conducted in order to evaluate the fracture performance of cylinders ranging in tensile strength from less 750 MPa to greater than 1 210 MPa. TECHNICAL REPORT ISO/TR 12391-2:2002(E) ISO 2002 All rights reserved 1Gas cylinders Refillable seamless steel Performan
23、ce tests Part 2: Fracture performance tests Monotonic burst tests 1 Scope This part of ISO/TR 12391 is a summary and compilation of the test results obtained during the development of the “Flawed-Cylinder Burst Test”. The concept and development of the flawed cylinder burst test is described in ISO/
24、TR 12391-1. The test is a method for evaluating the fracture performance of steel cylinders that are used to transport high pressure, compressed gases. In this part of ISO/TR 12391, test results are reported for several hundred flawed cylinder burst tests that were conducted on seamless steel cylind
25、ers ranging in tensile strength from less than 750 MPa up to about 1 400 MPa. This test method has been shown to reliably predict the fracture performance of seamless steel cylinders. The test method is intended to be used both for the selection of materials and design parameters in the development
26、of new cylinder designs as well as for an efficient quality control test to be used during the production of cylinders. 2 References ISO 148:1983, Steel Charpy impact test (V-notch) ISO 6892:1998, Metallic materials Tensile testing at ambient temperature ISO 9809-1:1999, Gas cylinders Refillable sea
27、mless steel gas cylinders Design, construction and testing Part 1: Quenched and tempered steel cylinders with tensile strength less than 1 100 MPa ISO 9809-2:2000, Gas cylinders Refillable seamless steel gas cylinders Design, construction and testing Part 2: Quenched and tempered steel cylinders wit
28、h tensile strength greater than or equal to 1 100 MPa ISO/TR 12391-1, Gas cylinders Refillable seamless steel Performance tests Part 1: Philosophy, background and conclusions ISO/TR 12391-3, Gas cylinders Refillable seamless steel Performance tests Part 3: Fracture performance tests Cyclical burst t
29、ests ISO/TR 12391-2:2002(E) 2 ISO 2002 All rights reserved3 Symbols A is the elongation expressed as a percentage (= d/t d ); d is the flaw depth, expressed in millimetres (= A t d ); D is the outside diameter of the cylinder, expressed in millimetres; l ois the flaw length, expressed in millimetres
30、 (= n t d ); n represents multiples of t d(= l o /t d ); P fis the failure pressure measured in the flawed-cylinder burst test expressed in bar. P his the calculated design test pressure for the cylinder, expressed in bar; P sis the calculated design service pressure for the cylinder, expressed in b
31、ar; R eais the actual measured value of yield strength, expressed in megapascals; R g, maxis the maximum value of tensile strength guaranteed by the manufacturer, expressed in megapascals; R g, minis the minimum value of tensile strength guaranteed by the manufacturer, expressed in megapascals; R mi
32、s the actual measured value of tensile strength expressed in megapascals; t ais the actual measured wall thickness at the location of the flaw, expressed in millimetres; t dis the calculated minimum design wall thickness, expressed in millimetres. 4 Background information High-pressure industrial ga
33、ses (such as oxygen, nitrogen, argon, hydrogen, helium) are stored and transported in portable steel cylinders. These cylinders are designed, manufactured and maintained in accordance with ISO 9809-1, ISO 9809-2, or national specifications such as those of the U.S. Department of Transportation (DOT)
34、 49 CFR Part 178 1 . The cylinders are constructed from specified alloy steels that are generally modified versions of steels such as AISI 4130 and AISI 4140 2or equivalent steels made to other national specifications. The cylinders are of seamless construction and are manufactured by either a forgi
35、ng process, a tube drawing process or a plate drawing process. The required mechanical properties are obtained by using an austenitizing, quenching and tempering heat treatment. Typical sizes of these cylinders are 100 mm to 250 mm in diameter, 500 mm to 2 000 mm in length, and 3 mm to 20 mm in wall
36、 thickness. Typical working pressure ranges are 100 bar to 400 bar. Until recently, the tensile strength of the steels used in the construction of such cylinders has been limited to a maximum of about 1 100 MPa. This limitation for the maximum tensile strength occurs because the fracture toughness o
37、f the steels decreases with increase in the tensile strength, and above a tensile strength of about 1 100 MPa the fracture toughness was not adequate to prevent fracture of the cylinders. Recently developed new alloy steels that are modifications of the AISI 4130 and AISI 4140, and which have both h
38、igh tensile strength and high fracture toughness make it possible to construct lighter cylinders with higher tensile strength steels. This permits the use of cylinder designs in which the stress in the cylinder wall is increased for a constant wall thickness. The use of higher strength steels will t
39、herefore achieve a lower ratio of steel weight to gas weight that reduces shipping and handling costs. ISO/TR 12391-2:2002(E) ISO 2002 All rights reserved 3A major concern in using higher strength steels for cylinder construction and correspondingly higher design wall stress is the ability to mainta
40、in the same level of safety throughout the life of the cylinder. In particular, increasing the tensile strength of the steels and increasing the stress in the wall of the cylinders could make the cylinders less fracture resistant than cylinders made from steels with the traditionally-used lower tens
41、ile strength levels. In order to use steels with strength levels higher than 1 100 MPa, it was determined that new requirements were needed to assure adequate fracture resistance of the cylinders. To develop these requirements, a Working Group on Cylinder Fracture (WG14) was formed under ISO/TC 58/S
42、C 3. WG 14 was assigned the task of “developing a suitable test method and specifications to assure adequate fracture resistance for gas cylinders made from steels with tensile strengths greater than 1 100 MPa”. WG14 decided that the test method and specifications that were developed should demonstr
43、ate that the overall “fracture resistance” of cylinders made from higher strength steels was equivalent to that of cylinders made from lower strength steels. Fracture resistance of the cylinder is defined as the adequate fracture initiation strength in the presence of a crack-like flaw to assure lea
44、k rather than fracture performance of the cylinder at a specified failure pressure (usually the marked service pressure of the cylinder). The test methods and procedures that have previously been used to evaluate the fracture performance of high pressure cylinders have been based either on fracture
45、mechanics tests and analysis 3 or have been based on empirical correlations with the Charpy-V-notch (CVN) test impact energy 4. The objectives of these tests and analyses are to predict the fracture initiation stress (or pressure) and fracture mode (leak or unstable fracture). The fracture mechanics
46、 tests and analysis showed that to provide adequate fracture resistance, the cylinder wall should be in the plane-stress fracture state and that the fracture should occur under elastic-plastic conditions. To reliably evaluate the fracture performance of cylinders in the plane-stress fracture state r
47、equires that an elastic-plastic fracture mechanics analysis (i.e. J Ic , J R ) be conducted. Using the fracture mechanics analysis approach to evaluate fracture performance may require that a complex and expensive finite-element analysis be done for each specific type of flaw on each specific cylind
48、er design to establish the J Icor J Rrequirements for adequate fracture resistance. Also, the J Icmaterials property test required to evaluate the cylinder material is expensive and time-consuming. Such costly and time-consuming tests, have not proven to be practical for use with the high volume cyl
49、inder production. Empirical correlations have been used to predict the fracture performance of cylinders. These empirical correlations relate the fracture initiation stress level for specific flaw types to the Charpy-V-notch (CVN) test impact energy. Although the Charpy-V-notch (CVN) test is useful for evaluating the quality of cylinders during production, the Charpy-V-notch (CVN) test alone may not be a reliable means to evaluate the fracture resistance of new designs of st
