1、 ISO 2016 Steel names based on letter symbols Dsignations des aciers fondes sur des lettres symboles TECHNICAL SPECIFICATION ISO/TS 4949 Reference number ISO/TS 4949:2016(E) Second edition 2016-1 1-01 ISO/TS 4949:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published
2、 in Switzerland 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 Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO/TS 4949:2016(E)Foreword iv 1 Sco
4、pe . 1 2 Normative references 1 3 T erms and definitions . 1 4 Principles . 1 4.1 A unique steel name . 1 4.2 Formulation of steel names 1 4.3 Allocation of steel names . 1 5 Reference to product standards . 1 6 Classification of st eel names 2 7 Structure of steel names . 2 7.1 Initial symbol for s
5、teel castings 2 7.2 Steels designated according to their application and mechanical or physical properties (group 1) 2 7.3 Steels designated according to chemical composition (group 2) 4 7.3.1 Non-alloy steels (except free-cutting steels) with an average manganese content 1 % (sub-group 2.1) . 4 7.3
6、.2 Non-alloy steels with an average manganese content 1 %, non-alloy free-cutting steels and alloy steels (except high speed steels) where the average content, by mass, of every alloying element is 5 % (sub-group 2.2) . 4 7.3.3 Alloy steels (except high speed steels) where the average content by mas
7、s of at least one alloying element is 5 % (sub-group 2.3) 5 7.3.4 High speed steel (sub-group 2.4) 5 8 Additional symbols 5 Annex A (normative) Additional symbols indicating special requirements .6 Annex B (normative) Additional symbols indicating type of coating . 7 Annex C (normative) Additional s
8、ymbols indicating treatment condition 8 Bibliography 9 ISO 2016 All rights reserved iii Contents Page ISO/TS 4949:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International
9、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 with ISO, al
10、so take part in the work. ISO collaborates closely with the International Electrotechnical 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.
11、 In particular the different approval criteria needed for the different types of 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 elem
12、ents of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations receive
13、d (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformit y assessment, as well as information about ISOs adh
14、erence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. The committee responsible for this document is ISO/TC 17, Steel. This second edition cancels and replaces the first edition (ISO/TS 4949:2003), which
15、 has been technically revised.iv ISO 2016 All rights reserved TECHNICAL SPECIFICATION ISO/TS 4949:2016(E) Steel names based on letter symbols 1 Scope This document specifies rules for the designation of internationally standardized steel grades by means of symbolic letters and numbers to express app
16、lication and principal characteristics (e.g. mechanical, physical, chemical) so as to provide an abbreviated identification of steel grades. NOTE 1 In order to avoid ambiguity, the principal symbols established according to this document can be supplemented by additional symbols identifying addition
17、al characteristics of the steel or steel product, e.g. suitability for use at high or low temperatures, surface condition, treatment condition, deoxidation. NOTE 2 These rules can also be applied to nationally or regionally standardized steels. 2 Normative references There are no normative reference
18、s in this document. 3 T erms an d definiti ons For the purposes of this document, the terms and definitions in ISO 4948-1, ISO 4948-2 and ISO 6929 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/ /www.el
19、ectropedia.org/ ISO Online browsing platform: available at http:/ /www.iso.org/obp 4 Principles 4.1 A unique steel name There shall be one unique steel name for each steel. 4.2 Formulation of steel names Unless otherwise specified in this document, the symbols used in the steel name shall be written
20、 without spaces. 4.3 Allocation of steel names For steels specified in International Standards, Technical Specifications or Technical Reports, steel names shall be allocated by the relevant subcommittee of ISO/TC 17. 5 Reference to product standards The complete designation of a steel product where
21、quoted in orders or similar contractual documents shall include, in addition to the steel name, an indication of the technical delivery requirement in which the steel is specified. For steels specified in standards this shall be the reference number of the relevant product standard. ISO 2016 All rig
22、hts reserved 1 ISO/TS 4949:2016(E) Details of the structure of the steel name for the steel or steel product shall be provided in the relevant product or dimensional standard. 6 Classific ation of st eel names For the purpose of designation, steel names are classified into two main groups. Group 1:
23、Steels designated according to their application and mechanical or physical properties. See 7.2. Group 2: Steels designated according to their chemical composition and further divided into four sub-groups. See 7.3. 7 Structure of steel names 7.1 Initial symbol for steel castings Where a steel is spe
24、cified in the form of a steel casting, its steel name as specified in 7.2 and 7.3 shall be preceded by the letter G. 7.2 Steels designated according to their application and mechanical or physical properties (group 1) The coding shall comprise the following principal symbols. a) S = structural steel
25、s. P = steels for pressure purposes. L = steels for linepipe. E = engineering steels. Each followed by a number being the specified minimum yield strength in MPa for the smallest thickness range. NOTE 1 The term “yield strength” as used in this document refers to upper or lower yield strength, R eHo
26、r R eL , proof strength, R p , or proof strength total extension, R t , depending on the requirement specified in the relevant product standard. NOTE 2 1 MPa = 1 N/mm 2 . When the specified minimum tensile strength is used instead of the specified minimum yield strength, the letter T shall be added
27、after the principal symbol, e.g. PT. In order to distinguish structural steels of different regions an additional letter “G” may be added, e.g. steel grade SG345, see ISO 630-2. b) B = steels for reinforcing concrete. Followed by a number being the characteristic yield strength in MPa. c) Y = steels
28、 for pre-stressing concrete. Followed by a number being the specified nominal tensile strength in MPa. d) R = steels for or in the form of rails. Followed by a number being the specified minimum Brinell hardness (HBW).2 ISO 2016 All rights reserved ISO/TS 4949:2016(E) e) H = cold rolled flat product
29、s of high strength steels for cold forming. Followed by a number being the specified minimum yield strength in MPa or, where only the tensile strength is specified, the letter T followed by a number being the minimum specified tensile strength in MPa. f) D = flat products for cold forming except tho
30、se in 7.2 (e). Followed by one of the following letters: 1) C for cold rolled products; 2) D for hot rolled products for direct cold forming; 3) X for products the rolled condition of which is not specified; and by two symbols characterizing the steel allocated by the responsible body. See 4.3. g) T
31、 = tinmill products (steel products for packaging). Followed by the following letters: 1) for batch annealed grades, the letter S followed by a number being the specified nominal yield strength in MPa; 2) for continuously annealed grades, the letter H followed by a number being the specified nominal
32、 yield strength in MPa. NOTE 3 In the current version of International Standards for tinmill products ISO 11949:2016, ISO 11950:2016 and ISO 11951:2016, the steel names are designated not only according to the nominal yield strength, but also according to Rockwell HR30T hardness values. Since the la
33、st available techniques should be reflected in International Standards on packaging steels, the possibility of using the tensile test as the reference test for determining the mechanical properties would be considered during the next revision of these International Standards. h) M = electrical steel
34、s. Followed successively by the following: 1) a number being 100 the specified maximum specific loss expressed in W/kg, corresponding to the nominal product thickness, for a magnetic polarization at 50 Hz of i) 1,5 Tesla for semi-finished, non-oriented and normal grain oriented steels, ii) 1,7 Tesla
35、 for reduced loss or high permeability grain oriented steels; 2) a number being 100 the nominal thickness of the product in millimetres; 3) a letter indicating the type of electrical steel, i.e. i) A for non-oriented products, ii) D for non-alloy semi-finished (not finally annealed) products, iii) E
36、 for alloy semi-finished (not finally annealed) products, iv) N for normal grain oriented products, v) S for reduced loss grain oriented products, vi) P for high permeability grain oriented products. NOTE 4 A hyphen is used to separate symbols (1) and (2). ISO 2016 All rights reserved 3 ISO/TS 4949:
37、2016(E) NOTE 5 The symbols to be indicated after the letter M concern electrical steels for use at the industrial frequency of 50 Hz. For other uses such as steel products for relays and high frequency applications, the principal symbols are not yet established. 7.3 Steels designated according to ch
38、emical composition (group 2) 7.3.1 Non-alloy steels (except free-cutting steels) with an average manganese content 1 % (sub-group 2.1) The coding shall comprise successively the following symbols. a) The letter C. b) A number being 100 the specified average percentage carbon content. Where the carbo
39、n content is not specified by a range, the subcommittee responsible for the relevant product standard shall select a suitably representative value. NOTE To distinguish between two similar steel grades, the number indicating carbon content can be increased or decreased by one unit. The coding should
40、be supplemented as follows: E = with specified max sulfur content. R = with specified sulfur content range. D = for wire drawing. C = for cold forming, e.g. cold heading, cold extrusion. S = for springs. U = for tools. W = for welding rod. G = other characteristics followed where necessary, by 1 or
41、2 digits. 7.3.2 Non-allo y st eels with an a v er age mang anese c ont ent 1 %, non-allo y fr ee-cutting st eels and allo y st eels (e x c ept hig h speed st eels) w her e the a v er age c ont ent , by mass, of e v ery allo ying element is 5 % (sub-group 2.2) The coding shall comprise successively t
42、he following symbols. a) A number being 100 the specified average percentage carbon content. Where the carbon content is not specified by a range the subcommittee responsible for the relevant product standard shall select a suitably representative value. NOTE To distinguish between two similar steel
43、 grades, the number indicating carbon content can be increased or decreased by one unit. b) Chemical symbols indicating the alloying elements that characterize the steel. The sequence of symbols shall be in decreasing order of the value of their content; where the values of contents are the same for
44、 two or more elements, the corresponding symbols shall be indicated in alphabetical order. c) Numbers indicating the values of contents of alloy elements. Each number represents the average percentage content of the element indicated multiplied by the factors given in Table 1 and rounded to the near
45、est integer. The numbers referring to the different elements shall be separated by hyphens. However, in order to follow the principle of keeping names as short as practical, one or more of these digits may be omitted as long as there is no danger of confusion with a similar grade.4 ISO 2016 All righ
46、ts reserved ISO/TS 4949:2016(E) Table 1 Factors for alloying elements for steels in sub-group 2.2 Element Factor Co, Cr, Mn, Ni, Si, W 4 Al, Be, Cu, Mo, Nb, Pb, Ta, Ti, V, Zr 10 Ce, N, P, S 100 B 1 000 7.3.3 Alloy steels (except high speed steels) where the average content by mass of at least one al
47、lo ying element is 5 % (sub-gr oup 2.3) The coding shall comprise successively the following symbols. a) The letter X. b) A number being 100 the specified average percentage carbon content. Where the carbon content is not specified by a range the subcommittee responsible for the relevant product sta
48、ndard shall select a suitably representative value. NOTE To distinguish between two similar steel grades, the number indicating carbon content can be increased or decreased by one unit. c) Chemical symbols indicating the alloying elements that characterize the steel. The sequence of symbols shall be
49、 in decreasing order of the value of their content; where the values of contents are the same for two or more elements, the corresponding symbols shall be indicated in alphabetical order. d) Numbers indicating the values of contents of alloying elements. Each number represents the average percentage content of the element indicated rounded to the nearest integer. The numbers referring to the different elements shall be separated by hyphens. 7.3.4 High speed steel (sub-group 2.4) The coding shall comprise success
