4948/1 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAR OPTAHM3AUMR NO CTAHAAPTM3AUWW+ORGANISATION INTERNATIONALE DE NORMALISATION Steels - Classification Part 1 : Classification of steels into unalloyed and alloy steels based on chemical composition Aciers -Classification -Partie1:Classification en aciers allies et en aciers non allies basee sur la composition chimique First edition - 1982-06-15 ISO 4948/1-1982 (E) UDC.669.14/.15 Ref. No. IS0 4948/1-1982 (E) Descriptors:stcels,unalloyed steels,alloy stecls,classifications,chemical composition. Price based on 2 pages Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (Iso member bodies). The work of developing Inter- national Standards is carried out through ISo technical committees.Every member body interested in a subject for which a technical committee has been set up 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. Draft International Standards adopted by the technical committees are circulated to the memberbodiesfor approval before theiracceptance as International Standards by the ISO Council. Standard ISO 4948/1 was developed by Technical Committee International ISo/TC 17, Steel, and was circulated to the member bodies in January 1981. It has been approved bythe member bodies of the following countries : Australia Iran Poland Austria Iraq Romania Belgium Italy South Africa, Rep. of Bulgaria Japan Spain Canada Korea, Dem. P. Rep. of Sweden China Korea, Rep.of Switzerland France Netherlands Venezuela Hungary New Zealand India Norway The member bodies of the foillowing countries expressed disapproval of the document on technical grounds : Czechoslovakia United Kingdom USA @InternationalOrganization forStandardization,1982 Printed in Switzerland ISO4948/1-1982 (E) INTERNATIONALSTANDARD Steels s - Classification Part 1 : Classification of steels into unalloyed and alloy steels based on chemical composition Scope andfieldofapplication 3.1.1.1 Where a minimum value or range is specified for the ladle analysis of the elementsgiven in thetable,the minimum This part of ISO 4948 lays down a classification of steels into value shall be taken for classification. unalloyed and alloy steelsbasedon chemical composition. according to main quality classes and main property or applica- 3.1.1.2 Where the manganese content of the ladle analysis is tion characteristics. specified as a maximum value only, this maximum value shall be taken for classification. 2 Definition For the purpose of this International Standard, the following 3.1.1.3 3Wherefor elements otherthanmanganesea max- definition applies : imum value only is specified for the ladle analysis, a value of 0,7 times this maximum value shall be taken for classification. steel : A material with iron as the predominant element, having a carbon content generally less than 2,o % and containing other elements.A limited numberof chromium steels may have 3.1.1.4 Where there is no standard or specification or ordercd more than 2,o % carbon, but 2,o % is the usual dividing line composition, the ladle analysis reported by the manufacturer between teel and cast iron. shall be taken for classification. The results of product analysis may deviate from those of the 3 Classification standard. Where the product analysis indicates a value which 3.1 Steels are classified as (e unalloyed steels; be separately and reliably substantiated. alloy steels. b) 3.1.2 Unalloyed steels are those in which for all elements 3.1.1 From the different values given for the chemical com- listed in the table the percentage of each element taken in ac- position of the steel. the following (3.1.1.1 to 3.1.1.4) shall be cordance with 3.1.1 is less than the boundary values given for taken for classifying the steel as alloyed or unalloyed. the relevant e