GOST 11930.1-79

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  ГОСТ 11930.1-79

GOST 11930.1−79 Materials surfacing. Methods for determination of carbon (with Amendments No. 1, 2)

GOST 11930.1−79

Group B09

INTERSTATE STANDARD

MATERIALS SURFACING

Methods for determination of carbon

Hard-facing materials. Methods of carbon determination

ISS 25.160.20
AXTU 1709

Date of introduction 1980−07−01

The decision of the State standards Committee of the USSR Council of Ministers dated 21 March 1979 N 982 date of introduction is established 01.07.80

Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)

REPLACE GOST 11930−66 in part of sec. 8

EDITION (August 2011) with Amendments No. 1, 2 approved in December 1984, December 1989 (IUS 3−85, 3−90)


This standard sets by a gas-volume (when mass fraction of carbon from 0.1 to 30%), potentiometric (when the mass fraction of carbon from 0.010 to 7.00%), coulometric (with carbon mass fraction from 0.01 to 7.00%) methods for determination of carbon in hardfacing materials.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 11930.0−79.

2. BY A GAS-VOLUME METHOD FOR DETERMINATION OF CARBON

2.1. The essence of the method

The method is based on the combustion of a test sample in flowing oxygen at 1250−1350 °C followed by absorption of carbon dioxide with a solution of potassium hydroxide.

The carbon content is determined by difference between the initial volume of the mixture gases (co+O) and the volume of gas obtained after absorbing the carbon dioxide with a solution of potassium hydroxide.

(Changed edition, Rev. N 2).

Damn.1. Setup for determination of carbon

Installation for the determination of carbon(Fig.1)

Damn.1

2.2. Apparatus, reagents and solutions

The installation consists of the following elements: cylinder 1 oxygen (GOST 5583−78), equipped with reducing valve, rotameter 2 PC-OVER; flask with a tube 3with a capacity of 250−400 cm, filled with Astarita; resistance furnace 4 with sheltowee heaters, providing a working temperature of 1400±20 °C; dust filter 5, which is a glass tube with a spherical thickenings, filled with cotton; the glass tube 6, filled with granular manganese dioxide; by a gas-volume analyzer 7 type go-1 audiometros 4.5%.

Potassium hydroxide.

Methyl orange.

Pumps porcelain LS N 2 according to GOST 9147−80.

Tube mullite refractory-silica according to normative-technical documentation.

Manganese sulfate according to GOST 435−77.

Granulated manganese dioxide and 200 g of manganese sulfate is dissolved in 2500 cmof hot water, then in the solution add 25 cmof ammonia, add 1000 cmto 22.5% strength solution naternicola ammonium and the mixture boiled for 10 min. while boiling, add ammonia to alkaline reaction, then the solution to stand until complete precipitation of manganese dioxide. The precipitate was filtered off, washed and dried at 110 °C.

Ammonia according to GOST 3760−79.

Ammonium neccersarily according to GOST 20478−75, 22,5% solution.

Copper (II oxide wire) h.d. a.

The technical rectified ethyl alcohol GOST 18300−87.

A standard sample.

(Changed edition, Rev. N 1, 2).

2.3. Preparation for assay

Before starting, the installation check for leaks.

Set the oxygen flow rate 300 cm/min.

To check the correct operation of the device it is necessary to conduct the burning of several batches of a standard sample.

Use standard samples category of the CCA and SOP, in which the certified mass fraction of component is not different from that analyzed more than two times.

Pumps calcined in flowing oxygen at 1300−1350 °C for 3 min.

The analyzed samples purified from impurities by washing them with alcohol at the rate of 10 cmper sample, and dried.

(Changed edition, Rev. N 1, 2).

2.4. Analysis

A portion of the analyzed material is placed in a boat calcined and thoroughly mixed with the flux — oxide of copper. The beach, taken in the ratio 1:3.

The boat is loaded into a pipe for combustion from the oxygen. Oven temperature 1300−1350 °C.

The magnitude of the sample with different contents of carbon are shown in table.2.

Table 2*
_________________
* Table 1. (Deleted, Rev. N 2).

2.5. Processing of the results

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

,

where  — indications of the scale of audiometry corresponding to the mass fraction of carbon, %;

 — indications of the scale of audiometry corresponding test experiment, %;

 — correction factor for temperature and atmospheric pressure, was found in the table annexed to the instrument;

the ratio of burnout of a standard sample that represents the ratio of the percentage of carbon according to the testimony on the standard sample to the percentage obtained by audiometry;

 — the weight of the portion of the sample,

2.5.2. The difference between the largest and smallest results of the three parallel measurements, and the two results of the analysis at a confidence level of 0.95, should not exceed the values of permissible differences given in table.3.

Table 3

(Changed edition, Rev. N 2).

3. POTENTIOMETRIC METHOD FOR DETERMINATION OF CARBON

3.1. The essence of the method

The method is based on the combustion of a test sample in flowing oxygen at 1300−1350 °C followed by absorption of the formed carbon dioxide electrolyte solution.

Titration of the electrolyte with a solution of hydroxide of barium pH is brought to the initial pH value 10.

(Changed edition, Rev. N 2).

3.2. Apparatus, reagents and solutions

The installation consists of the following elements (Fig.2): of a cylinder 1 with a pressure reducing valve with oxygen (GOST 5583−78); rotameter 2 PC-3A; dogtramadol furnace 5 with sheltowee heaters, providing temperatures up to 1400±20 °C; flask 3 with Astarita; startup shutter 4; dust filter 6; a capillary choke 7; flask 8filled with granular manganese dioxide; electrolytic cell 9, into which is placed the mixer 10 with the motor 13; the electrode system 11; dropper 12 to enter into the cell titrant; burette 14, with a capacity of 10−25 cm; magnetic valve 15; the normal of the element 17; the pH meter 16 of the type pH 340 or pH 121 and the block of automatic titration 18.

Damn.2. Setup for determination of carbon

Setup for determination of carbon

Damn.2

Note. Instead of a burette 14, the magnetic valve 15 can be to use the automatic burette dispenser B-701. Electrolytic cell 9 with a capacity of 200 cmcan be replaced by a vessel with a porous filter N 2 or 3 with a capacity of 100 cm.


The lime soda.

Pumps porcelain LS N 2 according to GOST 9147−80.

Potassium chloride according to GOST 4234−77, saturated solution.

Copper (II oxide wire) h.d. a.

Barium chloride according to GOST 4108−72, the electrolyte solution is prepared as follows: 10 g of barium chloride dissolved in 1000 cmof distilled water and to the obtained solution poured 10 cmof ethanol.

Barium hydroxide according to GOST 4107−78, saturated solution; prepared as follows: an oxide hydrate of barium dissolved in distilled water (pre-boiled for 2 h and cooled to room temperature). The resulting solution was diluted 10 times.

The solution is stored in bottles fitted with tubes with soda lime. The mass concentration of the solution of hydroxide of barium is set according to the standard model.

Tube porcelain inner diameter of 20−21 mm.

The technical rectified ethyl alcohol GOST 18300−87.

3.3. Preparation for assay

Set up a pH meter and BAHT. The electrode system set up against the buffer solution of 9.18 pH-9,22 (fixanal 0.01 mol/DMsolution of potassium tetraborate). To the output of the pH meter 0−2 connects the block automatic titration series using normal element.

Pumps calcined in flowing oxygen at 1300−1350 °C for 3 min.

Electrolytic cell filled with electrolyte in the amount of 300−400 cmand connect it with the output of the oxygen out of the porcelain tube in which the burn test.

Set the oxygen flow rate is 700 cm/min. Include the BAT in the titration and the pH adjusted to 10.

Burn standard sample.

3.1−3.3. (Changed edition, Rev. N 2).

3.4. Analysis

Depending on the carbon content of the samples take a variety of sample (tab.4).

Table 4

The sample is placed in a boat calcined and thoroughly mixed with the flux — copper oxide in a ratio of 1:3.

The boat with sample and flux is placed in the working tube, close the gate and include a block of automatic titration for titration «Up». Once you see the light «end of titration» on the burette count the number of solution of hydrate of an oxide of barium, used for titration.

After the analysis, 50−70 samples, the electrolyte solution must be replaced.

3.5. Processing of the results

3.5.1. Mass fraction of carbon () in percent is calculated by the formula

,

where  — the volume of the titrated solution of hydroxide of barium, used for titration of the sample, cm;

 — the volume of the titrated solution of hydroxide of barium, used for titration of the reference experiment, cm;

 — mass concentration of a solution of hydroxide of barium, expressed in g/cmcarbon;

 — the weight of the portion of the sample,

3.5.2. The difference between the largest and smallest results of the three parallel measurements, and the two results of the analysis at a confidence level of 0.95 does not exceed the permissible differences given in table.5.

Table 5

3.5.1, 3.5.2. (Changed edition, Rev. N 2).

4. COULOMETRIC METHOD FOR DETERMINING CARBON

4.1. The essence of the method

The method is based on the combustion of a test sample in flowing oxygen at 1250−1400 °C, followed by absorption of the formed carbon dioxide electrolyte solution.

4.2. Apparatus, reagents and solutions

Coulometric analyzer an-29, an-7529, 7560 or an any type.

Resistance furnace, providing the temperature 1400±20 °C.

Cylinder with reducing valve with oxygen according to GOST 5583−78.

Pumps porcelain LS N 2 according to GOST 9147−80.

The technical rectified ethyl alcohol GOST 18300−87.

Copper (II oxide wire) h.d. a.

Tube mullite refractory-silica according to normative-technical documentation.

(Changed edition, Rev. N 1).

4.3. Preparation for assay

Include the analyzer to the network and configured.

Pumps calcined in flowing oxygen at 1300−1350 °C for 3 min.

The analyzer is calibrated by standard samples.

4.2, 4.3. (Changed edition, Rev. N 2).

4.4. Analysis

Depending on the mass fraction of carbon in the different samples take the sample in accordance with table.6.

Table 6

A portion of the calcined sample was placed in a boat and thoroughly mixed with the flux — copper oxide in a ratio of 1:3.

The boat with sample is placed in a combustion tube, close the shutter and turn on the device for titration.

4.5. Processing of the results

4.5.1. Mass fraction of carbon in percent is calculated as the difference between the readings of the scoreboard for the sample and control experience.

4.5.2. The difference between the largest and smallest results of the three parallel measurements, and the two results of the analysis at a confidence level of 0.95, should not exceed the values of permissible differences given in table.7.

Table 7

4.5.1, 4.5.2. (Changed edition, Rev. N 2).