ISO/DIS 4968

Steel -- Macrographic examination by sulfur print (Baumann method)

Acier -- Examen macrographique par empreinte au soufre (méthode Baumann)

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 4968
ISO/TC 17/SC 7 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2020-03-11 2020-06-03
Steel — Macrographic examination by sulfur print
(Baumann method)
Acier — Examen macrographique par empreinte au soufre (méthode Baumann)
ICS: 77.040.99
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 4968:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
---------------------- Page: 1 ----------------------
ISO/DIS 4968:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 4968:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope and field of application ................................................................................................................................................................. 1

2 General ............................................................................................................................................................................................................................ 1

3 Principle and aim of the test .................................................................................................................................................................... 1

4 Test paper and reagents ............................................................................................................................................................................... 2

4.1 Photographic paper ............................................................................................................................................................................ 2

4.2 Reagents........................................................................................................................................................................................................ 2

4.3 Fixing solution ......................................................................................................................................................................................... 2

5 Test piece ...................................................................................................................................................................................................................... 2

5.1 Sampling ....................................................................................................................................................................................................... 2

5.2 Machining .................................................................................................................................................................................................... 3

6 Procedure..................................................................................................................................................................................................................... 3

7 Test report ................................................................................................................................................................................................................... 4

Annex A (Informative) Classification of sulphur print test results ....................................................................................... 5

© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/DIS 4968:2020(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 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 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. 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. 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 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 received. 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

The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 7, Methods of testing

(other than mechanical tests and chemical analysis).
iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
DRAFT INTERNATIONAL STANDARD ISO/DIS 4968:2020(E)
Steel — Macrographic examination by sulfur print
(Baumann method)
1 Scope and field of application

This International Standard specifies a method (Baumann) for the macrographic examination of steel

by means of contact printing using silver salts and acid.

The method is applicable to steels of which the sulphur content is less than 0,40%. This method may

also be applied to cast irons.
2 General

2.1 The sulphur print test is essentially a qualitative test. It is inadvisable to assess the sulphur content

of a given steel merely on the basis of its sulphur print.

2.2 Experience shows that the degree of darkening of the photo-sensitive emulsion is not always

in proportion to the quantity of sulphides present in the metal. Certain factors may influence the

macrographic attack to a greater or lesser extent; as examples, the following may be quoted:

— the chemical composition of the steel: the presence of certain elements modifies the type and shape

of the sulphides and consequently the appearance of the image obtained, for example concentrations

of titanium greater than 0,1 % give prints which do not reveal sulphides;

— the surface condition of the sample: the presence of surface cold working may alter the image

obtained;
— the sensitivity of the photographic paper.

2.3 The use of the test, and the conditions for interpreting the results observed, depend on the

particular case: details are laid down in product standards or shall be subject to special agreement.

3 Principle and aim of the test

3.1 The aim of macrographic examination by sulphur printing is to detect, by printing on photo-

sensitive papers previously soaked in acid, the position of areas containing sulphur inclusions found in

the metal in various chemical forms and with various shapes: iron sulphide, manganese sulphides, mixed

sulphides, oxy-sulphides etc.

Note 1 to entry The photographic paper may be replaced by a flat film. The positive and transparent prints

obtained from the flat film may be used directly to produce negative proofs.

3.2 The distribution of the sulphur-rich areas is revealed by the local release of hydrogen sulphide,

causing darkening of the sensitive emulsion due to the chemical conversion of the silver halides to silver

sulphide.
3.3 By examining the distribution and size of the sulph
...