GOST 23949-80

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  ГОСТ 23949-80

GOST 23949−80 a tungsten non-consumable welding Electrodes. Specifications

GOST 23949−80

Group В05

INTERSTATE STANDARD

THE TUNGSTEN NON-CONSUMABLE WELDING ELECTRODES

Specifications

Welding nonconsumable tungsten electrodes. Specifications

ISS 25.160.20
GST 18 5374 0000

Date of introduction 1981−01−01

Resolution of the USSR State Committee on standards of January 18, 1980, No. 217 date of introduction is established with 01.01.81

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

REPRINTING. September 2004

This standard applies to the electrodes of pure tungsten and tungsten with activating additives (thorium dioxide, oxides of lanthanum and yttrium), designed for arc welding with non-consumable electrode in inert gases (argon, helium) and also for plasma processes of cutting, welding and spraying.

1. BRAND

1.1. Depending on the chemical composition of the electrodes must be manufactured from tungsten grades specified in table.1.

Table 1

2. ASSORTMENT

2.1. The dimensions of the electrodes and limit deviations shall be as specified in table.2.

Table 2

mm

Example of designation electrode brand ml, diameter 2.0 mm, length 150 mm:

Electrode tungsten EVL-2−150 — GOST 23949−80

3. TECHNICAL REQUIREMENTS

3.1. Tungsten electrodes shall be manufactured in accordance with the requirements of the standard grades of pure tungsten and tungsten with activating additives, the chemical composition of which is as specified in the table.3.

Table 3

Notes:

1. Listed in the table are the mass fraction of oxides of lanthanum, oxides of yttrium, thorium dioxide and tantalum are included in the mass fraction of tungsten.

2. For brand ml Nickel in the amount of impurities is not included.

3.2. On the surface of the electrodes should be no shells, bundles, cracks, oxides, residues, technological lubricants, impurities and contaminants.

On the electrode surface, treated by centerless grinding to the size as shown in table.2, not allowed cross risks grinding to a depth of more than half of the maximum deviations in diameter.

3.3. The surface of the electrodes made by the lug, needs to be cleaned of oxides, technological lubricants and other contaminants by chemical treatment (by etching).

On the electrode surface are not allowed the marks to a depth of more than half of the tolerance on the diameter.

3.4. The non-uniformity of diameter along the length of the electrodes and ovality must not exceed the limit deviation for diameter.

3.5. The electrodes should be straight. Napravlennosti electrodes should not be more than 0.25% of the length.

3.6. The ends of the electrodes should have a straight cut. Are not allowed on the crosscut end of the electrode chips value limit deviation for diameter.

3.7. The internal stratification and cracks are not allowed.

4. ACCEPTANCE RULES

4.1. The electrodes take parties. The party must consist of electrodes made from one batch of cooking, and decorated by one document on quality.

The document about quality should contain:

the name of the manufacturer and trademark of the manufacturer;

the name and brand of the product;

batch number;

results of the chemical analysis;

the date of manufacture;

the weight of the batch and the number of seats in the party;

the designation of the standard.

The document about quality put in box No. 1.

The mass of the batch shall not be more than 1300 kg.

4.2. For the determination of activating additives are selected three to five welded or sintered shtabikov from each party.

Determination of impurities is pursuing the manufacturer for each batch of tungsten powder sample according to GOST 20559−75.

4.3. The compliance of the electrodes PP.2.1, 3.2−3.7 is carried out on each electrode.

4.4. If unsatisfactory results on the chemical composition of it is carried out re-testing at twice the sample taken from the same batch. The results of repeated tests apply to the entire party.

5. TEST METHODS

5.1. Sampling and sample preparation

5.1.1. For the determination of activating additives from samples taken three to five shtabikov, beat off pieces weighing 30−50 g, and wear them in a mechanical mortar.

The resulting powder is subjected to magnetic separation.

5.2. The content of impurities of aluminum, iron, silicon, molybdenum, calcium, Nickel is determined according to GOST 14339.5−91.

The contents of activating additives (thorium dioxide, lanthanum, yttrium) is determined according to the methods set out in the Annex.

The tungsten content determined by the difference between the 100% and the sum of the content of impurities.

5.3. The geometrical dimensions, the uniformity of diameter along the length and the roundness of the electrodes was checked with a micrometer according to GOST 6507−90 or caliper according to GOST 166−89, and a ruler according to GOST 427−75.

5.4. The surface quality of the electrodes are checked visually. When disagreement in assessing the quality of used optical means and measuring tool.

5.5. The straightness of the electrodes is checked with the dipstick on the other 2−034−225−87* on a flat metal plate according to GOST 10905−86.
________________
* Document authoring is. For additional information, please refer to the link. — Note the manufacturer’s database.

5.6. Of the absence of internal delaminations and cracks are carried out using eddy current flaw detector.

6. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

6.1. Each electrode shall be marked in accordance with table.4.

Table 4

Electrodes with a diameter of 3.0 mm and allowed to label the chamfering 1 mm45° or scratches.

The marking must be applied to one end of the electrode.

The marking may be applied on the end face in the form of stripes or dots on the surface at the end on a length of 5−10 mm.

Color coding is recommended for nitrocellulose lacquer NC-62 according to normative-technical documentation.

6.2. Electrodes of the same brand, same diameter must be placed in cardboard boxes with tool trays from foam, corrugated or molded heavy paper.

6.3. Each box of electrodes labeled as containing:

the name of the manufacturer or his trademark;

the name of the product;

designation of the product;

quantity;

batch number;

the date of issue;

the appearance of the marking;

stamp of technical control.

6.4. The box with the electrodes packaged in wooden boxes according to GOST 2991−85 type 1 or 2 laid out inside the packaging waterproof paper GOST 8828−89. The remaining free volume of the box is filled tightly wrapping paper or cotton wool GOST 5679−91.

Weight box gross no more than 40 kg.

6.5. The marking drawer is carried out according to GOST 14192−96 with application of additional data:

names, brands, sizes of electrodes;

batch number;

date of packing;

of the net mass.

6.6. Packed electrodes transporterowych all types of transport in covered vehicles.

During transport, the stowage boxes need to warn of their movement, mechanical damage to the packing and electrodes, moisture.

Conditions of transportation in terms of the impact of climatic factors — according to the group GHOST 15150−69.

6.7. Stored electrodes should be in the package under section 6.4, the group of storage conditions L GOST 15150−69.

APP (mandatory)

APP
Mandatory

1. METHOD OF DETERMINATION OF OXIDES OF LANTHANUM

Method sets the definition of the oxides of lanthanum, tungsten stabika antoninovna welded and the electrodes.

1.1. The essence of the method

The method is based on separation of lanthanum from dissolution of tungsten pre-oxidized and calcined test sample to tungsten dioxide () in the sodium carbonate solution.

The lanthanum in the tungsten in the form , is precipitated, and a soluble form of lanthanum dooradult the ammonia .

The precipitate was filtered off, dissolved in hydrochloric acid and again precipitated by all of the lanthanum in the form of ammonia which is filtered, washed and calcined to .

The accuracy of the method when the mass fraction of the oxide of lanthanum from 1% to 3% is 0.1% when the mass fraction of the oxide of lanthanum is less than 1% to -0.05%.

1.2. Reagents

Sodium carbonate crystal according to GOST 84−76, 30% solution.

Ammonia water according to GOST 3760−79, 25% solution.

Hydrochloric acid by the GOST 3118−77, density 1.12 g/cm.

Distilled water GOST 6709−72.

1.3. Sample preparation

Tungsten oxide, pre-calcined in a muffle furnace at 700−750 °C for 1.5−2 hours

Tungsten powder, rod billet from the alloy or the electrode is oxidized to the trioxide by calcining in a muffle furnace at a temperature of 700−750 °C. the sample is poured in a porcelain crucible at 1/3 of its height and put in the muffle at 400−500 °C for 1.5−2 h, and then raising the temperature up to 700−750 °C and held the crucible to complete oxidation of the powder (~3 hours).

For uniform oxidation of the tungsten crucible two or three times removed from the furnace and the sample is stirred.

1.4. Analysis

2−3 g of tungsten anhydride were placed in a glass 150−200 cm, pour 50−70 cmof sodium carbonate solution and dissolved by heating.

After dissolving tungsten dioxide solution diluted with distilled water to a volume of ~100 cm, added 20−30 cmof ammonia solution, the glass is placed in the electric bath, and the residue to give koagulirovat. The precipitate was filtered through a filter «white ribbon» with the adsorbent was washed with warm 5% solution of ammonia; filter the precipitate is placed in a beaker, in which was conducted the deposition, add 15−20 cmof hydrochloric acid and heat the contents of the beaker to dissolve the precipitate and matseratsii filter.

The content of the beaker was diluted with distilled water to 80−100 cm, the pulp is filtered two or three times washed with acidified hot water, combining the washings with the main filtrate.

The filtrate is neutralized with ammonia solution on litmus, and then poured another 15−20 cmof ammonia.

The precipitate is allowed to koagulirovat, then it was filtered through the filter «white ribbon» with the adsorbent. The precipitate is washed with hot water, which added a few drops of ammonia solution to a negative reaction to (test and ).

Washed the precipitate with the filter placed in a pre-calcined and weighed porcelain crucible, incinerated and calcined in a muffle furnace at a temperature of 700−750 °C to constant weight.

1.5. Processing of the results

Mass fraction of oxide of lanthanum, the percentage calculated by the formula

,

where is the mass of sediment, g;

 — the weight of the portion of tungsten anhydride (), g;

 — the conversion factor with tungsten dioxide to tungsten.

Note. Calcined precipitate of lanthanum oxide includes iron oxide, the amount of which is very small compared to the amount of oxide of lanthanum, so the mass of iron oxide can be neglected.


If you want the definition of pure oxide of lanthanum, the calcined precipitate is dissolved in hydrochloric acid, colorimetric iron and by difference determine the mass of an oxide of lanthanum.

2. METHOD OF DETERMINATION OF OXIDES OF YTTRIUM

Method sets the definition of an oxide of yttrium in tungsten stabika utrirovannye welded and the electrodes.

2.1. The essence of the method

The method is based on the separation of yttrium from tungsten by dissolving the test sample in hydrofluoric acid with addition of nitric acid.

When the mass fraction of oxide of yttrium, 1 to 3% margin of error of the method is 4−5%.

2.2. Apparatus, reagents and solutions

Drying Cabinet, providing heating to a temperature of (150±50) °C.

Muffle furnace with thermocouple, providing heating to a temperature of (1100±50) °C.

Cups and crucibles platinum — GOST 6563−75.

Laboratory glassware porcelain — GOST 9147−80.

Hydrofluoric acid (hydrofluoric acid) — according to GOST 10484−78.

Nitric acid GOST 4461−77.

Ammonia water — GOST 3760−79 diluted 1:1.

Funnel plastic.

Distilled water GOST 6709−72.

Rectified ethyl alcohol — GOST 5962−67*.
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* On the territory of the Russian Federation GOST R 51652−2000.

Filter paper laboratory GOST 12026−76.

2.3. Sample preparation

Samples utrirovannoe tungsten is cleaned from possible contamination by washing several times with ethanol and subsequent drying in a drying Cabinet at a temperature of 50−70 °C for 10 min.

Prepared samples stored in glass buksh or test tubes with ground stoppers.

2.4. Analysis

A sample weighing 1 g is placed in a platinum Cup with a capacity of 100 cm, add 25−30 cmof hydrofluoric acid and cautiously add drop by drop nitric acid to dissolve the metal.

After complete dissolution of tungsten and the termination of allocation of oxides of nitrogen in a Cup add 30 cmof water, heated to a temperature of 80−90 °C.

The solution and the precipitate was allowed to settle for 1 h, then filtered through a polyethylene funnel.

Prior to filtering, the filter is placed a small amount of adsorbent.

After transferring the precipitate to the filter, the bottom of the Cup, wipe with a piece of wet filter and all content on it is drained on the filter with hot water. The precipitate is then washed five or six times a hot ammonia solution (60−70 °C) and two or three times with hot water.

The washed precipitate is transferred into a previously weighed porcelain crucible, dried in a drying Cabinet at a temperature of 100−150 °C and then calcined in a muffle furnace at a temperature of 650−700 °C to constant mass and weighed in the form of an oxide of yttrium.

2.5. Processing of the results

Mass fraction of yttrium oxide in percentage is calculated by the formula

,

where is the mass of ignited residue, g;

 — the weight of the portion of the sample,

3. THE METHOD OF DETERMINING THE CONTENT OF THORIUM DIOXIDE

The method sets the definition of dioxide of thorium in thoriated tungsten welded stabika and the electrodes.

3.1. The essence of the method

The method is based on formation of sludge in the dissolution of the sample in a mixture of hydrofluoric and nitric acids.

Accuracy of the method for the mass concentration of thorium dioxide from 1.5% to 2% is 0.1%.

3.2. Reagents

Hydrofluoric acid (hydrofluoric) — GOST 10484−78.

Nitric acid GOST 4461−77.

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

Distilled water GOST 6709−72.

3.3. Sample preparation

Samples are boiled for several minutes in an alkali solution to remove oxides from the surface, washed in distilled water and dried in a drying Cabinet.

3.4 analysis

The hitch weight of 1−2 g was placed in a platinum Cup with a capacity of 100 cm, add 25−30 cmof hydrofluoric acid and cautiously added dropwise nitric acid.

After complete dissolution of tungsten and the termination of allocation of oxides of nitrogen in a Cup add 30 cmof hot water. The solution to precipitate oxide of thorium allowed to settle for 1 h, then filtered through rubber, vinyl or platinum funnel.

Prior to filtering, the filter is placed a small amount of adsorbent.

After transferring the precipitate to the filter, the bottom of the Cup, wipe with a piece of wet filter and wash with a Cup of hot water. When the precipitate of oxide of thorium completely transferred to the filter, it is washed several times with hot water, and then five or six times a hot solution of ammonia and two or three times with hot water.

The moist filter is transferred to a pre-weighed to constant weight porcelain or platinum crucible, incinerated, and calcined at a temperature of 750−800 °C and weighed.

At the same time conducting follow-up experience with all reagents.

3.5. Processing of the results

Mass fraction of thorium dioxide in percentage is calculated by the formula

,

where is the mass of sediment , g;

 — the mass of sediment in a control experiment, g;

 — the weight of the portion of the sample,