GOST 22536.10-88

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  ГОСТ 22536.10-88

GOST 22536.10−88 carbon Steel and unalloyed cast iron. Methods for determination of aluminium

GOST 22536.10−88

Group B09

STATE STANDARD OF THE USSR

CARBON STEEL AND UNALLOYED CAST IRON

Methods for determination of aluminium

Carbon steel and unalloyed cast iron.
Methods for determination of aluminium

AXTU 0809

Valid from 01.01.90
to 01.07.95*
______________________________
* Expiration removed
Protocol N 4−93 inter-state Council
for standardization, Metrology and certification.
(IUS N 4, 1994). — Note The Code.

INFORMATION DATA

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

PERFORMERS

D. K. Nesterov, PhD. tech. Sciences; S. I. Rudyuk, PhD. tech. Sciences; S. V. Spirina, PhD. chem. Sciences (head of subject); V. F. Kovalenko, PhD. tech. science; N. N. Gritsenko, PhD. chem. Sciences; M. A. Moses; L. I. birch

2. APPROVED AND put INTO EFFECT by decision of the USSR State Committee for standards from 25.08.88 N 3018

3. REPLACE GOST 22536.10−77

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard establishes photometric (at a mass fraction of aluminum 0,005−0,12%) and atomic absorption (at a mass fraction of aluminum of 0.05−0.12%) methods for determination of aluminium in carbon steel and unalloyed cast iron.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 22536.0−87.

1.2. The error of the result of the analysis (under confidence probability =0,95) does not exceed the limit given in table. 1, when the conditions are met:

the discrepancy between the results of two (three) parallel dimensions should not exceed (with a confidence probability =0,95) of the values given in table. 1;

played in the standard sample, the value of the mass fraction of aluminum must not vary from certified more than acceptable (at a confidence level =0,85) the value given in table. 1.

If any of the above conditions, a second measurement of the mass fraction of aluminium. If in repeated measurements the precision requirement of the results are not met, the results of the analysis recognize the incorrect measurements cease to identify and eliminate the causes of violation of the normal course of analysis.

The divergence of the two middle results of an analysis performed under different conditions (for example, when the control intralaboratory reproducibility) shall not exceed (at p = 0.95) values are given in table. 1.

Table 1

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF TOTAL ALUMINIUM

2.1. The essence of the method

The method is based on formation of colored complex compounds of aluminum with alumininum (=530 nm) at pH 4.7 or 5.1 or with chromazurol (=620 nm) in the presence of polyvinyl alcohol at a pH of 5.8 to 6.7.

The interfering influence of iron is removed by addition of ascorbic and thioglycolic acids.

Vanadium does not interfere with the determination of aluminum if its mass fraction does not exceed a mass fraction of aluminum three times. In another case, the influence of vanadium take into account the introduction of it solutions to build the calibration curve.

Titanium does not affect the determination of aluminum if its mass fraction is three times less than the mass fraction of aluminum. In another case it is separated together with iron, manganese, copper and chromium with sodium hydroxide in the presence of zinc chloride and boric acid.

2.2. Determination of aluminum with alumininum

2.2.1. Equipment and reagents

Spectrophotometer or photoelectrocolorimeter

a pH meter.

Hydrochloric acid by the GOST 3118−77 or GOST 14261−77 and diluted 1:1, 1:6, 1:20.

Nitric acid GOST 4461−77 or GOST 11125−84.

Sulfuric acid GOST 4204−77 or GOST 14262−78 diluted 1:1 and 1:20.

Hydrofluoric acid according to GOST 10484−78.

Ascorbic acid, a solution with a mass concentration of 50 g/DM, good for one day.

Thioglycolic acid, a solution with a mass concentration of 50 g/DM.

Acids mixture: mix equal volumes of solutions of ascorbic and thioglycolic acids.

Ammonia water according to GOST 3760−79 and diluted 1:1 and 1:20.

Benzoic acid, an alcoholic solution with a mass concentration of 100 g/DM.

Boric acid according to GOST 9656−75.

Carbonyl iron brand PS according to GOST 13610−79, with a mass fraction of aluminum of not more than 0.001% high purity, or grade.

Gelatin food according to GOST 11293−78. The solution is prepared as follows: 5 g of gelatin was dissolved in 500−600 cmof warm water, cooled, the volume was adjusted to 1 DMwith water and stirred.

Rectified ethyl alcohol according to GOST 5962−67 or GOST 18300−87.

Sodium carbonate according to GOST 83−79.

Sodium hydroxide according to GOST 4328−77, a solution with a mass concentration of 200 g/DM, is stored in a container made of polyethylene.

Zinc chloride according to GOST 4529−78 solution with a mass concentration of 100 g/DM; 100 g zinc chloride dissolved in water containing 10 cmof hydrochloric acid, transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix.

Aluminum, compound the solution with a mass concentration of 0.33 g/l500 g ammonium acetate and dissolve in 1 DMof warm water and poured 80 cm,of acetic acid; 1 g aluminon dissolved in 50 cmof water containing 2−3 drops of ammonia (1:20), poured 20 cmof the alcoholic solution of benzoic acid; all the solutions were poured water and bring volume to 3 DM, mixed and filtered. The solution can be used 2−3 days after cooking for 3 months.

Sodium acetate 3-water according to GOST 199−78.

Ammonium acetate according to GOST 3117−78.

Acetic acid according to GOST 18270−72 or GOST 61−75.

Buffer solution pH 5: 13.6 g sodium acetate dissolved in 200 cmof water. The solution is filtered, add 2 cmof acetic acid, add water to 1 DMand stirred.

Aluminium GOST 11069−74, brand А999, A995 or A97.

A standard solution of aluminum: 0,1000 g of aluminum is placed in a beaker with a capacity of 250−300 cm, 30 cm, pour thehydrochloric acid (1:1) and dissolved by heating. Add a few drops of nitric acid (3−4) until the termination of foaming and boil to remove oxides of nitrogen. Add 100−150 cmof hot water and heated to dissolve the salts. The solution was cooled, transferred to a volumetric flask with a capacity of 1 DM, add 30 cmof hydrochloric acid, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of aluminum.

Vanadium pentoxide, OS. h

The vanadium solution with the mass concentration of 0.0001 g/DM: 1,7851 g of vanadium pentoxide were placed in a glass, pour 50 cmof the sulphuric acid, heated to dissolve the sample, gently add 5 cmof nitric acid, evaporated to the appearance of sulphuric acid fumes. The solution was cooled, added to 200−250 cmof water, stirred, filtered through a filter of medium density in a volumetric flask with a capacity of 1 DM, the filter washed with warm water, collecting the wash liquid in the same flask. The solution was poured 100 cmof sulphuric acid (1:1). The solution was cooled, made up to the mark with water and mix.

Phenolphthalein for NTD, solution in ethyl alcohol with a mass

concentration 10 g/DM.

2.2.2. Analysis

2.2.2.1. A portion of the sample mass depending on the mass fraction of aluminium in steel or cast iron in accordance with table. 2 is placed in a beaker with a capacity of 200 cm, flow 20−30 cmof hydrochloric acid (1:1) and dissolved by heating. After dissolution of the sample are added dropwise nitric acid until the termination of foaming and 3−5 drops in excess. The solution was evaporated to dryness. To the dry residue add 10 cmof hydrochloric acid and again evaporated to dryness.

Table 2

Treatment of dry residue with hydrochloric acid repeated.

After cooling, add 10 cmof hydrochloric acid and heated to dissolve the salts. To the solution was added 30−40 cmof hot water and filtered off insoluble precipitate on the filter medium density, containing a little filter-paper pulp. Precipitate was washed 2−3 times with hot hydrochloric acid (1:20) and 2−3 times with hot water. The filtrate is saved.

The filter with precipitate was placed in a platinum crucible, dried and incinerated at 600 °C. the Residue in the crucible is moistened with 2−3 drops of water, add 2−3 drops of sulfuric acid (1:1), 3−5 cmhydrofluoric acid and cautiously evaporated to remove vapors of sulfuric acid. To the dry residue in the crucible add 1 g of anhydrous sodium carbonate and fused at 1000 °C for 10−15 min.

The smelt is leached in 20−30 cmof hydrochloric acid (1:20). The resulting solution was filtered and added to the main filtrate. The combined solution is evaporated to 50−60 cmand transferred to volumetric flask with a capacity of 100 cm. The solution was topped to the mark with water and mix.

If the analyzed sample contains titanium, then it is separated with sodium hydroxide. This combined solution is evaporated to a volume of 15−20 cm, add 5 cmof a solution of zinc chloride and 0.7 g of boric acid. The contents of the Cup are heated.

The hot solution carefully in small portions at careful hashing pour in a volumetric flask with a capacity of 100 cmcontaining the hot sodium hydroxide solution with a mass concentration of 200 g/DMin the amount of 30−40 cm, cooled, made up to the mark with water and mix. After settling the solution is filtered through a dry filter, the average density in the dry quartz or Teflon beaker, discarding the first portion of the filter.

rata.

2.2.2.2. In a volumetric flask with a capacity of 100 cmis taken aliquot part of the solution, depending on the mass fraction of aluminium in the sample in accordance with table. 1, pour 2−5 cmof a solution of ascorbic acid or mixture of ascorbic and thioglycolic acid, mix and leave for 3−5 minutes Then pour 10 cmof buffer solution, mix, add 8 cmof the composite solution aluminon, 3 cmgelatin solution, made up to the mark with buffer solution and stirred.

In the case of separation of aluminium from titanium, aliquot part of the alkaline solution in accordance with the table. 2 placed in a volumetric flask with a capacity of 100 cm, add 1−2 drops of phenolphthalein, and neutralize 12−15 drops of hydrochloric acid (1:1) until the color indicator and add an excess of 1 cmof hydrochloric acid (1:6), add 2cmof a solution of ascorbic acid or mixture of ascorbic and thioglycolic acid, mix and leave for 3−5 minutes Then pour 10 cmof buffer solution, mix, add 8 cmof the composite solution aluminon, 3 cmgelatin solution, made up to the mark with buffer solution and stirred.

The optical density of the solutions measured after 30 min in the spectrophotometer at a wavelength =530 nm or photoelectrocolorimeter with a green filter having a transmission region 530−540 nm. Solution comparison is the solution of the reference experiment. To prepare the solution in the reference experiment in a glass put a suspension of carbonyl iron, corresponding to the linkage of samples and then conduct the analysis as given in PP.2.2.2.1 and 2.2.2.2.

The analysis results calculated by a calibration chart or by comparison with a standard sample similar in composition to the sample and carried through all the stages of an

Aliza.

2.3. Determination of aluminum chromazurol

2.3.1. Equipment and reagents

Equipment and reagents according to claim 2.2.1 with additions:

Sodium hydroxide according to GOST 4328−77, a solution with a mass concentration of 50 g/DM, stored in a plastic container.

The polyvinyl alcohol GOST 10779−78, a solution with a mass concentration of 40 g/DM.

Buffer solution with a pH of (7,1±0,1): 274 g of ammonium acetate and 109 g of sodium acetate 3-water is dissolved in 600 cmof water, filter, add water to 1 DMand stirred.

The solution was stored in a plastic container.

Urea according to GOST 6691−77, a solution with a mass concentration of 15 g/DM; prepare before use.

Chromazurol , the solution with a mass concentration of 1 g/DM: 1 g of chromazurol placed in a beaker, moistened with water and dissolved in 6 cm.of nitric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 1 DMcontaining 500 cmof ethyl alcohol and 200 cmof water, add 50 cmof a solution of urea and top up with water to the mark. The solution to fit the application within two n

Edel.

2.3.2. Analysis

2.3.2.1. Dissolution probie the preparation of a solution to the analysis performed as given in claim 2.2.2.1.

2.3.2.2. Aliquot part of the solution in accordance with the table. 1 is placed in a beaker with a capacity of 100 cm, 3−6 cm, containinghydrochloric acid (1:1) and 10 cmof water. the pH of the solution should be not more than 1.0 (control of pH-meter). Then add 2−5 cmof ascorbic acid solution and set pH (1,5±0,1) by adding in small portions while stirring the sodium hydroxide solution with a mass concentration of 50 g/DM. The solution was transferred to a volumetric flask with a capacity of 100 cm, is added with stirring 10 cmsolution of chromazurol , 5 cmsolution of polyvinyl alcohol and 20 cmbuffer solution. Dilute to the mark with water and mix.

The optical density of the solutions measured after 30 min in the spectrophotometer at a wavelength of 620 nm or photoelectrocolorimeter with a blue-green filter, having an area of transmittance 590−625 nm. As a solution comparison solution is used in the reference experiment.

To prepare the solution in the reference experiment in a glass put a suspension of carbonyl iron, corresponding to the linkage of samples and further analysis is performed as described above for PP.2.2.2.1 and 2.3.2.2.

The analysis results calculated by a calibration chart or by comparison with a standard sample similar in composition to the sample and provedenim through all stages of anal

iza.

2.4. Construction of calibration curve

In eight glasses with a capacity of 200 cmis placed carbonyl iron sample corresponding to the sample test portion in accordance with the table. 2. Seven of them added consistently 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 3,5 cmstandard solution of aluminium chloride, which corresponds to 0,00005; 0,00010; 0,00015; 0,00020; 0,00025; 0,00030; 0,00035 g of aluminum.

In the case of the presence in the sample of vanadium in glasses added a solution of vanadium in a quantity that corresponds to content in the sample the sample analyzed.

The eighth glass is used for the reference experiment. All the glasses are poured at 20−30 cmof hydrochloric acid (1:1) and dissolved by heating. Further analysis is performed as described in section 2.2.2 in the application of aluminon or paragraph 2.3.2 when performing analysis with chromazurol .

The found values of optical density and corresponding values of the mass of the aluminium build of the calibration graph. Allowed construction of calibration curve in the coordinates: the optical density is the mass fraction of aluminum.

2.5. Processing of the results

2.5.1. Mass fraction of aluminium () in percent is calculated by the formula

,

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

 — the weight of the portion of the sample,

2.5.2. Norms of accuracy and norms control the accuracy of determining the mass fraction of aluminium are given in table. 1.

3. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM ACID

3.1. The essence of the method

The method is based on decomposition of the steel sample in dilute sulfuric acid, under low heat for the most complete separation of the acid of aluminum and aluminum included in the composition of the inclusions, the solubility of which depends on acid concentration and temperature of dissolution.

Aluminium acid is determined by the photometric method with alumininum or with chromazurol .

3.2. Equipment and reagents

Apparatus, reagents and solutions according to claims.2.2.1 and 2.3.1.

3.3. Analysis

A sample of steel weighing 1 g is placed in a conical flask with a capacity of 100 cm, 30 cm, pouredsulphuric acid (1:20) and covering the flask with a watch glass and dissolve in a water bath at a temperature of 50−60 °C.

After the complete decomposition of the sample add a little ashless filter paper pulp, dilute the solution with water to 50 cmand filtered through the filter medium density in a volumetric flask with a capacity of 100 cm. The sediment and filter washed 8−10 times with hot water. Filter the precipitate discarded. The filtrate is cooled, made up to the mark with water and mix.

If the analyzed sample contains titanium, then it is separated with sodium hydroxide. For this purpose a solution after dissolving the sample filter in a glass with a capacity of 200−300 cmthrough a filter of medium density. The sediment and filter washed 8−10 times with hot water. Filter the precipitate discarded. The contents of the Cup is heated, oxidized iron, adding 2−3 cmof nitric acid, the solution is evaporated to a volume of 15−20 cm, add 5 cmof a solution of zinc chloride and 0.7 g of boric acid.

The hot solution carefully in small portions at careful hashing pour in a volumetric flask with a capacity of 100 cmcontaining the hot sodium hydroxide solution with a mass concentration of 200 g/DMin the amount of 30−50 cm, cooled, made up to the mark with water and mix. After settling the solution is filtered through a dry filter, the average density in the dry quartz beaker, discarding the first portions of the filtrate.

Further analysis is performed in accordance with paragraph 2.2.2.2 when using aluminon or claim 2.3.2.2 when using chromator

Ola .

3.4. Construction of calibration curve

Eight conical flasks with a capacity of 100 cmplaced 1 g of carbonyl iron. Seven of them successively added 0,3; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0 cmstandard solution of aluminium chloride, which corresponds to 0,00003; 0,00005; 0,00010; 0,00015; 0,00020; 0,00025; 0,00030 g of aluminum. The eighth bulb is used for the reference experiment.

In the case of the presence in the sample of vanadium in the flask was added a solution of vanadium in a quantity that corresponds to content in the sample the sample analyzed.

All flasks are poured 30 cmof sulphuric acid (1:20) and covering flasks, watch glass, dissolve in a water bath at a temperature of 50−60 °C. the analysis is performed, as indicated in paragraph 3 above.3. Allowed construction of calibration curve in the coordinates: the optical density is the mass fraction.

3.5. Processing of the results

3.5.1. Mass fraction of acid aluminium (a) percentage calculated by the formula

,

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

-the weight of the portion of the sample,

3.5.2. Norms of accuracy and norms control the accuracy of determining the mass fraction of aluminium are given in table. 1.

4. ATOMIC ABSORPTION METHOD

4.1. The essence of the method

The method is based on measurement at =309,3 nm the degree of absorption of resonance radiation by free atoms of aluminum, formed as a result of spraying the test solution into the flame nitrous oxide — acetylene.

4.2. Equipment and reagents

Atomic absorption spectrophotometer with flame atomizer.

Lamp with hollow cathode for the determination of aluminium.

The cylinder with acetylene according to GOST 5457−75.

A tank of nitrous oxide.

Hydrochloric acid by the GOST 3118−77 or GOST 14261−77 and diluted 1:1 and 1:100.

Sulfuric acid GOST 4204−77, diluted 1:4.

Nitric acid GOST 4461−77.

Hydrofluoric acid according to GOST 10484−78.

Potassium-sodium carbonate according to GOST 4332−76.

Salt is the disodium Ethylenediamine-, , , -tetraoxane acid, 2-water (Trilon B) according to GOST 10652−73, a solution with a mass concentration of 50 g/DM.

Aluminium metal according to GOST 11069−74, brand А999, A995, A99, A97.

Standard solutions of aluminium.

Solution a: 0.5 g of aluminum metal is placed in a beaker with a capacity of 250−300 cmand dissolved under moderate heating in 40−50 cmof hydrochloric acid (1:1). Cautiously added dropwise 5−7 cmof nitric acid and boil to remove oxides of nitrogen. Then pour 100−150 cmof hot water, the solution was cooled, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of aluminium.

Solution B: 10 cmsolution 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 and

of Lumina.

4.3. Preparation of the device

The device is prepared in accordance with the enclosed instructions. Set the spectrophotometer at a resonance line of 309,3 nm. After turning on gas supply and ignition of the burner in the flame spray water and set the zero readings.

4.4. Analysis

4.4.1. The weight of steel or cast iron weighing 1 g is placed in a beaker with a capacity of 250−300 cmand dissolved by heating at 20−50 cmof hydrochloric acid. Then cautiously, drop by drop, add 5−10 cmof nitric acid. The solution was evaporated to dryness. Salt dissolved in 5 cmof hydrochloric acid in low heat, add 40−50 cmof hot water and filter the solution through two filters «white ribbon» with the addition of filter-paper pulp. Filter the precipitate was washed several times with hot hydrochloric acid (1:100) and two or three times with hot water. The filtrate is saved.

The filter with precipitate was placed in a platinum crucible, dried, incinerated and calcined for 7−10 minutes at 800−900 °C.

Cool the crucible, add a few drops of water, 3−4 drops of sulphuric acid, 4−5 cm inhydrofluoric acid and evaporated to remove vapors of sulfuric acid.

Then, the crucible was calcined for 5−7 minutes at 800−900 °C, cooled, add 1−1,5 g potassium carbonate, sodium and fused contents of the crucible at 1000−1100 °C. After cooling, the melt is leached with hot water, add 10 cmof hydrochloric acid and dissolved by heating.

The solution attached to the original filtrate is evaporated to 20−30 cm, add 10 cmof the solution Trilon B, is cooled and transferred to volumetric flask with a capacity of 50 cm.

Allowed another dilution of the solution so that the final concentration of aluminum was in the range of corresponding straight-line segment calibration curve.

The solution is filtered through dry filter «white ribbon», discarding the first two portions of the filtrate.

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

Spray the control and test solutions in order of increasing absorption to obtain stable readings for each solution. Prior to introduction into the flame each of the analyzed solution is sprayed water to wash the system and check the zero reading of the instrument.

From the average value of absorbance of each of the analyzed solutions, the average value is subtracted absorption in the reference experiment.

The results of the analysis calculated by the calibration graph

the IR.

4.4.2. Construction of calibration curve

Six glasses with a capacity of 250−300 cmis placed 1 g of carbonyl iron. Five of them add 5; 7; 9; 10; 12 cmstandard solution B, which corresponds to 0,0005; 0,0007; 0,0009; 0,0010; 0,0012 g of aluminum. Then do as given in claim 4.4.1.

The sixth glass is used for the reference experiment.

The solutions were sprayed in order of increasing absorption, starting from the control solution. Before spraying each solution is sprayed water. From the average value of absorbance of each solution is subtracted the average value of absorbance of control solution. The found values of absorbance of solutions and their corresponding mass values of aluminium to build the calibration graph.

4.5. Processing of the results

4.5.1. Mass fraction of aluminium () in percent is calculated by the formula

,

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

 — the weight of the portion of the sample,

4.5.2. Norms of accuracy and norms control the accuracy of determining the mass fraction of aluminium are given in table. 1.