1、 ISO 2014 Through-thickness characteristics for steel products Caractristiques garanties dans le sens de lpaisseur pour produits en acier INTERNATIONAL STANDARD ISO 7778 Second edition 2014-03-01 Reference number ISO 7778:2014(E) ISO 7778:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED DO
2、CUMENT ISO 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission
3、can be requested 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 ISO 7778:2014(E) ISO 2014 Al
4、l rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Requirements 1 4 Designation 2 5 Number and selection of test pieces 2 5.1 Test unit for flat products 2 5.2 Test unit for sections 2 5.3 Sampling . 2 6 Test methods . 3 6.1 Test pieces . 3 6.2 Tens
5、ile test 3 Bibliography 7 ISO 7778:2014(E) 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
6、 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 with ISO, also take part in the work. ISO collaborates closely with the International Elect
7、rotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types o
8、f ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). 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 hel
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11、llowing URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 3, Steels for structural purposes. This second edition cancels and replaces the first edition (ISO 7778:1983), which has been technically revised.iv ISO 2014 All rights
12、reserved ISO 7778:2014(E) Introduction Steel products as normally manufactured generally exhibit deformation properties in the direction perpendicular to the surface of the product, which are different from those obtained in the direction of the surface. It is, however, possible to improve these def
13、ormation properties by taking particular precautions when the steel is manufactured. Experience has shown that measurement of the value for reduction of area, measured by means of a tensile test piece sampled in the direction of thickness of the product perpendicular to its surface, is the best way
14、to characterize these properties. However, the choice of one quality of steel exhibiting properties of this nature does not necessarily ensure the safety of a structure of which certain components are stressed perpendicular to their surface. Precautions should be taken both at the design and fabrica
15、tion stage, and more particularly during welding, so as to minimize stresses in the through-thickness direction. ISO 2014 All rights reserved v Through-thickness characteristics for steel products 1 Scope This International Standard specifies the criteria for through-thickness reduction of area prop
16、erties specified in the direction of thickness perpendicular to the surface. This International Standard also specifies the test conditions by which conformance to the specified criteria is evaluated. This International Standard applies to fully killed steel with a specified minimum yield strength o
17、r proof strength 960 MPa and supplied as plates, wide flats, or sections of thickness from 15 mm to 400 mm. The application of this International Standard to products 400 mm or having minimum specified yield strengths or proof strengths 960 MPa will be the subject of agreement when ordering. The req
18、uirements of this International Standard supplement other International Standards that specify the qualities of products (plate, wide flats, and sections). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its a
19、pplication. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 377, Steel and steel products Location and preparation of samples and test pieces for mechanical testing ISO 404, Steel and
20、steel products General technical delivery requirements ISO 6892-1, Metallic materials Tensile testing Part 1: Method of test at room temperature ISO 17577:2006, Steel Ultrasonic testing for steel flat products of thickness equal to or greater than 6 mm 3 Requirements Table 1 gives the minimum averag
21、e values and the minimum individual values for the reduction of area, which the products shall satisfy according to their class. Table 1 Minimum average and individual values Class Minimum average value a Minimum individual value Z15 15 % 10 % Z25 25 % 15 % Z35 35 % 25 % aAverage of three tests. NOT
22、E Products delivered in accordance with this International Standard can be subject to ultrasonic testing according to published standards (e.g. ASTM, JIS, EN, ISO, etc.) upon agreement (see, for example, ISO 630-1). INTERNATIONAL ST ANDARD ISO 7778:2014(E) ISO 2014 All rights reserved 1 ISO 7778:201
23、4(E) 4 Designation The qualities of steel with specified through-thickness properties shall be marked by adding a plus sign and the class number after the designation of the steel. EXAMPLE S355D+Z35. 5 Number and selection of test pieces 5.1 T est unit for flat pr oducts See Table 2. for sulfur 0,00
24、5 %: testing shall be per rolled unit (R) in the same heat treatment condition (parent plate or wide flat); for sulfur 0,005 %: at the option of the manufacturer, the test unit shall be type 1 or type 2. Type 1 testing: per test unit consisting of products from the same heat (H) which have undergone
25、 the same heat treatment and have nominal thicknesses which do not differ by more than 20 % compared with the minimum thickness of the test unit.Ultrasonic testing in accordance to ISO 17577:2006, Table 4, class B2, is mandatory for all the products of the test unit. Type 2 testing: per test unit co
26、nsisting of products from the same heat which have undergone the same heat treatment and have a total mass of 40 t (L) and have nominal thicknesses which do not differ by more than 20 % compared with the minimum thickness of the test unit. Table 2 Test unit Sulfur 0,005 % S u l f u r 0 , 0 0 5 % Fre
27、quency R Type 1 Type 2 H L Ultrasonic testing Mandatory 5.2 Test unit for sections The tests shall be carried out, unless otherwise agreed, per test unit consisting of products from the same heat, which have undergone the same heat treatment, and have a total mass of 40 t and have nominal thicknesse
28、s which do not differ by more than 20 % compared with the minimum thickness of the test unit. 5.3 Sampling 5.3.1 Flat products For each test unit, three tensile test pieces shall be taken from the thickest product, from one end. In case of continuous cast, the sample shall be taken from the centre o
29、f width or nearby or from the 1/4 width or nearby (see Figure 1). In case of ingot cast, the sample shall be taken from the centre of width or nearby. 5.3.2 Sections For each test unit, three tensile test pieces shall be taken from the thickest product, from one end. The sampling position shall be t
30、he flange unless otherwise agreed at the time of the order. The location of the sample shall be in accordance with ISO 377.2 ISO 2014 All rights reserved ISO 7778:2014(E) 6 Test methods 6.1 Test pieces 6.1.1 The reduction of area shall be measured using a cylindrical test piece. The diameter of the
31、test piece, which depends on the thickness of the product, is given in Table 3. The effective length, L c , of the cylindrical part of the test piece shall be 1,5 times its diameter. Table 3 Diameter of test pieces Dimensions in millimetres Product thickness Diameter of test piece t 25 d 0= 6 or 10
32、t 25 d 0= 10 6.1.2 When it is not possible to machine a test piece in the thickness of the product, the extension pieces may be attached by welding. Welding may be carried out in accordance with any suitable method (e.g. friction welding), but shall be chosen in a way which results in a minimum heat
33、-affected zone. The effective length, L c , shall be outside the heat-affected zones. 6.1.3 Unless otherwise agreed when ordering, the manufacturer may use either a test piece with extension pieces attached by welding or a test piece machined in the whole thickness of the product (see Figure 2). The
34、 use of test pieces of type b or c is recommended when it is necessary to examine the surface properties of the product. 6.1.4 For products thicker than 80 mm, when it is not possible to machine a test piece in the whole thickness, the length of the test piece shall be such that the effective length
35、, L c , contains the 1/4 thickness position of the product (see Figure 2, type d). NOTE Upon request, an additional test piece can be machined containing the 1/2 thickness position of the product. 6.2 Tensile test 6.2.1 Measurement of reduction of area The tensile test shall be carried out in accord
36、ance with the requirements of ISO 6892-1. The assessment of results is based on a sequential method (as defined in ISO 404). ISO 2014 All rights reserved 3 ISO 7778:2014(E) The reduction of area Z is defined by Formula (1): (1) whereS 0 is the original cross-sectional area of the test piece, ;S is t
37、he final cross-sectional area of the test piece after fracture, ;d 1and d 2 are the measurements of two perpendicular diameters (where the fracture is elliptical in shape, d 1and d 2correspond to the axes of the ellipse). 6.2.2 Assessment of results 6.2.2.1 The average value of a set of three test p
38、ieces (see 6.1.1) shall meet the specified requirement (see Table 1). One individual value may be below the specified minimum average value, provided that it is not less than the specified minimum individual value. 6.2.2.2 If the conditions in 6.2.2.1 are not satisfied, then an additional set of thr
39、ee test pieces shall be taken from the same sample and tested. The test unit is conformed, after testing the second set and after the following conditions being satisfied simultaneously: the average value of six tests shall be equal to or greater than the specified minimum average value; not more th
40、an two of six individual values may be lower than the specified minimum average value; not more than one of six individual values may be lower than the specified minimum individual value. 6.2.2.3 If the conditions in 6.2.2.2 are not satisfied, the sample product is rejected and retests are carried o
41、ut on the remainder of the test unit, if applicable (see 5.1 and 5.2). 6.2.3 Retest Except in cases where the test unit is the rolled unit, a new set of three tests shall be carried out on each of two different products from the remainder of the test unit; those two series of tests shall meet the re
42、quirements. In this case, 6.2.2.2 and 6.2.2.3 no longer apply. Each rolled unit on which the tests do not meet the requirements shall be rejected. 6.2.4 Invalid tests A test is invalid if the test piece was defectively machined, the test piece was incorrectly mounted in the test machine, the test ma
43、chine malfunctioned, or the test piece fractured in the weld metal or in the heat-affected zone when using extension pieces.4 ISO 2014 All rights reserved ISO 7778:2014(E) Results from invalid tests shall not be considered. 6.2.5 Sorting and reprocessing Sorting and reprocessing shall be in accordan
44、ce with ISO 404. The manufacturer has the right to carry out sorting or reprocessing (e.g. heat treatment, machining, rolling, drawing, etc.) of non-conforming products, either before or after retests, and to submit these products as a new test unit in accordance with 5.1 and 5.2. Where no reprocess
45、ing, only sorting, has been applied, the new inspection procedure shall only apply to the requirements which were not complied with during the first inspection and testing. The manufacturer shall inform the inspection representative which method of sorting or reprocessing was used. Key 1 rolling dir
46、ection 2 centre of width 3 1/4 of width 4 test piece 5 sample NOTE The test coupons are sampled according to 5.3. F i g u r e 1 L o c a t i o n o f s a m p l e s f o r f l a t p r o d u c t s ISO 2014 All rights reserved 5 ISO 7778:2014(E) Key 1 extension pieces attached by welding 2 type a 3 type b
47、 4 type c 5 type d a d 0= 6 mm or 10 mm according to Table 3. b d 0= 10 mm according to Table 3. Figure 2 Sampling and preparation of test pieces6 ISO 2014 All rights reserved ISO 7778:2014(E) Bibliography 1 ASTM A435M, Standard Specification for Straight-Beam Ultrasonic Examination of Steel Plates
48、2 ASTM A578M, Standard Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for Special Applications 3 EN 10160, Ultrasonic testing of steel flat product of thickness equal or greater than 6 mm (reflexion method) 4 EN 10306, Iron and steel Ultrasonic testing of H beams with
49、parallel flanges and IPE beams 5 JIS G 0801, Ultrasonic testing of steel plates for pressure vessels 6 JIS G 0901, Classification of structural rolled steel plate and wide flat for building by ultrasonic test ISO 2014 All rights reserved 7 ISO 7778:2014(E) ISO 2014 All rights reserved IC S 77.140.50 Price based on 7 pages
