GOST 11930.2-79

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  ГОСТ 11930.2-79

GOST 11930.2−79 Materials surfacing. Method for the determination of sulfur (with Amendments No. 1, 2)

GOST 11930.2−79

Group B09

INTERSTATE STANDARD

MATERIALS SURFACING

Method for the determination of sulfur

Hard-facing materials. Method of sulphur determination

ISS 25.160.20
AXTU 1709

Date of introduction 1980−07−01

The decision of the State Committee USSR on standards on March 21, 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. 7

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


This standard specifies politicalticker method for the determination of sulphur (when the mass fraction of sulfur from 0.005 to 0.5%) in rods for welding, powder alloys for welding, mixture of powders for surfacing.

The method is based on the combustion of weighed portion of the sample in flowing oxygen at 1250−1350 °C. the Sulfur in the sample is combusted to sulfur dioxide which is then in the absorption vessel is absorbed in water to form sulphurous acid, which octarepeat solution yodit-Iodate in the presence of an indicator — starch.

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

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

2. APPARATUS, REAGENTS AND SOLUTIONS

Setup for the determination of sulfur (hell.1) consists of the following elements: cylinder 1 oxygen according to GOST 5583−78 with gear; flowmeter 2 type RS-3A or RM-A GOST 13045−81; furnace dogtramadol 6 with sheltowee heaters providing a temperature 1350−1400 °C; a gas washing bottle 4filled with Astarita; a gas washing bottle 3filled with a granular manganese dioxide; startup shutter 5; a capillary choke 7; dust filter 8 and the analyzer 9, which is used as the instrument type LMF-69, TFL-64 or TFLP-579 ('67), block of automatic titration and burette with an automatic valve or an automatic burette.

The analyzer is placed in the absorption vessel according to GOST 25336−82, with a capacity of 150 cm.

Pumps porcelain ЛС2 N 2 according to GOST 9147−80.

Microburette for NTD with a capacity of 2−5 cm.

Bottles for washing gases according to GOST 23932−90.

Damn.1. Setup for the determination of sulfur

Damn.1*

_____________
* Drawing 2. (Deleted. Izm. N 2).


Potassium iodide according to GOST 4232−74.

Hydrochloric acid by the GOST 3118−77.

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

Copper (II oxide wire) h.d. a.

The block of automatic titration.

The technical rectified ethyl alcohol GOST 18300−87.

Instead of using the analyzer you can use the vessel for comparison.

The soluble starch according to GOST 10163−76, an aqueous solution with a mass fraction of 0.05%.

Manganese sulfate according to GOST 435−77.

Granulated manganese dioxide; preparation of manganese dioxide according to GOST 11930.1−79.

The absorption solution is prepared as follows: to 1000 cmaqueous solution of starch pour 5 cmof hydrochloric acid.

Iodine GOST 4159−79, titrated solution; prepared as follows: a portion of the iodine mass 0,6345 g is placed in a measuring flask with volume capacity of 1000 cm, which had previously placed 4 g of potassium iodide, dissolve, add distilled water to the mark and mix. The solution was stored in a flask made of dark glass.

(Changed edition, Rev. N 1).

3. PREPARATION FOR ASSAY

The porcelain boat was calcined in flowing oxygen at 1300−1350 °C for 3 min.

The analyzed sample was washed with alcohol and dried.

In the absorption vessel pour 120 cmabsorption solution, place the vessel in the slot of the analyzer, is lowered into the vessel, the rod of the stirrer and adjust the stirring speed of the solution.

Set the oxygen flow rate 1 DM/min.

Bring the color of the absorption vessel to blue (wavelength 440−460 nm).

Then burn two samples with a high content of sulfur to stabilize the absorption of the solution.

The titer of the iodine solution set according to the standard model.

(Changed edition, Rev. N 2).

4. ANALYSIS

Depending on the sulfur content in the sample take a sample with a mass in accordance with table.1.

Table 1

A portion of the sample should be thoroughly mixed with flux — copper oxide in a ratio of 1:3.

A porcelain boat placed in a tube for combustion and automatic titration unit include the handle «titration».

After the device automatically turns off, count the volume of iodine consumed for titration. Then effect the combustion of the next sample.

At the end of the tests the burette and absorption vessel are washed with distilled water.

5. PROCESSING OF THE RESULTS

5.1. Mass fraction of sulfur () in percent is calculated by the formula

,

where is the titrated volume of iodine solution consumed for titration, cm;

the titrated volume of iodine solution consumed for titration of the solution in the reference experiment, cm;

 — mass fraction of iodine solution, expressed in g/cmsulfur;

 — the weight of the portion,

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.2.

Table 2

5.1, 5.2. (Changed edition, Rev. N 2).