ISO/DIS 437

Steel and cast iron -- Determination of total carbon content -- Combustion gravimetric method

Aciers et fontes -- Dosage du carbone total -- Méthode gravimétrique après combustion

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 437
ISO/TC 17/SC 1 Secretariat: JISC
Voting begins on: Voting terminates on:
2014-06-24 2014-09-24
Steel and cast iron — Determination of total carbon
content — Combustion gravimetric method

Aciers et fontes — Dosage du carbone total — Méthode gravimétrique après combustion

ICS: 77.080.01
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
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Reference number
NATIONAL REGULATIONS.
ISO/DIS 437:2014(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 2014
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ISO/DIS 437:2014(E)
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ii © ISO 2014 – All rights reserved
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ISO/CD 437
Contents Page

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

Introduction.........................................................................................................................................................v

1 Scope......................................................................................................................................................1

2 Normative references............................................................................................................................1

3 Principle.................................................................................................................................................1

4 Reagent...................................................................................................................................................1

5 Apparatus...............................................................................................................................................3

6 Sampling................................................................................................................................................5

7 Procedure...............................................................................................................................................5

7.1 Preparation of the apparatus ...............................................................................................................5

7.2 Test portion............................................................................................................................................5

7.3 Blank test ...............................................................................................................................................5

7.4 Combustion............................................................................................................................................5

7.5 Determination ........................................................................................................................................6

8 Expression of results............................................................................................................................6

9 Test report..............................................................................................................................................6

© ISO 2013 – All rights reserved iii
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ISO/CD 437
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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

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.

ISO 437 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 1, Methods of

determination of chemical composition.

This second edition cancels and replaces the first edition of which has been technically revised.

iv © ISO 2013 – All rights reserved
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ISO/CD 437
Introduction

The first edition of ISO 437 published in 1985 specified the use of asbestos, which is now known as a

carcinogenic substance. The main revised items of the second edition from the first edition are the replacements of

substances containing asbestos with substances free of asbestos. Some points have been also revised editorially

and/or technically in accordance with the updated ISO/IEC Directives, Part 2 and recent specifications in

International Standards prepared by ISO/TC 17/ SC1.
© ISO 2013 – All rights reserved v
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COMMITTEE DRAFT ISO/CD 437
1 Steel and cast iron—Determination of carbon—Combustion gravimetric
2 method
3 1 Scope

4 This International Standard specifies a gravimetric method for the determination of carbon in steel and cast

5 iron after combustion of the test portion in a current of oxygen.

6 The method is applicable to mass fractions of total carbon not less than 0,1 %.

8 2 Normative references

9 The following referenced documents are indispensable for the application of this document. For dated

10 references, only the edition cited applies. For undated references, the latest edition of the referenced

11 document (including any amendments) applies.

12 ISO 3696, Water for analytical laboratory use — Specification and test methods

13 ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical

14 composition
15 3 Principle

16 Combustion of a test portion at a high temperature (1 200 °C to 1 350 °C) in a current of pure oxygen, if

17 necessary in the presence of a flux and Conversion of carbon into carbon dioxide.

18 Absorption of the carbon dioxide carried by the current of oxygen in a carbon dioxide absorbent contained in a

19 weighed absorption bottle, and determination of the increase in mass.
21 4 Reagent

22 During the analysis, unless otherwise stated, use only reagents of recognised analytical grade and only grade

23 2 water as sspecified in ISO 3696.
24 4.1 Oxygen, minimum purity 99 % (volume fraction)
25 4.2 Magnesium perchlorate, Mg(CIO ) anhydrous
4 2,

26 WARNING — Contact between magnesium perchlorate and organic substances should be avoided

27 because of possible risk of explosion.
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ISO/CD 437
29 4.3 Fluxes, copper oxide, tin, pure iron, etc.

30 4.4 Iron, high purity quality containing less than 0,001 0 % mass fraction of carbon

31 4.5 Manganese dioxide or silver orthovanadate
32 Prepare as follows:
33 4.5.1 Manganese dioxide

34 When a chemically active grade is not available, it may be prepared as follows:

35 it may be prepared as follows (about 80 g of manganese dioxide is obtained):Dissolve 200 g of manganese(II)

36 sulphate tetrahydrate (MnSO4·4H2O) in 2,5 l of water in a 4 l beaker and add ammonium hydroxide for

37 making this solution clearly ammoniacal. Add 1 l of ammonium persulphate solution (225 g/l) freshly prepared

38 and bring the whole to boiling point. Continue boiling for 10 min and add ammonium hydroxide solution as

39 frequently as is necessary to maintain the solution ammoniacal. Allow the precipitate to settle.

40 If the supernatant liquid is not clear, or the precipitate does not settle quickly, add 50 ml to 100 ml of

41 ammonium persulphate solution and boil again for 10 min, keeping the solution constantly ammoniacal.

42 When precipitation appears to be complete, allow th
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