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Ref. No.: ISO/R 629 - 1967 (E)
IS0
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
IS0 RECOMMEN DATION
R 629
CHEMICAL ANALYSIS OF
STEELS
DETERMINATION OF MANGANESE
(SPECTROPHOTOMETRIC METHOD)
1st EDITION
November 1967
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The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRIEF HISTORY
The IS0 Recommendation R 629, Chemical Analysis of Steels - Determination of Man-
ganese - (Spectrophotometric Method), was drawn up by Technical Committee ISO/TC 17,
Steel, the Secretariat of which is held by the British Standards Institution (BSI).
Work on this question by the Technical Committee began in 1955 and led, in 1965, to the
adoption of a Draft IS0 Recommendation.
W
In February 1966, this Draft IS0 Recommendation (No. 914) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial
nature, by the following Member Bodies:
Argentina Hungary Romania
Australia India Spain
Austria
Israel Sweden
Belgium Italy Switzerland
Brazil Japan Turkey
Canada Korea, Rep. of U.A.R.
Chile
Netherlands United Kingdom
Czechoslovakia New Zealand
U.S.A.
Denmark Norway
U.S.S.R.
France Poland Yugoslavia
Germany Republic of South Africa
One Member Body opposed the approval of the Draft:
Portugal
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council,
which decided, in November 1967, to accept it as an IS0 RECOMMENDATION.
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ISO/R 629-1967 (E)
IS0 Recommendation R 629 November 1967
CHEMICAL ANALYSIS OF STEELS
DETERMINATION OF MANGANESE
(SPECTROPHOTOMETRIC METHOD)
1. SCOPE
1.1 This IS0 Recommendation describes a spectrophotometric method for the determination of
manganese in steels.
1.2 The method is applicable to manganese contents between 0.01 and 4 %.
2. PRINCIPLE OF THE METHOD
After solution of the steel, the manganese is oxidized to the permanganate ion by sodium per-
iodate and determined spectrophotometrically.
3. REAGENTS*
Water free from organic matter. Bring to the boil demineralized water acidified with 10 ml
3.1
per litre of sulphuric acid (3.4), add several crystals of sodium periodate (3.2) and keep
boiling for 10 minutes.
3.2 Sodium periodate, pure for analysis.
3.3 Potassium permanganate, pure for analysis (purity over 99.5 %).
3.4 Sulphuric acid (d= 1.83 approximately).
3.5 Nitric acid (d= 1.40 approximately).
3.6 Perchloric acid (d= 1.67 approximately).
NOTE. - 60% perchloric acid (dx1.54 approximately) may also be used (loo0 ml of perchloric acid
dz1.67 are equivalent to 1270 ml of perchloric acid d=1.54).
Wherever necessary, the results should be cor-
* Verify by blank tests that the relevant reagents are free from manganese.
rected accordingly.
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ISO/R 629-1967 (E)
3.7 Hydrochloric acid (d= 1.19 approximately).
3.8 Sulphuric-phosphoric acid mixture. To 600 ml of water add in the following order, care-
fully and stirring at the same time, 100 ml of sulphuric acid (3.4) and 150 ml of phosphoric
acid (d=1.71); cool and dilute to 1000 ml with water.
3.9 Hydrogen peroxide, 100 volumes (30 %).
3.10 Sulphur dioxide.
3.11
Sodium periodate solution, 50 g per litre. Dissolve 50 g of sodium periodate (3.2) in 500 ml
of water and dilute to 1000 ml with water.
3.12 Standard manganese solution
3.12.1 Stock solution. Dissolve 2.877 g of potassium permanganate (3.3) in 500 ml of water,
and add 10 ml of sulphuric acid (3.4). Decolourize the solution with hydrogen peroxide
(3.9) or with a stream of sulphur dioxide (3.10). In the latter case, eliminate the excess
of reagent by boiling. Adjust the solution when cold to 1000 ml in a volumetric flask.
1 ml of the stock solution contains 1.00 mg of manganese.
3.12.2 Standard solution A. Take 100 ml of the stock solution and dilute to lo00 ml in a volu-
metric flask.
1 ml of standard solution A contains 0.1 mg of manganese.
3.12.3 Standard solution B. Take 250 ml of the standard solution A and dilute to 1000 ml in a
volumetric flask.
1 ml of standard solution B contains 0.025 mg of manganese.
4. APPARATUS
Ordinary laboratory equipment.
Spectrophotometer.
5. SAMPLING
In ac ordance with IS0 Re ommendation R 377, Selec ion and Preparation of Samples and Test
Pieces for Wrought Steel.
6. PROCEDURE
6.1 For manganese contents between 0.05 and 4 %
6.1.1 Test portion
1 f 0.001 g for assumed manganese contents between 0.05 and 2 %.
0.5 f 0.001 g for assumed manganese contents equal to or greater than 2%.
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ISO/R 629-1987 (E)
6.1.2 Plotting of calibration curve. Into a 250 ml conical flask introduce 1 g of pure iron free
from manganese, add 50 ml of sulphuric-phosphoric acid mixture (3.8) and heat gently
until effervescence ceases. When the attack is complete, oxidize with a few drops of
nitric acid (3.5) and add 20 ml of perchloric acid (3.6). * Evaporate until white per-
chloric acid fumes are given off and keep at this temperature for 10 minutes.
After cooling, take up with water, dilute to 70 to 80 ml and boil. If necessary, filter,
washing with hot water acidified with 2 ml of perchloric acid (3.6) per litre.
Collect the filtrate in a 100 ml volumetric flask and make up to volume with water.
This gives solution SI.
into a series of six 250 mi conical flasks
5 6
~-
ml of standard
15.0 20.0
solution A
containing ~ O I 0.20 1 0.50 ~ 1.00 1.50 2.00 mg of manganese
L
and corresponding to
for a test and
...