GOST 7565-81
GOST 7565−81 (ISO 377−2-89) Iron, steel and alloys. Sampling method for determination of chemical composition (with Amendments No. 1, 2)
GOST 7565−81
(ISO 377−2-89)
Group B09
INTERSTATE STANDARD
IRON, STEEL AND ALLOYS
Sampling method for determination of chemical composition
Iron, steel and alloys. Sampling for determination of chemical composition
ISS 77.080.01
AXTU 0809
Date of introduction 1982−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. Annex 4 of this standard prepared by the direct application of international standard ISO 377−2-89 «the Selection and preparation of specimens and samples for testing of forged steel. Part 2. Samples for determination of chemical composition"
4. REPLACE GOST 7565−73
5. The expiration time limit is removed by the Resolution of Gosstandart of the USSR from
6. EDITION (Sept 2009) with Changes No. 1, 2, approved in June 1986, and June 1991 (ICS 9−86, 9−91)
This standard specifies the method of sampling and preparation of samples for determining the chemical composition of pig iron, steel, alloys and finished steel.
Allowed the selection and preparation of samples forged steels for testing according to international standard ISO 377−2-89 given in Appendix 4.
(Changed edition, Rev. N 2).
1. SAMPLING AND SAMPLE PREPARATION OF CAST IRON
1.1. To determine the chemical composition of liquid pig iron from each issue from the furnace with a uniform stream from the discharge chute taken three samples: at the beginning, in the middle and at the end of the issue.
1.2. From each bucket when draining metal selected three samples: after draining, approximately ¼, ½ and ¾ of the bucket.
1.3. A sample is taken with a spoon or drobnica by immersion in a molten metal or under a stream of metal.
1.4. The sample mass for chemical analysis should be of 0.1−1 kg for spectral analysis — not less than 0.05 kg.
(Changed edition, Rev. N 1).
1.5. Metal is poured into the mold. The design and dimensions of the ingot for chemical analysis is shown in hell.1−6, for the spectral analysis features.1, 7 app 1.
Allowed to use other molds, to ensure the required accuracy of the analysis.
(Changed edition, Rev. N 2).
1.6. When casting is not allowed underfilling, overfilling, splashing and splashing of the metal, Proryv jet.
1.7. The sample in the mold should freeze safely.
1.8. After cooling, the sample is removed from the form, mark the number of the furnace, exhaust and bucket (the casting of iron into pigs).
1.9. The sample shall be without bowls, cracks, junctions and slag inclusions. A sample for chemical analysis allowed to anneal.
1.10. The surface of sample areas selection of chips or pieces should be carefully cleaned of sand, oxides and foundry cover. The sample for spectral analysis sharpen on the plane. On the treated surface are not permitted visible to the naked eye sinks, cracks, slag inclusions and color tint.
(Changed edition, Rev. N 2).
1.11. For the selection of the sample chip used the drill with the corner cutting edges 120° high-speed steel or hard alloy with a diameter of 10−20 mm.
1.12. Chips are taken by drilling at a slow speed in the middle part of the sample, preventing the formation of dust. Drilling is carried out without cooling of the drill. Chips should be of a thickness not exceeding 0.4 mm.
1.11, 1.12. (Changed edition, Rev. N 1).
1.13. A sample of cast iron, which is not amenable to drilling, breaking and separating the small pieces from the surface of the chip.
1.14. From each sample take the same mass of cast iron.
Samples in the form of a piece or shavings ground to a grain size not more than 0.2 mm, and then combined, averaged and reduced to kvantovanie mass of at least 20 g.
For cast iron intended for export, the sample mass should be at least 100 g.
1.15. When pouring the liquid metal into the mold (Fig.7) allowed for chemical analysis to use the sample in the form of rods or discs. When selecting from the ladle the three crushed samples of the same mass or size of the pieces of the three rods. For spectral analysis using a sample in the form of discs.
1.16. Prepared for chemical analysis a sample is placed in a sealable container.
1.17. A sample for determination of chemical composition stored for 3 months. It is allowed to set a different retention period of the sample during the application of cast within the enterprise.
1.18. In determining the chemical composition of pig iron in ingots, the amount of extracted pigs shall be regulated by normative-technical documentation for specific products.
(Changed edition, Rev. N 2).
1.19. When sampling iron in ingots, intended for export from the pile or wagon taken at least one pig from each of the 3 t
1.20. Selected pig label, indicating number of the pile or wagon.
1.21. The surface of the ingots in the places of sampling should be carefully cleaned of sand, slag and foundry cover. The sample in the form of chips taken from the lateral surface treated according to claim 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, swing, finish drilling at the same distance from the opposite side of the pig. For analysis using chips collected after drilling to a depth of 4−6 mm and prepared in accordance with the PP.1.12 and 1.14. A sample of cast iron, which is not amenable to drilling, selected and prepared in accordance with the PP.1.13 and 1.14.
(Changed edition, Rev. N 2).
2. THE SELECTION AND TRAINING OF LADLE SAMPLES OF STEEL AND ALLOYS
2.1. To determine the chemical composition of the melt steels and alloys melting open of each bucket are selected from one to three samples. Two samples are taken after pouring about half the metal bucket. One sample is taken, if it is possible to use the remaining metal samples for re-analysis. The second sample selected for re-analysis.
Three samples are taken after drain ¼, ½, and ¾ of the bucket.
The casting of ingots, consisting of one or more heats, samples are taken at the beginning or end of each pouring ladle. The casting of heats a small mass in one siphon a sample is taken at the beginning or end of the casting.
The casting of heats a small mass under vacuum or in a protective atmosphere selected one sample at the beginning or end of the casting.
On automatic molding lines with stationary casting metal from ladles with capacity up to 30 t allowed to sample before pouring.
When peskovskoe the casting metal from the open induction furnace is permissible to acquire a sample directly from the crucible before pouring.
2.2. To determine the chemical composition of heats of steels and alloys with installations continuous or semi-continuous casting of one sample taken in the middle of pouring each bucket. Allowed to acquire a sample from billets cast in the middle of pouring each bucket. In plants not equipped with intermediate bucket is allowed to acquire a sample at the end of pouring. In plants with secondary metallurgy vacuum, allowed to acquire a sample from the mold.
2.1, 2.2 (Amended, Rev. N 1, 2).
2.3. Chemical composition of steels and alloys electroslag, vacuum-arc, plasma-arc and electron beam remelting is set in the sample taken from the ladle smelting of the original, with the exception of elements whose content is changed during remelting and established normative and technical documentation for specific products.
2.4. To determine the chemical composition of steel and alloys in vacuum-induction smelting and steel electroslag, vacuum-arc, electron-beam and plasma-arc remelting the elements, the content of which varies during remelting and established normative and technical documentation for specific products, samples are taken from ingots of pig metal, or of finished steel, as specified in sec. 3.
Allowed to determine the chemical composition of steel and alloys melted in vacuum induction furnaces, to select a sample of metal from the crucible before pouring.
(Changed edition, Rev. N 1).
2.5. In electroslag remelting the electrodes of the two initial heats by the method of pair picking chemical composition of steel and alloys, electroslag remelting set as the arithmetic mean of the results of determination of elements in the sample of the original trunks.
2.6. A sample is taken of the heated spoon, fill under the tap, or drobnica, immersion in liquid metal. It is allowed to pour metal into a mold throttled stream directly from the bucket.
For hard steels and alloys allowed sampling granulation or scrutiny.
(Changed edition, Rev. N 2).
2.7. Diagrams of molds for sampling and drobnic single sampling device is shown in hell.1−3, 5, 8−10, Annex 1.
2.8. The sample mass for chemical analysis should be 0.3−2.0 kg for spectral analysis of the 0.06−1.0 kg is allowed to use the same sample for chemical and spectral analysis.
2.7, 2.8. (Changed edition, Rev. N 1).
2.9. When casting metal into a mold is not allowed underfilling and overfilling, splashing and spatter, Proryv jet.
2.10. The metal in the mold should freeze safely. For deoxidation of steel restless added to the sample, the aluminum purity of at least 99% of the calculation of its mass fraction in the sample is not more than 0.2%. In determining the use of aluminum silico-calcium, ferrosilicon, ferromanganese and other scavengers that do not contain aluminum.
(Changed edition, Rev. N 2).
2.11. Chilled samples of metal free from the molds. Allowed to cool the sample with compressed or fan air and in water. The temperature of the sample before immersion in water should not exceed 500 °C.
2.12. The sample marked number smelting, ladle and a sequence number of the sample. The height of the numbers for the stigma needs to be 5−10 mm. allowed to use other methods of marking of samples to ensure its clarity and integrity.
2.13. The sample shall be dense, free of cracks, holes, visible slag inclusions. On the surface of the sample are not allowed burrs, slivers, belts from the break jet in the case of casting, flows in the upper part of the sample.
2.14. Allowed the samples to forging and subjected to annealing.
2.15. The surface of the metal in the places of sampling in the form of chips are cleaned from slag, mechanical impurities, the dross.
2.16. The sample in the form of chips of steel were taken by milling, turning, planing the entire cross-sectional samples or drilling the middle of one of the side surfaces to a depth of the longitudinal axis of the sample. A sample taken without lubrication. Allowed to cool to use distilled water. The surface of the chip should not have a tint.
2.17. Short chips of a thickness not exceeding 0.4 mm are thoroughly mixed. The prepared sample is placed in a sealable container. The weight of the specimen should be 20−100 g.
(Changed edition, Rev. N 1).
2.18. For the spectrum analysis cut off the lower part of the sample at a distance of 1/3 of the height. Use the uncut sample. With the bottom of the sample grind off a layer thickness of 1.5−2.0 mm, and the samples taken one-time sampling unit, with one of the surfaces of the sample remove the layer of 0.5−1.0 mm.
On the treated surface of the sample are not permitted visible to the naked eye the shells, slag inclusions, and defects of mechanical processing, cracks and the color of the tint.
(Changed edition, Rev. N 1, 2).
2.19. The sample is stored for at least 3 months. Allowed in the application of steels and alloys in the factory to set a different retention period.
3. SELECTION AND PREPARATION OF SAMPLES FOR DETERMINING THE CHEMICAL COMPOSITION OF FINISHED STEEL
3.1. Chemical composition of melting steel and alloys, if necessary, determined by the sample selected from the ingots, continuous cast billets, forged metal or rolled.
Sampling is carried out from the ingot or slab corresponding to the middle of melting, drilling or cutting pieces 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 alloy smelting open select at least three units of hire. From selected units rolled or forged of metal taken one sample.
3.3. To determine the chemical composition of metals vacuum induction melting the alloy selected from one or more ingots, rerolling billets, units of finished rolled products; for metal, vacuum arc and electroslag remelting — from ingots, rerolling billets, or units of finished products obtained from one source metal melting remelting on the same regime.
For metal vacuum-induction melting and vacuum arc remelting samples are taken from the top, electroslag remelting from the bottom of the ingot, or their respective steelmaking semi-finished or finished products. For ingots electroslag remelting, melted at bezuhova method of feeding the sample is collected in the upper part of the ingot.
(Changed edition, Rev. N 2).
3.4. The sample in the form of chips for chemical analysis take from the sample or directly from the monitored unit rental, billet, ingot.
The surface of the metal prior to selection chip for chemical analysis is carefully cleaned from slag and mechanical impurities. When decarburization or carburizing steel surface cleaned to remove these layers.
3.5. For ingots, rolled and forged billets, and forgings, sections, shapes, bars and seamless pipe chip select one of the following:
— processing of all cross-section rolled or symmetrical half thereof;
— drilling cross-section along the direction of rolling at a distance of ½ radius ¼ the diagonal from the surface or ½ of the wall thickness of the pipe in accordance with the devil.1 of Annex 2;
— drilling one of the lateral surfaces to a depth to mid-sample in accordance with the devil.2 of Annex 2;
— drilling cross-section in accordance with the devil.3 of Annex 2 for forgings with a diameter or a side of a square more than 500 mm.
For rolling small sections is allowed drilling through, with shaped profiles drilled in the middle of the flange width or ¼ of the height of the profile in accordance with the devil.4 of Annex 2.
For a major profile handling the entire cross-section may be replaced by drilling at various points throughout the cross section with uniform distribution and uniform drilling depth.
3.6. For the plate, wide steel, seamless and welded pipes with a wall thickness of 4 mm or more samples were taken by drilling at three points, while for thicknesses up to 50 mm inclusive, the entire thickness, for thicknesses over 50 mm, up to half the thickness.
For sheets and strips drilled at a distance of 10−15 mm from the edge, in the middle of the width and in the middle between two specified points.
For welded pipe is drilled at a distance of 20−25 mm from the seam at a point diametrically opposite the seam, and in the middle between two specified points.
3.7. For sheet steel, strips, seamless and welded pipes with wall thickness less than 4 mm chips take processing over the entire cross section of the samples cut from sheet or tape across the direction of rolling, or cut the pipe.
Before processing the sample or a section of pipe is cut into several pieces or bent in multiple layers and compress.
For sheets with a thickness of 1 mm, and pipes with a wall thickness of 1 mm or more Pets instead of processing the cross section of the sample to select a sample in accordance with clause 3.6.
3.8. From steel wire samples cut at a distance of 10−15 mm from the end of the strand.
The sample is ground by planing, milling or cutting across the cross section.
3.9. If there is disagreement in the assessment of the chemical composition of the sample is taken treatment of all of the cross-section of rental or a symmetric half of it.
3.10. The number of chips taken at each location should be approximately the same.
Shavings, taken in different places or from different units of hire, join, mix and cut method Kvantovaya to the weight of 20−100 g.
3.11. Samples for spectral analysis in the form of transverse investigated template with a width of 60 mm is taken from each of the controlled rental units from sheets with a thickness of 1 to 40 mm long steel diameter or side of square to 250 mm, corners of 2−14 N, N 10−36 beams, channels N is 5−30.
3.12. For plates and wide strips of steel cut out half of the investigated template samples:
for sheets with a thickness of 4 mm and at least one sample of size 40 x 40 mm in accordance with the devil.1 of Annex 3;
for plates thicker than 4 mm — three samples with a size of 40x30 mm at the edge, middle and ½ of the half-width in accordance with the devil.2 of Annex 3. When the sheet thickness from 4 mm to 6 mm — hell.1 or 2 of Annex 3.
3.11, 3.12. (Changed edition, Rev. N 2).
3.13. For rolled sections with a diameter or a side of a square to 50 mm is used all the investigated template section in accordance with the devil.3, 4 of Annex 3. For rolled sections or a side of a square more than 50 mm from the investigated template cut out a sample width of 40 mm symmetrically to the diameter or the diagonal length through all the cross section of the investigated template in accordance with the devil.5, 6. of Annex 3. Depending on the size of the investigated template is allowed to cut the sample into several parts.
(Changed edition, Rev. N 1, 2).
3.14. For sections use of half cross the investigated template. Depending on the size of the rental allowed to cut the sample into several parts in accordance with the devil.7−9 of Annex 3.
3.15. Samples for spectral analysis for sheets with a thickness less than 4 mm from the treated surface of the sheet, for sheets with thickness more than 4 mm for long products and sections treated with a cross-section. For sheets with thickness from 4 to 6 mm allow for the processing of the surface of the sheet. On the treated surface of the sample are not permitted visible to the naked eye the shells, slag inclusions, and defects of mechanical processing, cracks and the color of the tint.
(Changed edition, Rev. N 2).
3.16. On the treated surface of each sample perform the spectral analysis in two or three points specified on the drawing. Sparking spot located at a distance of at least 10 mm from the edge of the profile or sheet cutting. For long products spot sparking a diameter or diagonal. One spot sparking must get to the center of the profile. For sheet and structural shapes spots sparking across a thickness profile in accordance with the devil.10 and 11 of Annex 3. The measurement results averaged for each unit of hire.
3.17. If the stain is sparking larger sharpened cross section of the profile strip and the adjacent surface parallel to the direction of rolling.
ANNEX 1 (recommended). DIAGRAMS OF MOLDS FOR SAMPLING
ANNEX 1
Recommended
Damn.1. Mold with the shape of a truncated cone
Mold with the shape of a truncated cone
Damn.1
Damn.2. Mold with the shape of a truncated four-sided pyramid
Mold with the shape of a truncated four-sided pyramid
Damn.2
Damn.3. The combined mold with the shape of a truncated cone
The combined mold with the shape of a truncated cone
Material: 1 — copper; 2, 3, 4, 5 — steel
Damn.3
Damn.4. Mold with the shape of the prism
Mold with the shape of the prism
Damn.4
Damn.5. Mold with the shape of a truncated cone
Mold with the shape of a truncated cone
Material — cast iron or steel
Damn.5
Damn.6. Mold
Mold
Damn.6
Damn.7. Double disc mold for sampling of cast iron
Double disc mold for sampling of cast iron
Material — cast iron or copper. Sample thickness is 4−6 mm
Damn.7
Damn.8. Drobnica split for sampling of liquid steel
Drobnica split for sampling of liquid steel
Material — steel
Damn.8
Damn.9. Drobnica split for sampling of liquid steel
Drobnica split for sampling of liquid steel
Material — steel
Damn.9
Damn.10. Drobnica split for sampling of liquid steel
Drobnica split for sampling of liquid steel
Material — steel
Damn.10
APPENDIX 1. (Changed edition, Rev. N 1, 2).
ANNEX 2 (mandatory). SCHEME OF SAMPLING FROM BILLETS, FORGINGS AND ROLLED PRODUCTS FOR CHEMICAL ANALYSIS
ANNEX 2
Mandatory
Damn.1
Damn.2
Damn.3
Damn.4
APPENDIX 3 (obligatory). SCHEME OF SAMPLING FROM BILLETS AND FINISHED STEEL FOR SPECTRAL ANALYSIS
APPENDIX 3
Mandatory
Damn.1
Damn.2
Damn.3
Damn.4
Damn.5
Damn.6
Damn.7
Damn.8
Damn.9
Damn.10
Damn.11
APPENDIX 4 (recommended). SELECTION AND PREPARATION OF SPECIMENS AND SAMPLES FOR TESTING FORGED STEEL
ANNEX 4
Recommended
Part 2. Samples for determination of chemical composition
ISO 377−2-89
1. Appointment
1.1. This standard specifies methods for obtaining samples for determining the chemical composition of the steel, except the definition of hydrogen content.
The samples are designed to test that (if there are no other agreements between the parties concerned) is carried out in accordance with the methods specified in the product standard, or, in his absence, in the standard to the test.
For comparison with the technical condition of selected sample with the average chemical composition.
Methods of determination of chemical composition are divided into two groups:
a) chemical methods, involving the introduction of a sample in a chemical reaction (see section 5);
b) physical methods for defining the constituent elements without a chemical reaction (see p. 6).
1.2. This standard applies to raw products, semi-finished products and forged steel products that are the subject of ISO 404−81, and does not apply to samples of products of melting or refining. In cases where product standards or standards on the testing set different terms, those different terms apply.
_______________
* With regard to this standard the concept of «raw food» includes not only metal bullion, and products: blooms, slabs and billets other profile.
2. Links
ISO 377−1-89 Selection and preparation of specimens and samples for testing of forged steel. Part 1. The samples and the samples for mechanical testing
ISO 404−81 Steel and steel billet. General technical delivery conditions
3. Terms
3.1. Sample product: a product (e.g. a leaf) selected from the party for procurement of samples.
3.2. Sample: a certain amount of solid material taken from the sample product as a sample for analysis (see p.3.3).
3.3. A sample for analysis: a certain amount of material taken from the sample or directly from the product, preserving the average chemical composition of the product.
The samples are divided into the following categories:
samples in the form of chips (see.5);
solid samples (see p.6.1);
extruded samples (see p.6.3);
melted samples (see p.6.4).
3.4. And selected weighted sample: part of a sample or the entire sample taken for analysis.
Note. Alternative methods of sample preparation shown in the drawing for information only.
4. The selection and preparation of samples
4.1. Locations of samples and their sizes
Samples can be selected only in the places established by the product standard.
In the absence of appropriate requirements in the product standard or specifications of the manufacturer samples for analysis should be selected from samples and specimens designed for mechanical tests (see section 5.1 ISO 377−1), or select directly from the product. In this case, the samples of round hire full and partial profile cut from one end of the workpiece in cross section.
Sample sizes should be sufficient to conduct, if necessary, re-testing.
4.2. Sample identification
The samples should bear identification markings in order to be able to install the product from which they are selected, and place selection.
4.3. Preparation of the sample surface
All coatings or contaminants (such as mill scale or grease) must be removed from the surface of the sample by any suitable method. If necessary, the surface should be degreased using the appropriate solution.
If the chemical composition of the surface of the product tends to change, the relevant part of the sample surface can be removed.
After these operations, you must protect the sample from contamination.
4.4. Storage of samples for analysis
To avoid contamination or any changes in the samples must be stored in dry containers made of chemically inert materials having a high abrasion resistance steel.
Containers should be provided with appropriate marking and, if necessary, sealed. Containers in which samples stored that are subject to arbitration examination shall be sealed by the manufacturer and the consignee or their representatives.
In the absence of special agreement, the storage containers assigned to the party responsible for sampling.
The numbers refer to relevant paragraphs in the text.
5. The selection and preparation of samples in chip form for determination of chemical composition by chemical analysis methods
5.1. Machining and cutting
All tools, machines and containers used for sample preparation must undergo pre-treatment to prevent any contamination of samples for analysis.
For sampling throughout the cross section of the product use planing, milling, turning or cutting.
If samples are not taken across the cross section, and in some places, usually used for drills or one of the following types of metal processing.
The use of lubricating-cooling substances is permitted only in exceptional cases. In this case, the chip should be cleaned with any solution, leaves no rain.
When machining the product is not allowed oxidation and overheating of chips. The inevitable emergence of tint chips as a result of heating during the processing of some types of manganese and austenitic steels must be minimized by proper selection of cutting tools and cutting speed.
In the result of the cutting is supposed to be small chips of such size that it is not necessary for me to shred in accordance with the requirements of section 5.2.1 during the preparation of samples for analysis.
The size of the chip should be such that the mass of each chip ranged from 2.5 to 25 kg.
For unalloyed and low alloyed steel wool should have a mass of about 10 mg, for high-alloyed steels is about 2.5 mg.
If tested carbon steel, the chips should be as solid and compact (about 100 mg) to prevent chipping and loss of graphite. To determine the oxygen content of the chips obtained by mechanical processing of metal, is not suitable.
5.2. Crushing and screening
5.2.1. Grinding
If the chips are received in accordance with clause 5.1, not suitable for testing, it is crushed by crusher pre-treated.
If grinding is not suitable, use one of the types of cut.
5.2.2. Screening
If obtaining the desired sample needs screening, all the chips are sieved through a sieve with holes with a diameter of 2.5 mm.
If necessary, wholemeal chip re-crushed and sieved again.
If the sample contains dust, i.e. chips, which passes through a sieve with holes with a diameter of 0.050 mm, the dust must be separated by sifting, and thus obtained two fractions weighing. In this case, the sample will consist of two parts proportional to these fractions.
To determine the carbon content, take a sample, sieved through a sieve with holes with a diameter of 2.5 mm.
To determine the nitrogen content of the sample is subjected to mechanical processing so that as much as possible of the individual particles of size less than 0.050 mm.
Screening should be carried out, observing all the necessary precautions to avoid contamination, change and loss of material.
5.3. The mass of sample for analysis
The sample mass should be sufficient to conduct, if necessary, re-analyses. The number obtained for the analysis of the material is determined by weighing. Sufficient consider a mass of about 100 g.
5.4. Storage of samples for analysis
Storage of samples is carried out in accordance with the requirements of section 4.4.
Permitted to store samples for analysis in the form of a solid mass and to cook the chips as needed.
6. Selection and training of solid, extruded or molded samples for the determination of chemical composition by using physical methods of analysis
(Emission spectrometry in the visible and ultraviolet regions of the spectrum, x-ray fluorescence, mass spectrometry, etc.).
Depending on the requirements of product standard or by agreement of interested parties for trials use:
a) solid sample;
b) extruded or melted sample.
Note. Not all steel grades can be extruded and melt.
For analysis take a small volume of sample. The volume of the test material selected in accordance with the method of analysis.
6.1. Solid sample
A solid pattern is produced by separating from the workpiece a part of the material that can be placed on a special table or mounted in the sample holder of the analytical instrument.
The separation of the sample is carried out by sawing, planing, cross cutting, of the cut or punching.
The sample surface is polished, milled or treated with emery paper to clean, needed to conduct the analysis. For surface treatment of the specimen before the determination of silicon by the method of x-ray fluorescence analysis or emission spectrometry in an abrasive material is used alumina. Before you can define the same methods of aluminum content the surface of the silicon sample was processed with an abrasive. When determining the carbon content by the method of emission spectral analysis for processing the sample surface using the abrasive material on the oxide basis.
In the absence of any indication in the product standard for the analysis of selected part of the sample corresponding to the cross section of the product, if the specimen is sufficiently thick.
6.2. Solid specimen with the thickness less 1.5 mm
While carrying out some physical methods of analysis between the solid sample and the electrode (emission spectrometry in the visible and ultraviolet regions of the spectrum or mass spectrometry) of an electric arc or spark, which leads to heating of the solid sample. The thinner the sample, the more local heating.
For solid samples with thickness less than 1.5 mm, it may be necessary to use a special technology to reduce local heating from arcing. For example, edges of a solid sample can be welded* to a small steel plate or layering one side of the sample tin, and the second to leave free.
_______________
* Applies the method of autogenous welding with tungsten electrode in inert gas.
The surface should then be processed as specified in clause 6.1.
6.3. Extruded sample
The preparation of the chips is carried out by the same methods and under the same conditions as for samples intended for analysis by chemical methods (see PP.5.1 and 5.2).
About 10 g of small chips of the correct form is placed inside a metal ring with an inner diameter of about 25 mm. This ring is placed on a solid steel base with a completely flat well-polished top surface. Press with a plunger which freely enters the ring with negligible friction, creates a compressive force equal to at least 1800 MPa*.
_______________
* 1 MPa =1 N/mm=10 bar.
Then the surface is pressed in one sample with ring handle, as specified in clause 6.1. Thereafter analyzing the sample by physical methods.
The quality of the surface of the test sample to a certain extent depends on the shape and size of the chip. You should not use too small chips that can pass the sieve with holes with a diameter of less than 0.80 mm.
The calibration curves of the analytical device drawing on the results of the analysis of extruded samples.
6.4. Remelted sample
Turnings, solid samples or small pieces of steel can be molded in inert gases in a special melting devices, such as high frequency or arc furnace, to give it form, convenient for carrying out spectral analysis.
It is important that any recorded quantitative chemical changes of the material being melted, and that they had no significant effect on test results.
Note. To minimize changes in the chemical composition of the remelted material in it is often added as a deoxidizer 0.05 g of zirconium, and analytical instrument graduate the results of tests of standard samples melted.
ANNEX 4. (Added, Rev. N 2).
