GOST 7565 74 for ferrous metals. Cast iron, steel and alloys

GOST 7565-81
(ISO 377-2-89)

Group B09

INTERSTATE STANDARD

CAST IRON, STEEL AND ALLOYS

Sampling method for determining chemical composition

Iron, steel and alloys. Sampling for determination of chemical composition

MKS 77.080.01
OKSTU 0809

Date of introduction 1982-01-01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Metallurgy

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated December 30, 1981 N 5786

3. Appendix 4 of this standard has been prepared by direct application of the international standard ISO 377-2-89 "Selection and preparation of specimens and test samples for forged steel. Part 2: Specimens for determination of chemical composition"

4. INSTEAD GOST 7565-73

5. The validity period was removed by Decree of the USSR State Standard of 06.17.91 N 879

6. EDITION (September 2009) with Amendments No. 1, 2, approved in June 1986, June 1991 (IUS 9-86, 9-91)

This standard establishes a method for selecting and preparing samples to determine the chemical composition of blast furnace iron, steel, alloys and finished products.

It is allowed to select and prepare samples of forged steels for testing according to the international standard ISO 377-2-89, given in Appendix 4.

1. SELECTION AND PREPARATION OF CAST IRON SAMPLES

1.1. To determine the chemical composition of liquid cast iron, three samples are taken from each outlet from the furnace with a uniform stream from the chute: at the beginning, in the middle and at the end of the outlet.

1.2. When draining metal, three samples are taken from each ladle: after draining about 1/4, 1/2 and 3/4 of the ladle.

1.3. The sample is taken with a spoon or probe by immersion in liquid metal or under a stream of metal.

1.4. The mass of the sample for chemical analysis should be 0.1-1 kg, for spectral analysis - at least 0.05 kg.

1.5. The metal is poured into the mold. The design and dimensions of molds for chemical analysis are shown in Figures 1-6, for spectral analysis - Figures 1, 7 of Appendix 1.

It is also possible to use other molds that ensure the required accuracy of the analysis results.

(Changed edition, Amendment No. 2).

1.6. When pouring, underfilling, overfilling, splashing and splashing of metal, and interruption of the stream are not allowed.

1.7. The sample in the mold should solidify calmly.

1.8. After cooling, the sample is removed from the mold and marked with the number of the furnace, outlet and ladle (when casting pig iron).

1.9. The sample must be free of holes, cracks, joints and slag inclusions. The sample for chemical analysis may be annealed.

1.10. The sample surface in the places where chips or pieces are taken is thoroughly cleaned of sand, oxides and casting crust. The sample for spectral analysis is ground onto a plane. Holes, cracks, slag inclusions and tarnished colors that are visible to the naked eye are not allowed on the treated surface.

(Changed edition, Amendment No. 2).

1.11. To take samples in the form of chips, drills with a cutting edge angle of 120° made of high-speed steel or hard alloy with a diameter of 10-20 mm are used.

1.12. The chips are taken by drilling at low speed in the middle part of the sample, avoiding the formation of dust. Drilling is carried out without cooling the drill. The chips should be no more than 0.4 mm thick.

1.11, 1.12. (Changed edition, Amendment No. 1).

1.13. A sample of cast iron, which cannot be drilled, is broken and small pieces are separated from the surface of the chip.

1.14. The same mass of cast iron is taken from each sample.

Samples in the form of a piece or shavings are crushed to a grain size of no more than 0.2 mm, after which they are combined, averaged and reduced by quartering to a mass of at least 20 g.

For cast iron intended for export, the sample weight must be at least 100 g.

1.15. When pouring liquid metal into a mold (Fig. 7), it is allowed to use a sample in the form of rods or disks for chemical analysis. When taking three samples from a ladle, pieces of three rods of equal weight or size are crushed. For spectral analysis, a sample in the form of disks is used.

1.16. The sample prepared for chemical analysis is placed in a closed container.

1.17. The sample to determine the chemical composition is stored for 3 months. It is allowed to set a different storage period for the sample when using cast iron inside the enterprise.

1.18. When determining the chemical composition of pig iron, the number of selected pigs is regulated in the regulatory and technical documentation for specific products.

(Changed edition, Amendment No. 2).

1.19. When sampling pig iron intended for export, at least one pig iron from every 3 tons is taken from a stack or wagon.

1.20. Selected pigs are marked, indicating the number of the stack or car.

1.21. The surface of the pigs at the sampling sites is thoroughly cleaned of sand, slag and foundry crust. A sample in the form of chips is taken from the side surface, cleaned according to clause 1.10, at a right angle to the long axis of the pig. The chips obtained after drilling to a depth of 4-6 mm are discarded, and drilling is completed at the same distance from the opposite side of the pig. For analysis, use chips collected after drilling to a depth of more than 4-6 mm and prepared in accordance with paragraphs 1.12 and 1.14. A sample for analysis of cast iron that cannot be drilled is taken and prepared in accordance with paragraphs 1.13 and 1.14.

(Changed edition, Amendment No. 2).

2. SELECTION AND PREPARATION OF BUCKET SAMPLES OF STEEL AND ALLOYS

2.1. To determine the chemical composition of open-smelted steels and alloys, one to three samples are taken from each ladle. Two samples are taken after approximately half of the ladle metal has been poured. One sample is taken if it is possible to use the remaining sample metal for re-analysis. A second sample is taken for re-analysis.

Three samples are taken after draining 1/4, 1/2 and 3/4 of the ladle.

When casting ingots consisting of one or more heats, samples are taken at the beginning or end of casting of each ladle. When casting melts of a small mass into one siphon, a sample is taken at the beginning or end of casting.

When casting melts of small mass under vacuum or in a protective atmosphere, one sample is taken at the beginning or end of casting.

On automatic molding lines with stationary casting of metal from ladles with a capacity of up to 30 tons, it is allowed to take samples before the start of casting.

When ladleless casting of metal from an open induction furnace, it is allowed to take a sample directly from the furnace crucible before starting casting.

2.2. To determine the chemical composition of steel and alloy melts from continuous or semi-continuous casting plants, one sample is taken in the middle of casting each ladle. It is allowed to take a sample from the workpiece cast in the middle of the casting of each ladle. In installations not equipped with a tundish, it is allowed to take a sample at the end of casting. In installations with extra-furnace evacuation, it is allowed to take a sample from the crystallizer.

2.1, 2.2

2.3. The chemical composition of steels and alloys of electroslag, vacuum-arc, plasma-arc and electron-beam remelting is determined by a sample taken from the ladle of the initial melt, with the exception of elements whose content changes during remelting and which are established by the regulatory and technical documentation for specific products.

2.4. To determine the chemical composition of steel and alloys of vacuum-induction smelting, as well as steel of electroslag, vacuum-arc, electron-beam and plasma-arc remelting by elements, the content of which changes during remelting and which are established by the regulatory and technical documentation for specific products, samples are taken from ingots, conversion metal or finished rolled products, as indicated in Section 3.

To determine the chemical composition of steel and alloys smelted in vacuum induction furnaces, it is allowed to take a metal sample from the furnace crucible before starting casting.

(Changed edition, Amendment No. 1).

2.5. When electroslag remelting of electrodes from two initial melts using the pairwise assembly method, the chemical composition of steel and alloys of electroslag remelting is established as the arithmetic mean of the results of determining the elements in a sample of the original melts.

2.6. The sample is taken with a heated spoon, filled under a stream, or with a probe immersed in liquid metal. It is allowed to pour metal into the mold using a throttled stream directly from the ladle.

For difficult-to-cut steels and alloys, sampling by granulation or scrap is allowed.

(Changed edition, Amendment No. 2).

2.7. Schemes of molds for sampling and probes of a one-time sampling device are shown in Figures 1-3, 5, 8-10 of Appendix 1.

2.8. The sample weight for chemical analysis should be 0.3-2.0 kg, for spectral analysis - 0.06-1.0 kg. It is allowed to use the same sample for chemical and spectral analysis.

2.7, 2.8. (Changed edition, Amendment No. 1).

2.9. When pouring metal into a mold, underfilling and overfilling, splashing and splashing of metal, and interruption of the stream are not allowed.

2.10. The metal in the mold should solidify calmly. To deoxidize unsettled steel, aluminum with a purity of at least 99% is added to the sample based on its mass fraction in the sample of no more than 0.2%. When determining aluminum, silicocalcium, ferrosilicon, ferromanganese and other deoxidizing agents that do not contain aluminum are used.

(Changed edition, Amendment No. 2).

2.11. Cooled metal samples are released from the molds. It is allowed to cool samples by blowing compressed or fan air, as well as in water. The sample temperature before immersion in water should not exceed 500 °C.

2.12. The sample is marked with the number of the heat, ladle and serial number of the sample. The height of the numbers for the stamp should be 5-10 mm. It is allowed to use other methods of sample labeling that ensure its clarity and safety.

2.13. The sample should be dense, without cracks, cavities, or visible slag inclusions. There are no burrs, films, belts from interruption of the jet during casting, or deposits in the upper part of the sample allowed on the surface of the sample.

2.14. Samples may be forged and annealed.

2.15. The metal surface at the sampling sites in the form of chips is cleaned of slag, mechanical impurities, and scale.

2.16. A sample in the form of steel chips is taken by milling, turning, planing the entire cross-section of the sample or by drilling the middle of one of the side surfaces to a depth to the longitudinal axis of the sample. The sample is taken without lubrication. It is allowed to use distilled water for cooling. The surface of the chips should not have tarnish.

2.17. Short chips no more than 0.4 mm thick are thoroughly mixed. The prepared sample is placed in a sealed container. The sample weight should be 20-100 g.

(Changed edition, Amendment No. 1).

2.18. For spectral analysis, cut off the lower part of the sample at a distance of 1/3 of the height. Uncut samples may be used. A layer 1.5-2.0 mm thick is ground off from the bottom of the sample, and for samples taken with a one-time sampling device, a layer of 0.5-1.0 mm is removed from one of the sample planes.

On the treated surface of the sample, holes, slag inclusions, as well as mechanical processing defects, cracks and tarnished colors are not allowed to be visible to the naked eye.

(Changed edition, Amendment No. 1, 2).

2.19. The sample is stored for at least 3 months. When using steels and alloys within an enterprise, it is allowed to set a different shelf life.

3. SELECTION AND PREPARATION OF SAMPLES TO DETERMINE THE CHEMICAL COMPOSITION OF FINISHED ROLL STAND

3.1. The chemical composition of melted steel and alloys, if necessary, is determined by a sample taken from ingots, continuously cast billets, forged metal or rolled products.

Sampling is carried out from an ingot or continuously cast billet corresponding to the middle of the melt, by drilling or cutting a piece of metal from the middle part of the ingot to a depth of 50-70 mm.

3.2. To determine the chemical composition of steel and open-smelting alloys, at least three rolled units are selected. One sample is taken from a selected unit of rolled or forged metal.

3.3. To determine the chemical composition of the metal of vacuum induction melting, a sample is taken from one or more ingots, pig blanks, and finished rolled products; for metal, vacuum-arc and electroslag remelting - from ingots, conversion billets or finished rolled products obtained from metal of one initial melt by remelting according to the same mode.

For metal of vacuum-induction smelting and vacuum-arc remelting, samples are taken from the upper part, for electroslag remelting - from the lower part of the ingot or the corresponding conversion billets or finished rolled products. For electroslag remelting ingots smelted using the arcless feeding method, samples are taken from the upper part of the ingot.

(Changed edition, Amendment No. 2).

3.4. A sample in the form of chips for chemical analysis is taken from a sample or directly from a controlled unit of rolled product, billet, or ingot.

Before selecting chips for chemical analysis, the metal surface is thoroughly cleaned of scale and mechanical impurities. When decarburizing or carburizing steel, the surface is cleaned until the specified layers are completely removed.

3.5. For ingots, rolled and forged billets, as well as for forgings, sections, shapes, strip products and seamless pipes, chips are selected in one of the following ways:

- processing the entire cross-section of rolled products or a symmetrical half of it;

- by drilling a cross section along the rolling direction at a distance of 1/2 of the radius, 1/4 of the diagonal from the surface or 1/2 of the pipe wall thickness in accordance with Figure 1 of Appendix 2;

- by drilling one of the side surfaces to a depth to the middle of the sample in accordance with Figure 2 of Appendix 2;

By drilling the cross section in accordance with Figure 3 of Appendix 2 for forgings with a diameter or square side of more than 500 mm.

For rolling small sections, drilling through is allowed, while in shaped profiles they drill in the middle of the flange width or 1/4 of the profile height in accordance with Figure 4 of Appendix 2.

For large shaped profiles, machining the entire cross section can be replaced by drilling at different points along the entire cross section with an even distribution and the same drilling depth.

3.6. For thick-sheet, wide-band steel, seamless and welded pipes with a wall thickness of 4 mm or more, a sample is taken by drilling at three points, for thicknesses up to 50 mm inclusive - the entire thickness, for thicknesses more than 50 mm - up to half the thickness.

For sheets and strips, drill at a distance of 10-15 mm from the edge, in the middle of the width and in the middle between the two indicated points.

For welded pipes, drill at a distance of 20-25 mm from the seam at a point diametrically opposite to the seam, and in the middle between the two indicated points.

3.7. For thin-sheet steel, strips, seamless and welded pipes with a wall thickness of less than 4 mm, chips are taken by processing over the entire cross-section of a sample cut from a sheet or strip across the rolling direction, or a piece of pipe.

Before processing, a sample or a piece of pipe is cut into several parts or bent into several layers and compressed.

For sheets with a thickness of 1 mm or more, as well as pipes with a wall thickness of 1 mm or more, it is allowed to take a sample in accordance with clause 3.6 instead of processing the cross-section of the sample.

3.8. The sample is cut from the steel wire at a distance of 10-15 mm from the end of the coil.

The sample is crushed by planing, milling or chopping along the entire cross section.

3.9. If disagreements arise in the assessment of the chemical composition, a sample is taken by processing the entire cross-section of the rolled product or a symmetrical half of it.

3.10. The amount of chips taken in each place should be approximately the same.

Wood shavings taken from different places or from different rolled units are combined, mixed and reduced by quartering to a weight of 20-100 g.

3.11. Samples for spectral analysis in the form of a transverse template 60 mm wide are taken from each controlled rolled unit: from sheets with a thickness of 1 to 40 mm, long rolled products with a diameter or square side of up to 250 mm, angles No. 2-14, beams No. 10-36, channels N 5-30.

3.12. For sheet and wide-band steel, samples are cut from half of the template:

for sheets with a thickness of 4 mm or less - one sample measuring 40x40 mm in accordance with drawing 1 of Appendix 3;

for sheets with a thickness of more than 4 mm - three samples measuring 40x30 mm at the edge, middle and 1/2 half-width in accordance with drawing 2 of Appendix 3. For sheet thickness from 4 mm to 6 mm - drawing 1 or 2 of Appendix 3.

3.11, 3.12. (Changed edition, Amendment No. 2).

3.13. For long products with a diameter or a square side of up to 50 mm, use the entire cross-section of the template in accordance with Figures 3, 4 of Appendix 3. For long products or a square side of more than 50 mm, a sample 40 mm wide is cut from the template symmetrically to the diameter or diagonal length through the entire cross-section of the template in accordance with Figures 5, 6 of Appendix 3. Depending on the size of the template, it is possible to cut the sample into several parts.

(Changed edition, Amendment No. 1, 2).

3.14. For shaped rolled products, half of the transverse template is used. Depending on the size of the rental, it is possible to cut the sample into several parts in accordance with Figures 7-9 of Appendix 3.

3.15. Samples for spectral analysis for sheets with a thickness of less than 4 mm are processed from the surface of the sheet; for sheets with a thickness of more than 4 mm, as well as for long and shaped rolled products, the cross section is processed. For sheets with a thickness of 4 to 6 mm, surface treatment of the sheet is allowed. On the treated surface of the sample, holes, slag inclusions, as well as mechanical processing defects, cracks and tarnished colors are not allowed to be visible to the naked eye.

(Changed edition, Amendment No. 2).

3.16. On the treated surface of each sample, spectral analysis is performed at two or three points indicated in the drawing. The search spots are located at a distance of at least 10 mm from the edge of the profile or cutting sheet. For long products, the search spots are located along the diameter or diagonally. One search spot should fall in the center of the profile. For sheet and shaped rolled products, search spots are located throughout the entire thickness of the profile in accordance with Figures 10, 11 of Appendix 3. The measurement results are averaged for each rolled unit.

3.17. If the area of the search spot is larger than the sharpened cross-section of the profile, then the surfaces adjacent to it, parallel to the rolling direction, are also cleaned.

Damn.1. Mold with truncated cone shape

Damn.1

Damn.2. Mold with the shape of a truncated tetrahedral pyramid

Mold with the shape of a truncated tetrahedral pyramid

Damn.3. Combined mold with truncated cone shape

Combined mold with truncated cone shape

Material: 1 - copper; 2, 3, 4, 5 - steel

Damn.4. Mold with a prism shape

Mold with a prism shape

Damn.4

Damn.5. Mold with truncated cone shape

Mold with truncated cone shape

Material - cast iron or steel

Damn.6. Mold

Mold

Damn.6

Damn.7. Double disc mold for cast iron sampling

Double disc mold for cast iron sampling

Material - cast iron or copper. Sample thickness - 4-6 mm

Damn.8. Detachable probe for sampling liquid steel

Material - steel

Damn.9. Detachable probe for sampling liquid steel

Detachable probe for sampling liquid steel

Material - steel

Damn.10. Detachable probe for sampling liquid steel

Detachable probe for sampling liquid steel

Material - steel

Damn.10

APPENDIX 1. (Changed edition, Amendment No. 1, 2).

APPENDIX 2 (mandatory). SCHEME FOR SAMPLING FROM BLANKETS, FORGINGS AND ROLL STANDS FOR CHEMICAL ANALYSIS

APPENDIX 2
Mandatory

Damn.4

APPENDIX 3 (mandatory). SCHEMES FOR SAMPLING FROM BILLETS AND FINISHED ROLLED PRODUCTS FOR SPECTRAL ANALYSIS

APPENDIX 3
Mandatory

Part 2. Samples for determination of chemical composition

ISO 377-2-89

1. Purpose

1.1. This standard establishes methods for obtaining samples to determine the chemical composition of steel, with the exception of determining the hydrogen content.

Samples are intended to be tested, which (unless otherwise agreed between the parties concerned) are carried out in accordance with the methods specified in the product standard or, in the absence of one, in the test standard.

To compare with the technical specifications, a sample with an average chemical composition is selected.

Methods for determining chemical composition are divided into two groups:

a) chemical methods involving the entry of the sample into a chemical reaction (see clause 5);

b) physical methods involving the determination of constituent elements without a chemical reaction (see clause 6).

1.2. This standard applies to raw products*, semi-finished and forged steel products covered by ISO 404-81 and does not apply to samples of smelting or refining products. Where product standards or test standards specify different conditions, those different conditions apply.
_______________
* In relation to this standard, the concept of “raw products” includes not only metal ingots, but also rolled products: blooms, slabs and billets of other profiles.

ISO 377-1-89 Selection and preparation of specimens and samples for testing of forged steel. Part 1. Samples and tests for mechanical tests

ISO 404-81 Steel and steel products. General technical delivery conditions

3. Terms

3.1. Product sample: a product (for example, a sheet) selected from a batch for the preparation of samples.

3.2. Sample: A specified quantity of solid material taken from a sample product as a sample for analysis (see 3.3).

3.3. Sample for analysis: a specified amount of material taken from a sample or directly from a product that maintains the average chemical composition of the product.

Samples are divided into the following categories:

samples in the form of chips (see Section 5);

solid samples (see clause 6.1);

pressed samples (see clause 6.3);

remelted samples (see clause 6.4).

3.4. Weighed and collected sample: part of the sample to be analyzed or the entire sample taken for analysis.

Note. Alternative sample preparation methods are shown in the drawing for information only.

4. Sampling and preparation

4.1. Sampling locations and sizes

Samples may only be taken at locations specified in the product standard.

In the absence of appropriate requirements in the product standard or manufacturer's specifications, samples for analysis should be taken from specimens or samples intended for mechanical testing (see 5.1 of ISO 377-1) or taken directly from the product. In this case, samples of round bars of full and incomplete profile are cut from one end of the workpiece along the cross section.

The dimensions of the samples must be sufficient to allow repeated tests, if necessary.

4.2. Sample identification

Samples must be identified by identification markings to enable identification of the product from which they were taken and the location of collection.

4.3. Sample surface preparation

All coatings or contaminants (eg scale or grease) must be removed from the surface of the specimen by any suitable means. If necessary, the surface must be degreased with an appropriate solution.

If the chemical composition of the product surface tends to change, then the corresponding part of the sample surface can be removed.

After these operations, the sample must be protected from contamination.

4.4. Storing Samples for Analysis

To avoid contamination or any alteration, samples should be stored in completely dry containers made of chemically inert materials with high abrasion resistance to steel.

Containers must be appropriately labeled and, if necessary, sealed. Containers in which samples subject to arbitration examination are stored must be sealed by the manufacturer and recipient or their representatives.

In the absence of a special agreement, storage of containers is the responsibility of the party responsible for sampling.

The numbers indicate the corresponding points in the text.

5. Selection and preparation of samples in the form of chips to determine the chemical composition using chemical analysis methods

5.1. Machining and cutting

All instruments, machines and containers used for sample preparation must be pre-cleaned to prevent any contamination of samples for analysis.

Planing, milling, turning or cutting are used to take samples across the entire cross-section of the product.

If samples are taken not over the entire cross-section, but in individual places, drilling or one of the specified types of metal processing is usually used.

The use of cutting lubricants is permitted only in exceptional cases. In this case, the chips must be cleaned with any solution that does not leave residue.

When machining the product, oxidation and overheating of the chips are not allowed. The inevitable development of chip tarnish due to heat when machining some manganese and austenitic steels must be minimized by proper selection of cutting tools and cutting speeds.

As a result of cutting, small chips should be obtained of such a size that they do not have to be additionally crushed in accordance with the requirements of paragraph 5.2.1 during the preparation of samples for analysis.

The size of the chips should be such that the mass of each chip is from 2.5 to 25 kg.

For unalloyed and low-alloy steels, the chips should have a mass of about 10 mg, for high-alloy steels - about 2.5 mg.

If carbon steel is tested, the chips should be as continuous and compact as possible (about 100 mg) to prevent chipping and loss of graphite. Chips obtained as a result of mechanical processing of metal are not suitable for determining the oxygen content.

5.2. Grinding and sifting

5.2.1. Grinding

If the chips obtained in accordance with clause 5.1 are not suitable for testing, they are crushed using a pre-cleaned crusher.

If this grinding is not suitable, one of the cutting types is used.

5.2.2. Screening

If sieving is necessary to obtain the desired sample, then all the chips are sifted through a sieve with holes with a diameter of 2.5 mm.

If necessary, the unsifted chips are re-crushed and sifted again.

If the sample contains dust, i.e. chips that pass through a sieve with holes 0.050 mm in diameter, then this dust must be separated by sieving, and the two fractions thus obtained are weighed. In this case, the sample will consist of two parts proportional to these fractions.

To determine the carbon content, take a whole sample sifted through a sieve with holes 2.5 mm in diameter.

To determine the nitrogen content, the sample is mechanically processed so that there are as few individual particles smaller than 0.050 mm as possible.

Screening should be carried out taking all necessary precautions to avoid contamination, alteration and loss of material.

5.3. Sample weight for analysis

The sample mass must be sufficient to allow repeated tests, if necessary. The amount of material obtained for analysis is determined by weighing. A mass of about 100 g is considered sufficient.

5.4. Storing Samples for Analysis

Samples are stored in accordance with the requirements of clause 4.4.

It is allowed to store samples for analysis in the form of a solid mass and prepare shavings as needed.

6. Selection and preparation of solid, pressed or melted samples to determine the chemical composition using physical methods of analysis

(Emission spectrometry in visible and ultraviolet spectral regions, X-ray fluorescence, mass spectrometry, etc.).

Depending on the requirements of the product standard or by agreement of interested parties, the following are used for testing:

a) solid sample;

b) pressed or melted sample.

Note. Not all grades of steel can be pressed and remelted.

To carry out the analysis, a small portion of the sample is taken. The volume of test material is selected in accordance with the method of analysis.

6.1. Solid sample

A solid sample is obtained by separating such a part of the material from the workpiece that can be placed on a special table or secured in the sample holder of an analytical instrument.

The separation of the sample is carried out by sawing, planing, cross-cutting, shearing or stamping.

The surface of the sample is ground, milled or sandpapered to the cleanliness required for the appropriate analysis. To treat the sample surface before determining the silicon content by X-ray fluorescence analysis or emission spectrometry, alumina is used as an abrasive material. Before determining the aluminum content using the same methods, the surface of the sample is treated with silicon abrasive. When determining carbon content by emission spectrometric analysis, an oxide-based abrasive is used to treat the surface of the sample.

In the absence of any specification in the product standard, a portion of the sample corresponding to the cross-section of the product is selected for analysis if the sample is of sufficient thickness.

6.2. Solid sample less than 1.5 mm thick

Some physical analysis methods produce an electric arc or spark between a solid sample and an electrode (visible-ultraviolet emission spectrometry or mass spectrometry), which heats the solid sample. The thinner the sample, the greater the local heating.

For solid samples less than 1.5 mm thick, it may be necessary to use special technology to reduce local heating from sparking. For example, the edges of a solid sample can be welded* to a small steel plate, or one side of the sample can be layered with tin and the other side left free.
_______________
* The method of autogenous welding with a tungsten electrode in an inert gas environment is used.

Then the surface must be treated as specified in paragraph 6.1.

6.3. Pressed sample

The preparation of chips is carried out using the same methods and under the same conditions as for samples intended for analysis by chemical methods (see paragraphs 5.1 and 5.2).

Approximately 10 g of fine chips of regular shape are placed inside a metal ring with an internal diameter of about 25 mm. This ring is placed on a solid steel base with a completely flat, well-polished top surface. A press with a plunger that fits freely into the ring with little friction produces a compressive force of at least 1800 MPa*.
_______________
* 1 MPa = 1 N/mm = 10 bar.

Then the surface of the sample with the ring pressed into one piece is processed as indicated in paragraph 6.1. After this, the sample is analyzed using physical methods.

The surface quality of the analyzed sample depends to a certain extent on the shape and size of the chips. Do not use chips that are too small to pass through a sieve with holes less than 0.80 mm in diameter.

The calibration curves of the analytical instrument are drawn based on the results of the analysis of pressed samples.

6.4. Remelted sample

Chips, solid samples or small pieces of steel can be melted under inert gases in special melting apparatus, such as a high-frequency or argon-arc furnace, to give them a shape suitable for spectral analysis.

It is important that any quantitative chemical changes in the melted material are recorded and that they do not have a significant impact on the test results.

Note. To minimize changes in the chemical composition of the remelted material, 0.05 g of zirconium is often added to it as a deoxidizing agent, and the analytical device is calibrated based on the results of testing standard remelted samples.

APPENDIX 4. (Introduced additionally, Amendment No. 2).

Electronic document text
prepared by Kodeks JSC and verified against:
official publication
Ordinary carbon steel
quality and low alloy: Sat. GOST. -
M.: Standartinform, 2009

1.8 . After cooling, the sample is removed from the mold and marked with the number of the furnace, outlet and ladle (when casting pig iron).

2. SELECTION AND PREPARATION OF BUCKET SAMPLES OF STEEL AND ALLOYS

by drilling one of the side surfaces to a depth to the middle of the sample in accordance with Fig. applications;

by drilling the cross section in accordance with the drawing. applications for forgings with a diameter or square side greater than 500 mm.

For rolling small sections, drilling through is allowed, while in shaped profiles they drill in the middle of the flange width or 1/4 of the profile height in accordance with the drawing. applications.

For large shaped profiles, machining the entire cross section can be replaced by drilling at different points along the entire cross section with an even distribution and the same drilling depth.

for sheets with a thickness of more than 4 mm - three samples of size 40´ 30 mm at the edge, middle and 1/2 half-width in accordance with drawing. applications. With a sheet thickness from 4 mm to 6 mm - damn. or applications.

3.11, 3.12. (Changed edition, Amendment No. 2).

Mold with the shape of a truncated tetrahedral pyramid

A = 34 ´ 34

b= 22 ´ 22

Combined mold with truncated cone shape

Material: 1 - copper; 2, 3, 4, 5 - steel

Mold with a prism shape

Mold with truncated cone shape

Material - cast iron or steel.

Mold

Double disc mold for cast iron sampling

Material: cast iron or copper. Sample thickness - 4 - 6 mm.

Detachable probe for sampling liquid steel

(Changed edition, Amendment No. 1,).

APPENDIX 2

Mandatory

SCHEME FOR SAMPLING FROM BLANKETS, FORGINGS AND ROLLED WORKS
FOR CHEMICAL ANALYSIS

APPENDIX 3

Mandatory

SCHEMES FOR SAMPLING FROM BILLETS AND FINISHED ROLLED PRODUCTS FOR SPECTRAL ANALYSIS

b) physical methods involving the determination of constituent elements without a chemical reaction (see paragraph).

Numbers indicate corresponding points in the text

It is allowed to store samples for analysis in the form of a solid mass and prepare shavings as needed.

6 . Selection and preparation of solid, pressed or melted samples for determination of chemical composition using physical methods of analysis

(Emission spectrometry in visible and ultraviolet spectral regions, X-ray fluorescence, mass spectrometry, etc.)

Depending on the requirements of the product standard or by agreement of interested parties, the following are used for testing:

a) solid sample;

b) pressed or melted sample.

Note: Not all grades of steel can be pressed and remelted.

To carry out the analysis, a small portion of the sample is taken. The volume of test material is selected in accordance with the method of analysis.

6.1 . Solid sample

A solid sample is obtained by separating such a part of the material from the workpiece that can be placed on a special table or secured in the sample holder of an analytical instrument.

The separation of the sample is carried out by sawing, planing, cross-cutting, shearing or stamping.

The surface of the sample is ground, milled or sandpapered to the cleanliness required for the appropriate analysis. To treat the sample surface before determining the silicon content by X-ray fluorescence analysis or emission spectrometry, alumina is used as an abrasive material. Before determining the aluminum content using the same methods, the surface of the sample is treated with silicon abrasive. When determining carbon content by emission spectrometric analysis, an oxide-based abrasive is used to treat the surface of the sample.

In the absence of any specification in the product standard, a portion of the sample corresponding to the cross-section of the product is selected for analysis if the sample is of sufficient thickness.

6.2 . A solid sample with a thickness of less than 1.5 mm.

Some physical analysis methods produce an electric arc or spark between a solid sample and an electrode (visible-ultraviolet emission spectrometry or mass spectrometry), which heats the solid sample. The thinner the sample, the greater the local heating.

For solid samples less than 1.5 mm thick, it may be necessary to use special technology to reduce local heating from sparking. For example, the edges of a solid sample can be welded* to a small steel plate, or one side of the sample can be layered with tin and the other side left free.

* 1 MPa = 1 N/mm 2 = 10 bar.

Then the surface of the sample with the ring pressed into one piece is processed as indicated in paragraph. After this, the sample is analyzed using physical methods.

The surface quality of the analyzed sample depends to a certain extent on the shape and size of the chips. Do not use chips that are too small to pass through a sieve with holes less than 0.80 mm in diameter.

The calibration curves of the analytical instrument are drawn from the results of the analysis of pressed samples.

6.4 . Remelted sample

Chips, solid samples or small pieces of steel can be melted under inert gases in special melting apparatus, such as a high-frequency or argon-arc furnace, to give them a shape suitable for spectral analysis.

It is important that any quantitative chemical changes in the material being melted are recorded and that they do not have a significant impact on the test results.

Note: To minimize changes in the chemical composition of the remelted material, 0.05 g of zirconium is often added to it as a deoxidizing agent, and the analytical device is calibrated based on the results of testing standard remelted samples.”

APPENDIX 4. (Entered additionally, Change No. 2 ).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Metallurgy

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated December 30, 1981 No. 5786

3. Appendix 4 of this standard was prepared by direct application of the international standard ISO 377-2-89 “Selection and preparation of specimens and samples for testing of forged steel. Part 2. Samples for determining the chemical composition"

4. INSTEAD GOST 7565-73

5. The validity period was removed by Decree of the State Standard of Ukraine dated June 17, 1991 No. 879

6. EDITION (September 2009) with Amendments No. 1, 2, approved in June 1986, June 1991 (IUS 9-86, 9-91)

. The metal is poured into the mold. The design and dimensions of cups-molds for chemical analysis are shown in Fig. - , for spectral analysis - damn. , recommended application .

It is also possible to use other molds that ensure the required accuracy of the analysis results.

(Changed edition, Amendment No. 2).

2. SELECTION AND PREPARATION OF BUCKET SAMPLES OF STEEL AND ALLOYS

by drilling one of the side surfaces to a depth to the middle of the sample in accordance with Fig. applications;

by drilling the cross section in accordance with the drawing. applications for forgings with a diameter or square side greater than 500 mm.

For large shaped profiles, machining the entire cross section can be replaced by drilling at different points along the entire cross section with an even distribution and the same drilling depth.

3.11, 3.12. (Changed edition, Amendment No. 2).

Mold with the shape of a truncated tetrahedral pyramid

A = 34 ´ 34

b= 22 ´ 22

Combined mold with truncated cone shape

Material: 1 - copper; 2, 3, 4, 5 - steel

Mold with a prism shape

Mold with truncated cone shape

Material - cast iron or steel.

Mold

Double disc mold for cast iron sampling

Material: cast iron or copper. Sample thickness - 4 - 6 mm.

Detachable probe for sampling liquid steel

(Changed edition, Amendment No. 1,).

APPENDIX 2

Mandatory

SCHEME FOR SAMPLING FROM BLANKETS, FORGINGS AND ROLLED WORKS
FOR CHEMICAL ANALYSIS

APPENDIX 3

Mandatory

SCHEMES FOR SAMPLING FROM BILLETS AND FINISHED ROLLED PRODUCTS FOR SPECTRAL ANALYSIS

b) physical methods involving the determination of constituent elements without a chemical reaction (see paragraph).

Numbers indicate corresponding points in the text

5 . Collection and preparation of samples in the form of chips for determination of chemical composition using chemical analysis methods

5.1 . Machining and cutting

All instruments, machines and containers used for sample preparation must be pre-cleaned to prevent any contamination of samples for analysis.

Planing, milling, turning or cutting are used to take samples across the entire cross-section of the product.

If samples are taken not over the entire cross-section, but in individual places, drilling or one of the specified types of metal processing is usually used.

The use of cutting lubricants is permitted only in exceptional cases. In this case, the chips must be cleaned with any solution that does not leave residue.

When machining the product, oxidation and overheating of the chips are not allowed. The inevitable development of chip tarnish due to heat when machining some manganese and austenitic steels must be minimized by proper selection of cutting tools and cutting speeds.

As a result of cutting, the chips should be small and of such a size that they do not have to be further grind in accordance with the requirements of paragraph. during sample preparation for analysis.

The size of the chips should be such that the mass of each chip is between 2.5 mg and 25 mg.

For unalloyed and low-alloy steels, the chips should have a mass of about 10 mg, for high-alloy steels - about 2.5 mg.

If carbon steel is tested, the chips should be as continuous and compact as possible (about 100 mg) to prevent chipping and loss of graphite. Chips obtained as a result of mechanical processing of metal are not suitable for determining the oxygen content.

5.2 . Grinding and sifting

5.2.1 . Grinding

If the chips obtained in accordance with paragraph are not suitable for testing, they are crushed using a pre-cleaned crusher.

If this grinding is not suitable, one of the types of cutting is used.

5.2.2 . Screening

If sieving is necessary to obtain the desired sample, then all the chips are sifted through a sieve with holes with a diameter of 2.5 mm.

If necessary, the unsifted chips are re-crushed and sifted again.

If the sample contains dust, i.e. chips that pass through a sieve with holes 0.050 mm in diameter, then this dust must be separated by sieving, and the two fractions thus obtained are weighed. In this case, the sample will consist of two parts proportional to these fractions.

To determine the carbon content, take a whole sample sifted through a sieve with holes 2.5 mm in diameter.

To determine the nitrogen content, the sample is mechanically processed so that there are as few individual particles smaller than 0.050 mm as possible. 6 . Selection and preparation of solid, pressed or melted samples for determination of chemical composition using physical methods of analysis

(Emission spectrometry in visible and ultraviolet spectral regions, X-ray fluorescence, mass spectrometry, etc.)

Depending on the requirements of the product standard or by agreement of interested parties, the following are used for testing:

a) solid sample;

b) pressed or melted sample.

Note: Not all grades of steel can be pressed and remelted.

To carry out the analysis, a small portion of the sample is taken. The volume of test material is selected in accordance with the method of analysis.

6.1 . Solid sample

A solid sample is obtained by separating such a part of the material from the workpiece that can be placed on a special table or secured in the sample holder of an analytical instrument.

The separation of the sample is carried out by sawing, planing, cross-cutting, shearing or stamping.

6.2 . A solid sample with a thickness of less than 1.5 mm.

* The method of autogenous welding with a tungsten electrode in an inert gas environment is used.

Then the surface must be treated as specified in paragraph 6.1. After this, the sample is analyzed using physical methods.

The calibration curves of the analytical instrument are drawn from the results of the analysis of pressed samples.

6.4 . Remelted sample

It is important that any quantitative chemical changes in the material being melted are recorded and that they do not have a significant impact on the test results.

APPENDIX 4. (Entered additionally, Change No. 2 ).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the USSR Ministry of Metallurgy

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated December 30, 1981 No. 5786

4. INSTEAD GOST 7565-73

5. The validity period was removed by Decree of the State Standard of Ukraine dated June 17, 1991 No. 879

6. EDITION (September 2009) with Amendments No. 1, 2, approved in June 1986, June 1991 (IUS 9-86, 9-91)