5949 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEXAYHAPOAHAR OPFAHW3ALMA NO CTAHAAPTW3AUWWORGANISATION INTERNATIONALE DE NORMALISATION Tool steels and bearing steels - Micrographic method for assessing the distribution of carbides using reference photomicrographs Aciers aoutils etaciersderoulement- Methode micrographique d'évaluation de la repartition des carbures a I'aide d'images-types First edition - 1983-12-15 SO 5949-1983 (E) UDC 669.14.018.25 : 620.186 Ref.No.ISO 5949-1983 (E) Descriptors : steels, tool steels, analysis methods, metallography, determination, carbides, comparison analysis, sampling. Price based on 9 pages Standardizatio Not for Resale Foreword ISo(the International Organization for Standardization)is a worldwide federation of national standards bodies (IsO member bodies). The work of developing International Standards is carried out through ISo technical committees. Every member body interested in a subject for whicha technical committee has been authorized has the right to be represented on that committee. International organizations; governmentai 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 member bodies for approval before their acceptance as International Standards by the Iso Council. International Standard ISO 5949 was developed by Technical Committee ISO/TC 17, Steel, and was circulated to the member bodies in September 1982. It has been approved by the member bodies of the following countries : Australia Ireland Portugal Austria Italy South Africa, Rep. of Belgium Japan Spain Czechoslovakia Kenya Sweden Egypt, Arab Rep. of Korea, Dem. P. Rep. of Tanzania France Korea,Rep.of Turkey Germany, F.R. Netherlands United Kingdom Hungary NewZealand USA India Norway Iran Poland No member body expressed disapproval of the document. ? International Organization for Standardization, 1983 Printed inSwitzerland Copyright International Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale ISO5949-1983(E) INTERNATIONAL STANDARD Tool steels and bearing steels - Micrographic method for assessing the distribution of carbides using reference photomicrographs 1 Scope and field of application 3.3 Each series is made up of 10 reference photomicrographs which represent the increasing levels ofcarbides.These This International Standard specifies the micrographic method photomicrographs are marked by the figures 0 to 9, the figures for assessing the distribution of carbides in tool and bearing increasing with the quantity of carbides. steels, with C levels between 0,1 % and 1,5 % and a total con- tentofalloyelementslessthanorequalto5%.Theuseofthis According to the series, these photomicrographs correspond to methodforothersteels shall besubjecttospecialagreement. field sizes of : 0,08 mm observed at a magnification of 1 000 for 2References series NA; ISo 683/17, Heat-treated steels, alloy steels and free-cutting 0,4 mm observed at a magnification of 200 for series NH; steels -- Part 17 : Ball and roller bearing steels. 0,8 mm observed at a magnification of 100 for series LE ISO 4957, Tool steels. and LD; 3.4 The characteristic number for the distribution of carbides 3 Principles of the method is.madeupofthesymbol oftheseriestakenforreferenceand the number of the photomicrograph corresponding to the field 3.1 The distribution of carbide is assessed by comparison observed. with the reference photomicrographs given in the plate in the annex. Sampling 3.2 The reference photomicrographs are divided into four main series1 according to shape, dimensions and the distribu- 4.1 Samples are generally taken from rounds, bars and wide tion of carbides : flats. Sampling shall be carried out so that the surface to be examined coincides with the direction of greatest elongation of series NA relating to the distribution of carbides at the