GOST 12356-81

• gost-12356-81.pdf (350.72 KiB)
  ГОСТ 12356-81

GOST 12356−81 Steel alloyed and high alloy. Methods for the determination of titanium (with Amendments No. 1, 2)

GOST 12356−81

Group B39

INTERSTATE STANDARD

STEEL ALLOYED AND HIGH-ALLOYED

Methods for determination of titanium

Steels alloyed and highalloyed. Methods of the determination of titanium

ISS 77.080.20

Date of introduction 1981−07−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR

DEVELOPERS

N. P. Liakishev, S. M. Novokshenov, V. T. Ababkov, M. S. Dimova, D. V. Khromov, T. F., Rybina, I. F. Medelyan, E. I. Vasil’eva, O. I. Putintseva

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 07.04.81 N 1867

3. The standard fully complies ST SEV 965−78

4. REPLACE GOST 12356−66 in part of sec. 2−6

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (ICS 11−12−94)

7. EDITION (July 2005) with Amendments No. 1, 2 approved in December 1985, December 1990 (IUS 4−86, 3−91)


This standard specifies the extraction-photometric method for the determination of titanium (with a mass fraction of titanium from 0.005 to 0.3%), a photometric method (when the mass fraction of titanium from 0.01 to 3.5%) in the alloy and high-alloy steels.

The standard fully complies ST SEV 965−78.

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 28473.

(Changed edition, Rev. N 2).

2. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF TITANIUM IN STEELS CONTAINING NOT MORE THAN 1% OF NIOBIUM AND NOT MORE THAN 1% OF TUNGSTEN

2.1. The essence of the method

The method is based on formation of yellow colored coordination compounds of titanium with diantipyrylmethane, its extraction with chloroform and measuring the absorption of the extract at a wavelength of 395 nm or at 410−430 nm (in the presence of niobium).

Mass of titanium is 50 cmextract of 10−150 µg. Iron (III) and vanadium (V) is reduced with ascorbic acid.

(Changed edition, Rev. N 2).

2.2. Equipment and reagents

Spectrophotometer or photoelectrocolorimeter.

Hydrochloric acid according to GOST 3118 or GOST 14261 and diluted 1:1, 1:6, 1:9, 1:100.

Sulfuric acid according to GOST 4204 or GOST 14262 and diluted 1:2, 1:4, 1:5.

Ammonia water according to GOST 3760.

Nitric acid according to GOST 4461 or GOST 11125.

Ascorbic acid solution 100 g/lfreshly prepared.

Universal indicator paper.

Hydrogen peroxide according to GOST 10929.

Potassium preservatory according to GOST 7172.

Diantipyrylmethane, a solution of 4 g/DM, freshly prepared in hydrochloric acid 1:6.

Chloroform according to GOST 20015.

Tin metal granules.

Tin chloride on the other 6−09−5393−88, solution: 200 g of tin chloride dissolved in 145 cmhot hydrochloric acid. The solution was cooled, top up with water to a volume of 1 DMand add a few granules of tin, a freshly prepared solution.

Titanium metal according to GOST 19807.

Titanium dioxide.

Titanium sulphate, standard solutions A and B.

Solution a: 0,1668 g svezhepriobretennoy at 1000 °C the titanium dioxide is placed in a platinum or quartz Cup and fused with 3−5 g of potassium peacemaking at 800−850 °C. After cooling the melt is dissolved in 400 cmof sulphuric acid (1:5) glass with a capacity of 600 cmand left for 12 h at room temperature. The solution was filtered through a filter «white ribbon» in a volumetric flask with a capacity of 1 DM, the filter was washed 3−4 times with sulfuric acid (1:5). The solution was topped to the mark with sulphuric acid (1:5) and stirred.

Set the mass concentration of solution A: 100 cmstandard solution of titanium sulfate was placed in a beaker with a capacity of 250−300 cm, poured with stirring a solution of ammonia to pH 8−9 by universal indicator, and then an excess of 3−5 cm. The solution with the precipitated sludge is heated to boiling and the precipitate was filtered off on filter «white ribbon». Filter the precipitate was washed 3−4 times with warm water containing 10 cmof ammonia solution in 1 DMof water, is placed in a preheated to constant mass and weighed platinum crucible, dried, incinerated and calcined at 1000−1100°C to constant weight. The crucible with residue was cooled in a desiccator and weighed.

Simultaneously conduct control experience for contamination of reagents.

The mass concentration of sulfate solution (titanium), expressed in g/cmtitanium, calculated by the formula

where is the mass of the crucible with the precipitate of titanium dioxide, g;

 — weight of crucible without precipitate titanium dioxide, g;

 — the mass of the crucible with the sediment in a control experiment, g;

 — weight of crucible without the sediment in a control experiment, g;

0,5996 — the ratio of titanium dioxide to titanium;

 — the volume of sulfate solution of titanium, taken for installation of the mass concentration, cm.

Preparation of a standard solution And may be of metallic titanium. For this 0.1 g of titanium metal is placed in a beaker with a capacity of 250−300 cm, flow 50 cmof sulphuric acid (1:2) and dissolved by heating. Then to the solution was added dropwise nitric acid to bleaching it and evaporated until the appearance of dense sulphuric acid fumes. The solution was cooled, carefully wash off the side of the Cup with water and again evaporated to the appearance of sulphuric acid fumes. After cooling, the solution is transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with sulphuric acid (1:5) and stirred. 1 cmof the solution contains 0.0001 g of titanium.

Solution B (prepared immediately before use): 100 cmsolution And transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with sulphuric acid (1:5) and stirred; prepared immediately before use.

1 cmof solution B contains 0,00001 g of titanium.

(Changed edition, Rev. N 1, 2).

2.3. Analysis

2.3.1. The analyzed sample is dissolved in one of three ways.

Method 1. The portion of steel in accordance with table.1 is placed in a quartz crucible with a capacity of 100−150 cm, covered with a quartz cover and is fused with 5−10 g peacemaking potassium at 700 °C. the Cooled melt is dissolved in 20 cmof hydrochloric acid (1:9).

Table 1

Method 2. The portion of steel in accordance with table.1 is placed in a beaker with a capacity of 100−150 cm, flow 10 cmof hydrochloric acid (1:1) and dissolved by heating, adding dropwise a solution of hydrogen peroxide. After complete dissolution of the sample the excess hydrogen peroxide is removed by boiling the solution.

Method 3. The portion of steel in accordance with table.1 is placed in a beaker with a capacity of 100−150 cm, dissolved by heating in 30 cmof hydrochloric acid and 5−7 cmof nitric acid, priliva her dropwise. Then add 10 cmsulphuric acid (1:4) and the solution was evaporated until the appearance of sulphuric acid fumes. The contents of the beaker cooled, poured 20 cmof hydrochloric acid (1:9) and heated to dissolve the salts.

Allowed other methods of dissolution, which provides a complete decomposition of the sample and do not require changes in subsequent stages of the analysis.

The resulting solution was filtered through a filter «white ribbon» (primary filtrate), wash the filter twice with hydrochloric acid (1:100) and twice with water. The filter with precipitate was placed in a quartz crucible, dried, incinerated, and calcined at 600−700 °C and fused with 1 g of potassium peacemaking. The melt is cooled, dissolved by heating in 20−30 cmof hydrochloric acid (1:9) and the solution filtered through the filter «white ribbon». The filter with the sediment is discarded and the filtrate obtained is attached to the main filtrate. The combined filtrates evaporated to a volume of 15−20 cm.

When the mass fraction of titanium from 0.005 to 0.15% of the entire solution transferred to a separatory funnel with a capacity of 100 cm, wall washing Cup 15 cmof hydrochloric acid (1:9).

When the mass fraction of titanium from 0.015 to 0.3% solution transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with hydrochloric acid 1:9 and stirred. Aliquot part of the solution is equal to 20 cm, placed in a separatory funnel with a capacity of 100 cm, flow 10 cmof hydrochloric acid (1:9), 5 cmof a solution of ascorbic acid and the solution was stirred. After 3 min in the separating funnel is poured 10 cmof the solution diantipyrylmethane and stirred. After 30 min, pour 5 cmof a solution of chloride of tin, mix and add 20 cmof chloroform.

Separatory funnel shaken for 1 min and after separation of the layers the organic layer decanted into a volumetric flask with a capacity of 50 cm. The extraction is repeated two times, each time adding 5 cmof chloroform. The organic layers are collected in the same volumetric flask with a capacity of 50 cm. The extract in the flask topped up to the mark with chloroform, stirred and filtered through a dry filter into a dry flask, which is stoppered. After 15 min measure the optical density of the colored extract on a spectrophotometer at a wavelength of 395 nm or photoelectrocolorimeter with a filter having maximum transmission in the wavelength range of 390−405 nm. The thickness of the absorbing layer of the cell is chosen so to obtain a value of optical density within the linear part of calibration curve.

As a solution the comparison used the chloroform.

Simultaneously with the execution of the analysis carried out control experience for contamination of reagents.

From the mean values of absorbance of each test solution subtract the mean value of optical density in the reference experiment.

Weight titanium find for the calibration schedule.

(Changed edition, Rev. N 1, 2).

2.3.2. Construction of calibration curve

In seven separating funnels with a capacity of 100 cmis administered at 20 cmof a hydrochloric acid solution (1:9) and six of them successively poured 1,0; 2,0; 4,0; 8,0; 12,0; 15,0 cmstandard solution B titanium. In separating funnels, add 5 cmof a solution of ascorbic acid and after 3 min add 10 cmof a solution diantipyrylmethane. Further analysis is carried out as specified in clause 2.3.1. When measuring light absorption in a solution of comparison, using the seventh extract in separating funnel, containing no titanium.

According to the obtained values of optical density and the corresponding mass of titanium is to build a calibration curve.

(Changed edition, Rev. N 2).

2.4. Processing of the results

2.4.1. Mass fraction of titanium () in percent is calculated by the formula

where is the mass of titanium in the sample was found in the calibration schedule g;

the weight of steel, suitable aliquote part of the solution,

(Changed edition, Rev. N 1).

3. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF TITANIUM

3.1. The essence of the method

The method is based on formation of yellow colored coordination compounds of titanium with diantipyrylmethane in hydrochloric acid medium and measuring the light absorption of the resulting solution at a wavelength of 395 nm. For the mass concentration of titanium to 0.1% mass fraction of tungsten in the sample must not exceed 1.5%.

Iron (III) and vanadium (V) is reduced with ascorbic acid. Tungsten and niobium complexes, respectively, phosphoric and tartaric acids.

(Changed edition, Rev. N 2).

3.2. Equipment and reagents

Spectrophotometer or photoelectrocolorimeter.

Hydrochloric acid according to GOST 3118 or GOST 14261 and diluted 1:1, 1:9, 1:100.

Sulfuric acid according to GOST 4204, diluted 1:1 and 1:2.

Nitric acid according to GOST 4461 or GOST 11125.

Orthophosphoric acid.

Tartaric acid according to GOST 5817, a solution with a mass concentration of 20 g/DM.

Ascorbic acid solution 100 g/l, freshly prepared.

Ammonia water according to GOST 3760.

Potassium preservatory according to GOST 7172.

Diantipyrylmethane, a solution of 4 g/DM, freshly prepared in hydrochloric acid (1:6).

Radio engineering carbonyl iron according to GOST 13610 or GSO-1, iron net type 008 ZHR.

Universal indicator paper.

Titanium metal according to GOST 19807.

Niobium sulfate, a solution with a concentration of 0.001 g/cmprepared one of the following ways:

0.1 g of niobium metal is placed in a platinum Cup, add 5 cmhydrofluoric acid and nitric acid drop by drop until complete dissolution of the sample. Then to the solution add 10 cmsulphuric acid and evaporated to fumes of sulfuric acid. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with sulphuric acid (1:2) and stirred.

0.1 g of niobium metal is placed in a flask or in a beaker with a capacity of 100−150 cm, add 2−3 cmof nitric acid and 40 cmof sulfuric acid and dissolved by heating. After complete dissolution of the sample solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

Standard solutions of titanium prepared as described in step 2.2.

3.3. Analysis

3.3.1. The portion of steel in accordance with table.2 is placed in a beaker with a capacity of 100−150 cmand dissolved by heating in 30 cmof hydrochloric acid and 5−7 cmof nitric acid, priliva her dropwise.

Table 2

Allowed other ways of dissolution of batches of steel that guarantees complete decomposition of the sample and does not require changes in the further stage of the analysis.

The contents of the beaker cooled, poured 15 cmof sulphuric acid (1:1), 2−3 cmof phosphoric acid (if the steel contains tungsten) and evaporated to the appearance of sulphuric acid fumes. The glass solution was cooled, poured 15 cmof a solution of tartaric acid (if the steel contains niobium and tantalum) and dissolve the salt in 20 cmof hydrochloric acid (1:9) when heated.

The solution was filtered through a filter «white ribbon» (primary filtrate) and washed the filter twice with hydrochloric acid (1:100) and twice with water. The filter with precipitate was placed in a crucible, dried, incinerated, and calcined at 600−700 °C and fused with 1 g of potassium peacemaking. The smelt is cooled and dissolved by heating in 20−30 cmof hydrochloric acid (1:9).

The resulting solution was attached to the main filtrate, transferred to a volumetric flask in accordance with table.2, made up to the mark with hydrochloric acid (1:9) and stirred. Part of the solution is filtered over a dry filter, discarding first portion of filtrate. In two volumetric flasks with a capacity of 100 cmis placed aliquote part of the solution in accordance with the table.2. To each flask add 5 cmof ascorbic acid solution, mix. After 5 min, add 15 cmof hydrochloric acid (1:1) and in one of the flasks poured 10 cmof the solution diantipyrylmethane. The solutions in flasks topped up to the mark with water and mix.

45−50 min measure the optical density of the obtained solutions on the spectrophotometer at a wavelength of 395 nm or photoelectrocolorimeter with a filter having maximum transmission in the wavelength range of 390−405 nm. The thickness of the light absorbing layer of the cell is chosen so to obtain a value of optical density within the linear part of calibration curve.

In the analysis of niobium-containing steels in absorbance measured in the wavelength range of 410−430 nm.

As a solution comparison, using aliquot part of a solution containing all the reagents except diantipyrylmethane.

Simultaneously with the execution of the analysis carried out control experience for contamination of reagents.

From the mean values of absorbance of each test solution subtract the mean value of optical density in the reference experiment.

Weight titanium find for the calibration schedule.

3.3.2. Construction of calibration curve

Seven glasses of a capacity of 100−150 cmis placed carbonyl iron and a solution of niobium in amounts corresponding to their content in the analyzed sample or sample steel is similar in composition to the analyzed and do not contain titanium. Six of them successively poured 1,0; 2,0; 4,0; 6,0; 8,0 and 10,0 cmstandard solution And titanium. The seventh glass is used for the reference experiment. Further analysis is carried out as described in section 3.3.1.

The capacity of volumetric flasks of 100 cm, the volume aliquote part of 10.0 cm. When measuring light absorption as a solution comparison solution is used in the seventh glass not containing titanium. According to the obtained values of optical density and the corresponding mass of titanium is to build a calibration curve.

3.2−3.3.2. (Changed edition, Rev. N 1, 2).

3.4. Processing of the results

3.4.1. Mass fraction of titanium in percent is calculated by the formula

where is the mass of titanium in the sample was found in the calibration schedule g;

the weight of steel, suitable aliquote part of the solution,

(Changed edition, Rev. N 1).

3.4.2. Norms of accuracy and norms control the accuracy of determining the mass fraction of titanium is given in table.3.

Table 3

(Changed edition, Rev. N 2).