GOST R 51576-2000

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  ГОСТ Р 51576-2000

GOST R 51576−2000 Alloys and powders heat-resistant, corrosion-resistant, precision Nickel-based. Methods for determination of copper

GOST R 51576−2000

Group B39

STATE STANDARD OF THE RUSSIAN FEDERATION

ALLOYS AND POWDERS HEAT-RESISTANT, CORROSION-RESISTANT, PRECISION NICKEL-BASED

Methods for determination of copper

Heat-proof, corrosion-resistant, precision alloys and powders on the basis of nickel. Methods of copper determination

ISS 77.100.20*
AXTU 1700
____________________
* In the index «National standards», 2008
ISS 77.120. — Note the manufacturer’s database.

Date of introduction 2001−01−01

Preface

1 DEVELOPED AND SUBMITTED by the Technical Committee for standardization TC 145 «monitoring Methods of steel products"

2 ADOPTED AND put INTO EFFECT by the Resolution of Gosstandart of Russia from 23 March 2000 N 63 St

3 INTRODUCED FOR THE FIRST TIME

1 Scope

This standard specifies the extraction-photometric (at a mass fraction of copper from 0.005% to 0.1%) and atomic absorption (at a mass fraction of copper from 0.01% to 6.0%) methods for determination of copper in high-temperature, corrosion-resistant and precision alloys and powders on the basis of Nickel.

2 Normative references

The present standard features references to the following standards:

GOST 849−97* Nickel primary. Specifications
________________
* On the territory of the Russian Federation GOST 849−2008, here and hereafter. — Note the manufacturer’s database.

GOST 859−78* Copper. Brand
________________
* On the territory of the Russian Federation GOST 859−2001, and ssdes hereinafter. — Note the manufacturer’s database.

GOST 3118−77 hydrochloric Acid. Specifications

GOST 3760−79 Ammonia water. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 5457−75 Acetylene, dissolved and gaseous. Specifications

GOST 6552−80 orthophosphoric Acid. Specifications

GOST 8864−71 Sodium N, N-diethyldithiocarbamate 3-water. Specifications

GOST 10652−73 Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B). Specifications

GOST 11125−84 nitric Acid of high purity. Specifications

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 14262−78 sulphuric Acid of high purity. Specifications

GOST 24147−80 aqueous Ammonia of high purity. Specifications

GOST 28473−90 Iron, steel, ferroalloys, chromium and manganese metal. General requirements for methods of analysis

3 General requirements

General requirements for methods of analysis GOST 28473.

4 Extraction-photometric method for the determination of copper (0,005% to 0,1%)

4.1 the essence of the method

The method is based on the formation in ammonia solution (pH of 8.5−9.0) are colored yellow complex compounds of bivalent copper with sodium diethyldithiocarbamate, and extracted with chloroform. The influence of Nickel, chromium, molybdenum, cobalt, manganese, iron can be eliminated by adding citrate of ammonium and Trilon B.

4.2 Equipment, reagents and solutions

Spectrophotometer or photoelectrocolorimeter with all accessories for measurements in the visible region of the spectrum.

a pH meter.

The hydrochloric acid according to GOST 3118 or GOST 14261.

Nitric acid according to GOST 4461 or GOST 11125.

Nitric acid, diluted (1:1).

Sulfuric acid according to GOST 4204 or GOST 14262.

Sulfuric acid, dilute (1:1).

Orthophosphoric acid according to GOST 6552.

Ammonia water according to GOST 3760 or GOST 24147.

Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B) according to GOST 10652, a solution of 10 g/l: dissolve 10 g of Trilon B in the 70−80 cmof water when it is heated, cooled, made up to 1000 cmwater.

Sodium N, N-diethyldithiocarbamate 3-water according to GOST 8864.

Sodium N, N-diethyldithiocarbamate 3-hydrate solution of 1 g/DM; prepared immediately before use.

Sodium N, N-diethyldithiocarbamate 3-hydrate solution of 5 g/DM; prepared immediately before use.

Chloroform.

Ammonium citrate disodium, a solution of 250 g/DM, purified from impurities of heavy metals by the extraction of their complexes with sodium diethyldithiocarbamate in chloroform. In a separating funnel with a capacity of 500 cmis placed 250 cmof solution of citrate of ammonium, adding ammonia solution to pH of 9.0 by universal indicator paper, 25 cmof a solution of sodium diethyldithiocarbamate, 50 cmof chloroform and vigorously shaken for 2 min, the Chloroform layer discarded.

Copper grade M00b or M00k GOST 859.

Standard solutions of copper.

Solution a: 1 g of copper is placed in a beaker with a capacity of 250−300 cm, flow 20−25 cmof nitric acid (1:1), covered with a glass watch glass and dissolve the sample when heated. Add 30 cmof sulphuric acid (1:1), evaporated the solution prior to the allocation of steams of sulfuric acid, cooled, the walls of the beaker and watch glass is washed with water and again evaporated to fumes of sulfuric acid, cool. Salt is dissolved in 70−80 cmof water while heating, the solution was transferred to a volumetric flask with a capacity of 1 DM, cooled, made up to the mark with water and mix.

1 cmstandard solution contains 0.001 g of copper.

Solution B: 10 cmstandard solution And transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmstandard solution B contains 0.0001 g of copper.

Universal indicator boom

yeah, pH 1−10.

4.3 analysis

4.3.1 Preparation of test solution

The weight of the portion of the alloy is 0.25−1 g in accordance with table 1 were placed in a glass (or flask) with a capacity of 250−300 cm, 30 cm, pour themixture of hydrochloric and nitric acids (3:1 or 8:1), 5 cmof phosphoric acid, cover with watch glass and dissolve the sample in moderate heat.


Table 1

Pour 15 cmof sulphuric acid (1:1) solution and evaporated to release vapors of sulfuric acid, cool.

The walls of the beaker and watch glass is washed with water and evaporated the solution to release of sulfuric acid vapor. Salt is dissolved in 50−60 cmof water by heating, the solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

The solution is filtered over a dry filter medium density in a dry conical flask with a capacity of 100 cm, discarding the first portions of the filtrate.

4.3.2 Spectrophotometric assay procedure

Aliquot part of the solution was 10 cmwere placed in a glass with a capacity of 50−100 cm, pour 5 cmof ammonium citrate solution, 10 cmof Trilon B solution, mix and add ammonia solution to pH 8−9 by controlling pH on pH meter or universal indicator paper.

The solution was transferred to a separatory funnel with a capacity of 150−200 cm, top up with water to 60−70 cm, add 5 cmof a solution of sodium diethyldithiocarbamate, 10 cmof chloroform and extracted by vigorously shaking funnel for 2 min. Water and chloroform, the layers allowed to settle and decanted chloroform layer in a dry volumetric flask with a capacity of 25 cm, filtering it through dry cotton wool.

The separating funnel aqueous solution was added to 5 cmof chloroform and re-extracted for 2 min. After settling of the solution, the chloroform layer decanted into the same flask with a capacity of 25 cm, the solution is topped up to the mark with chloroform and mix.

Optical density of the solution measured immediately upon extraction on a spectrophotometer at a wavelength of 435 nm or photoelectrocolorimeter with a filter having a region of transmittance in the wavelength interval from 420 to 450 nm in a cuvette with the thickness of the light absorbing layer 2 see

As a comparison, using a solution of chloroform. Mass of copper find the calibration schedule, as amended by the control of

trying.

4.3.3 Construction of calibration curve

Six of cups (or flasks) with a capacity of 250−300 cmis placed a measured quantity of standard solution B copper 0,00; 0,50; 1,00; 1,50; 2,00; 2,50 cm, which corresponds to 0; 0,5·10; 1,0·10; 1,5·10; 2,0·10; 2,5·10g of copper.

All the glasses are poured at 30 cmof a mixture of hydrochloric and nitric acids (3:1 or 8:1), 5 cmof phosphoric acid, cover glasses, watch glasses and then act in accordance with 4.3.1 and 4.3.3.

From the values of absorbance of analyzed solutions is subtracted the value of optical density in the reference experiment. On the found values of optical density and corresponding mass of copper to build the calibration graph

IR.

4.4 Processing of results

4.4.1 Mass fraction of copper , %, is calculated by the formula

, (1)

where - the mass of copper, was found in the calibration schedule g;

 — the weight of the portion of alloy,

5 Atomic absorption method for the determination of copper (0.01% to 6,0%)

5.1 the essence of the method

The method is based on measurement at 324,8 nm of the absorption of resonance radiation by free atoms of copper, formed as a result of spraying the test solution in a flame air-acetylene.

5.2 the Instrument, reagents and solutions

Atomic absorption spectrophotometer.

Lamp with hollow cathode for the determination of copper.

Acetylene according to GOST 5457.

The compressor that supplies compressed air or compressed air.

The hydrochloric acid according to GOST 3118 or GOST 14261.

Nitric acid according to GOST 4461 or GOST 11125.

Nitric acid, diluted (1:1).

Sulfuric acid according to GOST 4204 or GOST 14262.

Sulfuric acid, dilute (1:1).

Orthophosphoric acid according to GOST 6552.

Orthophosphoric acid, dilute (1:1).

A mixture of hydrochloric and nitric acids: the three parts of muriatic acid mixed with one part of nitric acid.

Copper grade M00k and M00b according to the GOST 859.

Nickel brand N-0 GOST 849.

Standard solutions of copper.

Solution a: 1 g of copper is dissolved by heating in 20−30 cmof nitric acid (1:1). The solution was boiled to remove oxides of nitrogen, cooled, transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix.

1 cmstandard solution contains 0.001 g of copper.

Solution B: 10 cmstandard solution And placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmstandard solution B contains 0.0001 g of copper

.

5.3 analysis

5.3.1 Preparation of test solution

The weight of the alloy 0.1−0.5 g in accordance with table 2 were placed in a glass with a capacity of 250−300 cm, 30 cm, pour themixture of hydrochloric and nitric acids, 6 cmof sulphuric acid (1:1) and 6 cmof phosphoric acid (1:1) and dissolved by heating.


Table 2

The solution was evaporated until fumes of sulphuric acid and cooled. Salt is dissolved by heating to 30−40 cmof water and cooled. The solution was transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix. Aliquot part of the solution in accordance with table 1 was placed in a volumetric flask with a capacity of 100 cm, add 5 cmof sulphuric acid (1:1), made up to the mark with water and mix.

For the reference experiment in a beaker with a capacity of 250−300 cmpour all the reagents used in the analysis.

Allowed another dilution of solutions so that the concentration of copper was in the range corresponding to the straight-line segment calibration curve.

5.3.2 preparation of the device for measuring

The device is prepared to work in accordance with the attached instructions.

Set the spectrophotometer at a resonance line of 324,8 nm. After turning on gas supply and ignition of the burner spray water and set the device to zero.

5.3.3 Spectral analysis procedure

Is sprayed into the flame of the solution in the reference experiment, and then test solutions in order of increasing copper concentration to obtain stable readings for each solution.

Prior to introduction into the flame of each test solution is sprayed water to wash the system and check the zero point.

From the average value of the optical density of each of the tested solutions is subtracted the average value of optical density in the reference experiment.

Mass of copper found by the calibration schedule.

5.3.4 Construction of calibration graphs

5.3.4.1 Construction of calibration curve in mass fraction of copper from 0.01% to 0.1%

Seven of cups with a capacity of 250−300 cmis placed hinge is Nickel in the amount corresponding to the weight of alloy (table 2).

Six glasses poured successively 0,5; 1,0; 1,5; 2,0; 2,5 and 3,0 cmstandard solution B copper. The seventh glass is used for the reference experiment. All the glasses are poured at the 30−40 cmof a mixture of hydrochloric and nitric acids and then act in accordance with 5.3.1 and 5.3.3.

From the average of optical density of test solution subtract the mean value of optical density in the reference experiment.

On the found values of optical density and corresponding mass of copper to build the calibration graph.

5.3.4.2 Construction of calibration curve for the mass concentration of copper in excess of 0.1% to 6.0%

Six glasses with a capacity of 250−300 cmis placed hinge is Nickel in the amount corresponding to the weight of alloy (table 2).

In five glasses poured consistently 2,0; 4,0; 6,0; 8,0 and 10,0 cmstandard solution B copper. The sixth glass is used for the reference experiment.

All the glasses are poured at the 30−40 cmof a mixture of hydrochloric and nitric acids and then act in accordance with 5.3.1 and 5.3.3.

From the average of optical density of test solution subtract the mean value of optical density in the reference experiment.

On the found values of optical density and corresponding mass of copper to build the calibration graph.

5.4 processing of the results

5.4.1 Mass fraction of copper , %, is calculated by the formula

, (2)

where - the mass of copper, was found in the calibration schedule g;

- the weight of the portion of alloy,

Norms of accuracy and norms of accuracy control of determination of mass fraction of copper is given in table 3.


Table 3