GOST 22974.13-96

• gost-2297413-96.pdf (150.04 KiB)
  ГОСТ 22974.13-96

GOST 22974.13−96 fused welding Fluxes. Method for determination of carbon

GOST 22974.13−96

Group B09

INTERSTATE STANDARD

FUSED WELDING FLUXES

Method for determination of carbon

Melted welding fluxes.
Method of carbon determination

ISS 77.040
AXTU 0809

Date of implementation 2000−01−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 72; the Institute of electric them. E. O. Paton of NAS of Ukraine

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology, dated April 21, 1999 N 134 inter-state standard GOST 22974.13−96 introduced directly as state standard of the Russian Federation from January 1, 2000

4 REPLACE GOST 22974.13−85

1 Scope

This standard sets the coulometric method for determining carbon content of from 0.01 to 0.1%.

2 Normative references

The present standard features references to the following standards:

GOST 3118−77 hydrochloric Acid. Specifications

GOST 4140−74 Strontium chloride 6-water. Specifications

GOST 4199−76 Sodium tetraborate 10-aqueous. Specifications

GOST 4207−75 Potassium ferrocyanide 3-aqueous. Specifications

GOST 4234−77 Potassium chloride. Specifications

GOST 5583−78 Oxygen gas technical and medical. Specifications

GOST 9147−80 Glassware and equipment lab porcelain. Specifications

GOST 16539−79 Copper (II) oxide. Specifications

GOST 22974.0−96 fused welding Fluxes. General requirements for methods of analysis

3 General requirements

General requirements for methods of analysis GOST 22974.0.

4 Coulometric method for determining carbon

4.1 the essence of the method

The method is based on burning the sample in a current of oxygen in presence of flux at a temperature of 1300 °C, the absorption of the formed carbon dioxide absorption by a solution with a particular initial pH value, and then measure necessary to restore the original pH value of the amount of electricity proportional to the mass fraction of carbon in the linkage sample.

During heating the flux up to 1300 °C simultaneously with the carbon dioxide escapes, and fluoride of silicon.

To absorb the fluoride of silicon is set to a column filled wet anionite resin EDE-10P. Fluoride silicon to wet the resin is hydrolyzed. Silicic acid is released in the form of a white plaque on the surface of the wet resin and hydrofluoric acid is absorbed anionite resin.

4.2 Equipment, reagents and solutions

Setup for determination of carbon

Figure 1 — Installation for determination of carbon

1 — oxygen cylinder according to GOST 5583, pressure reducing valve start-up and adjustment of a current of oxygen;

2 — reducer-pressure gauge fine adjustment of a current of oxygen; 3 — absorber filled with Astarita;
4 — tube furnace providing heating up to 1300 °C; 5 — boat-porcelain N 2 according to GOST 9147,
calcined at 1300 °C in flowing oxygen; 6 — tube porcelain inner diameter of 20−22 mm,
length 650−750 mm; 7 — vessel-absorber 25 mm in diameter and 150 mm in height with branches for supplying
rubber tubes filled with wet anionite resin EDE-10P. This absorber allows
spend 15−20 definitions of carbon. Then it should be replaced or recharged. In the upper and lower
of the container put pieces of paper of the Congo. The blue paper at the top of the absorber indicates
that hydrofluoric acid is in a cell and need to change the absorber;
8 — Express carbon analyzer an-7560, or other similar types

Figure 1 — Installation for determination of carbon

The hook with which the boat was placed in a tube and extracted from it, is made of heat-resistant wire with a diameter of 3−5 mm and a length of 500−600 mm.

Hydrochloric acid according to GOST 3118, solution mass concentration of 1%.

Potassium ferrocyanide 3-water according to GOST 4207.

Potassium chloride according to GOST 4234.

Strontium chloride 6-water according to GOST 4140.

Askari.

Copper (II) oxide according to GOST 16539, calcined at 800 °C for 4−5 h.

Sodium tetraborate 10-water according to GOST 4199.

Anionity resin EDE-10P. The resin was pre-flooded with distilled water for a day, and then washed with water several times.

The absorption solution: 50 g of potassium chloride, 50 grams of strontium chloride and 1 g of sodium tetraborate is dissolved in 1000 cmof distilled water.

Auxiliary solution: 50 g of potassium chloride and 50 g potassium ferrocyanide dissolved in 1000 cmof distilled water.

4.3 analysis

Weighed flux weighing 0.5 g is placed in a porcelain boat, add 0.5 g of copper oxide and stirred. A boat with linkage and flux are placed in the most heated portion of the porcelain tube, the end of which is immediately closed with shutter. Burning is carried out for 2 min.

4.4 Processing of results

4.4.1 Mass carbon fraction , %, at the sample of 0.5 g corresponds to the indication of the digital display device subject to control of the experience

, (1)

where is the testimony of a digital display device, the resulting combustion of the sample of the analyzed material, %;

 — the readings obtained by burning flux.

4.4.2 Standards of accuracy and standards for monitoring the accuracy of determining the mass fraction of carbon is given in table 1.


Table 1

Percentage