Method of determining parameters of metal structure |
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IPC classes for russian patent Method of determining parameters of metal structure (RU 2317539):
                                  
 Method of determining real contents of components in samples / 2316763
Data required for reliable determination of sought contents are suggested to be obtained by way of reproducing attested contents of component in a set of auxiliary samples covering, by attested characteristics, content in a sample being examined and correcting dependencies between estimation of systematic error in analytic result and measured content be performing inter-laboratory experiment using standard samples.
 Overcooled austenite stability determination method / 2312904
Method is designed for determining influence upon stability of austenite stresses applied to sample, selected modes of hot and warm plastic deformation and cooling rate of articles. Method comprises steps of heating sample of low- and mean-carbon steel till austenite forming temperature; applying to sample load with predetermined sign and value; cooling loaded sample; measuring hardness along length of sample on two ground diametrically opposite surfaces; plotting and analyzing hardness distribution curve; according to changed positions of hardness distribution curves evaluating influence of stress-deformed state upon destruction of overcooled austenite.
 Method for evaluating practical conditions for using orderly alloy in radiation environments (variants) / 2293308
Method for estimating practical conditions for usage of orderly alloy in radiation environments includes stages: receipt of irradiated state diagram, which reflects connection of far order power to variable R of irradiated state, connected to speed of damage and irradiation temperature, on basis of estimation formula, related to influence of radiation on far order power of orderly alloy, positioned in radiation environments, during usage as parameters of first threshold value, at which far order power begins to decrease substantially during irradiation, of second threshold value, at which far order power practically reaches balance after decrease, and far order power in balanced state, computation of variable R of irradiated state under conditions of irradiation, at which alloy subject to estimation will be used, and finding of value S of far order power, determining of first threshold value, second threshold value and far order power in balanced state for one and the same value R.
 Method of concentrating and determining chromium and manganese ions in biological substrates / 2292545
Method comprises adding test sample to silica gel preliminarily treated with cetylpyridinium chloride and then with phenylfluorene dissolved in water-ethanol medium. Sample is treated at pH 4-5 in determination of chromium and at pH 7-8 in determination of manganese. In order to calculate content of ions, diffuse reflection values are measured on spectrophotometer at wavelengths 530 and 590 nm, respectively for chromium and manganese.
 Method of quantitative determination of content of lithium in alloy / 2288289
Proposed method includes determination of initial mass of alloy specimen, heating the alloy specimen under test till separation of free lithium; mass of alloy specimen is determined in inert gas atmosphere; alloy specimen is heated to temperature not below sublimation temperature of pure lithium in vacuum at residual pressure not exceeding 1·10-6 atm; degree of rarefaction in closed space where heating is carried out is checked continuously; abrupt change in angle of inclination of branch of graph of change of specimen mass versus time of extraction of free lithium is indicative of complete distillation of free lithium; quantitative determination of content of free lithium is performed taking into account difference in mass of initial specimen of alloy and mass of specimen recorded at moment of attaining complete extraction of free lithium; specimen of alloy is heated in crucible made from inert refractory material; specimen is loaded into evaporating tube made from inert metal and placed in cavity of evaporating-condensing unit of distillation plant; its inner walls are made from quartz glass. Proposed method may be used for determination of free lithium contained in alloy in chemically unbound state.
Method of assay determination of content of gold in ores and in products of their processing / 2288288
Proposed method includes melting of starting material with lead oxide, soda, borax and flour for obtaining lead alloy (crude lead), its cupellation till gold-silver regulus, dissolving of silver in diluted nitric acid and determination of amount of gold by weighing or by any other instrumental method. Melting process is carried out in metal crucibles at temperature of 600-800°C for 10-30 minutes; charge per 10 g of sample contains the following components: 20-50 g of sodium or potassium hydroxide; 2-20 g of borax; 1-10 g of soda; 15-30 g of litharge and 1-3 g of flour. Method is recommended for assay of samples having mass of 10-100 g.
Method of determination of content of palladium and platinum in ores / 2283356
Proposed method includes decomposition of ore by hydrofluoric and nitric acids followed by further decomposition by aqua regia, boiling-off to moist salts, dissolving of them in hydrochloric acid and extraction. Determination of content of palladium is carried out in organic phase thus obtained and that of platinum is carried out in hydrochloric acid phase. Extractants used for such determination are s-alkylisothiouronium halides and alcohols of C5-C8 fractions, as well as kerosene, benzene, toluene and xylols used as diluents. Used as s-alkylisothiouronium halides are chlorides, bromides and iodides from C7 to C14 and their fractions.
 Method of determination of cause of low impact viscosity of low-carbon steels / 2281975
Proposed method consists in finding-out dependence of grain size of microstructure and presence of ferrite net, as wells as marks on bearing faces of tested specimens for products of the same type made from steel of definite quality during analysis of causes of low impact viscosity recommended standards are established for these parameters and dependences thus found are compared with the data of specimens of low (below standard norm) impact viscosity and these data are estimated for compliance with the recommended standards. Dependences thus found are used repeatedly and constantly.
 Method of a quality control over the test crucible melting / 2272850
The invention is pertaining to nonferrous metallurgy, in particular, to the methods of detection of the noble metals in the mineral raw materials. The technical result of the invention is an increased trustworthiness to the results of the testing crucible melt analysis. The method is conducted in the following way. From the material of the laboratory test sample take out the analytical part of the filler, mix it with the calculated amount of the charge and the mixture is smelt according to the standard method. During the smelt visually control the height of the boiling layer of the melt slag and lead. On completion of the smelt measure the mass of the slag and lead and calculate an admissible height of the boiling layer of the melt according to the following formula:0,9·Hm≥Hc≥[1,9/tg2α/2·(Mш/ρш+Mc/ρc)]1/3, whereHcr - depth of the crucible in meters(m);Hsl - the height of the boiling gas-slag layer, m; α - an angle at the apex of the cone of the inner surface of the crucible, in degrees;Msl, Mla - masses of the slag and mass of the lead alloy accordingly, kg;ρsl, ρla - density of the slag and density of the lead accordingly, kg/m3. If the visual estimation of the height of the boiling layer of the melt exceeds the limits of admissible values, them one may draw a conclusion about the low quality of the testing smelt, make corrections in the composition of the charge and repeat the test analysis.
 Method of preparing samples for analysis / 2267111
Method comprises sampling initial material, producing and analyzing group samples before assessing representative mass of analytical samples, estimating representative mass of analytical samples, and calculating the value of the coefficient that characterizes the type of gold-bearing material from the formula proposed.
Material for production of assay stone / 2248336
Assay stone is made from oxide ceramic comprising BeO-TiO2. Material affords the ability to obtain assay stone of regular geometric form with surface, electrical and mechanical properties meeting the requirement for material used in assaying control. Claimed material in useful in standard determination followed by electrochemical recovery of precision metals from solution after assaying control.
 Mode of testing railway rails on contact weariness / 2253112
Contact weariness is induced by high-frequency dynamic components of interaction of wheels and rails, which become apparent at moving at high speed. The mode of testing railway rails on contact weariness is in that tested samples of rail steel are rolled by pinch rolls in longitudinal direction until appearance on the surface of the sample of dents and also deep indents. As samples test rails are used. The diameter of a pinch roll is chosen under condition of equality of reduction ratio of linear size of the site of contact of the pinch roll with the rail along the axis of the last in comparison with corresponding size responsible to conditions of exploitation and speed reduction ratio of rolling motion of the pinch roll along exploited rail.
 Method of measuring duration of serviceability of metals / 2261436
Method can be used for estimation of deformation-strength properties due to applying load as well as for determining damages by means of X-ray diffraction analysis. Values of structural-sensitive parameter of crystal lattice of tested material are determined by X-ray diffraction analysis in initial and post-deformation states. Deformation-strength characteristics of metal are determined by calculation from changes in structural-sensitive parameter. Serviceability is judged by comparing really achieved characteristics with admissible ones. Width of X-ray line β is used as structural-sensitive parameters. Strength of deformation P, deformation Δl provided by the deformation and corresponding values of structural-sensitive parameter β are registered during testing. Dependence of true stresses S and structural-sensitive parameter β on degree of relative residual deformation δ are calculated on the basis of P and Δl. Destruction diagram (S-δ½) and linearized diagram (β½-δ½) are built to show inflection points. Deformation-strength characteristics SD and δD corresponding to inflection point at destruction diagram (destruction point D) is taken as criterion of admissible surface strength which provides maximal serviceability of metal. Factor of merit η and factor of destruction Δ can be also taken as criteria of serviceability of metal.
 Method for determining hardness limit of austenite class steel / 2265213
Method includes subjecting samples of steel to preliminary plastic deformation and on basis of wear test results of pre-deformed samples, graph of change of hardness limit of σ-1 samples is built dependent on their level of pre-deformation. Weighed samples are made with same deformation level and value of magnetic tear force Pmag is determined for each weighed sample. Graph of change of magnetic tear force Pmag is built for samples on basis of their pre-deformation level, graph with adjusting curve in coordinates Pmag - σ-1, setting a connection between Pmag and σ-1 dependent on level of pre-deformation. Hardness limit of σ-1 samples is determined by adjusting curve in coordinates Pmag - σ-1.
Method of preparing samples for analysis / 2267111
Method comprises sampling initial material, producing and analyzing group samples before assessing representative mass of analytical samples, estimating representative mass of analytical samples, and calculating the value of the coefficient that characterizes the type of gold-bearing material from the formula proposed.
Method of a quality control over the test crucible melting / 2272850
The invention is pertaining to nonferrous metallurgy, in particular, to the methods of detection of the noble metals in the mineral raw materials. The technical result of the invention is an increased trustworthiness to the results of the testing crucible melt analysis. The method is conducted in the following way. From the material of the laboratory test sample take out the analytical part of the filler, mix it with the calculated amount of the charge and the mixture is smelt according to the standard method. During the smelt visually control the height of the boiling layer of the melt slag and lead. On completion of the smelt measure the mass of the slag and lead and calculate an admissible height of the boiling layer of the melt according to the following formula:0,9·Hm≥Hc≥[1,9/tg2α/2·(Mш/ρш+Mc/ρc)]1/3, whereHcr - depth of the crucible in meters(m);Hsl - the height of the boiling gas-slag layer, m; α - an angle at the apex of the cone of the inner surface of the crucible, in degrees;Msl, Mla - masses of the slag and mass of the lead alloy accordingly, kg;ρsl, ρla - density of the slag and density of the lead accordingly, kg/m3. If the visual estimation of the height of the boiling layer of the melt exceeds the limits of admissible values, them one may draw a conclusion about the low quality of the testing smelt, make corrections in the composition of the charge and repeat the test analysis.
Method of determination of cause of low impact viscosity of low-carbon steels / 2281975
Proposed method consists in finding-out dependence of grain size of microstructure and presence of ferrite net, as wells as marks on bearing faces of tested specimens for products of the same type made from steel of definite quality during analysis of causes of low impact viscosity recommended standards are established for these parameters and dependences thus found are compared with the data of specimens of low (below standard norm) impact viscosity and these data are estimated for compliance with the recommended standards. Dependences thus found are used repeatedly and constantly.
Method of determination of content of palladium and platinum in ores / 2283356
Proposed method includes decomposition of ore by hydrofluoric and nitric acids followed by further decomposition by aqua regia, boiling-off to moist salts, dissolving of them in hydrochloric acid and extraction. Determination of content of palladium is carried out in organic phase thus obtained and that of platinum is carried out in hydrochloric acid phase. Extractants used for such determination are s-alkylisothiouronium halides and alcohols of C5-C8 fractions, as well as kerosene, benzene, toluene and xylols used as diluents. Used as s-alkylisothiouronium halides are chlorides, bromides and iodides from C7 to C14 and their fractions.
Method of assay determination of content of gold in ores and in products of their processing / 2288288
Proposed method includes melting of starting material with lead oxide, soda, borax and flour for obtaining lead alloy (crude lead), its cupellation till gold-silver regulus, dissolving of silver in diluted nitric acid and determination of amount of gold by weighing or by any other instrumental method. Melting process is carried out in metal crucibles at temperature of 600-800°C for 10-30 minutes; charge per 10 g of sample contains the following components: 20-50 g of sodium or potassium hydroxide; 2-20 g of borax; 1-10 g of soda; 15-30 g of litharge and 1-3 g of flour. Method is recommended for assay of samples having mass of 10-100 g.
Method of quantitative determination of content of lithium in alloy / 2288289
Proposed method includes determination of initial mass of alloy specimen, heating the alloy specimen under test till separation of free lithium; mass of alloy specimen is determined in inert gas atmosphere; alloy specimen is heated to temperature not below sublimation temperature of pure lithium in vacuum at residual pressure not exceeding 1·10-6 atm; degree of rarefaction in closed space where heating is carried out is checked continuously; abrupt change in angle of inclination of branch of graph of change of specimen mass versus time of extraction of free lithium is indicative of complete distillation of free lithium; quantitative determination of content of free lithium is performed taking into account difference in mass of initial specimen of alloy and mass of specimen recorded at moment of attaining complete extraction of free lithium; specimen of alloy is heated in crucible made from inert refractory material; specimen is loaded into evaporating tube made from inert metal and placed in cavity of evaporating-condensing unit of distillation plant; its inner walls are made from quartz glass. Proposed method may be used for determination of free lithium contained in alloy in chemically unbound state.
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FIELD: investigating or analyzing of materials. SUBSTANCE: method comprises choosing a region on the visible image of grain structure of metal, applying a set of parallel secants that are arranged at the same distance one from the other and a set of secants perpendicular to then on the region, measuring the lengths of the chords formed by intersecting of secants of both of the sets with the boundaries of the grains, and performing reconstruction of the structure. EFFECT: enhanced precision. 5 dwg, 6 tbl, 1 ex
The invention relates to the field metallographic studies and analysis of materials, in particular to methods for determining the main parameters of the metal structure. It is known that almost all physical and mechanical properties of metals and alloys are structure-sensitive, i.e. properties such as strength, ductility, impact strength, heat resistance, corrosion resistance, thermal conductivity, magnetic permeability, and many others, depend directly on the size of structural components (grains) and their degree of uniformity throughout the volume of the product. Getting those or other properties in the finished products provided by the combination of deformation and heat treatment regimes are developed on the basis of studying the structure of a flat slice samples cut from the product at some stage of its manufacture. Currently, the determination of the number of grains per unit area and the average grain size of carry out on the flat cut (cut) and it gives a very approximate idea of the structure of the metal in the volume that does not allow you to confidently judge the correctness of the selection of appropriate modes of deformation and heat treatment. This situation leads to marriage in the production of articles is very responsible destination. For example, in the manufacture of pipes-about the next fuel elements of nuclear power plants of expensive Nickel-chromium alloys marriage on the grain size and mechanical properties reaches 3-5%. The same situation is observed in the production of boiler tubes of stainless steel 12X18H10T, requirements for which are present on the grain size and raznozernistoy. Requirements for grain size and raznozernistoy apply to products used in electrical engineering (molybdenum filament), aircraft industry, medicine and other industries. There is a method of determining the main parameters of the metal structure, including manufacturing of cut, obtaining a visible image grain patterns on flat slice, photography section of one of the grains measured on the photographic picture of the geometry and distribution of the derived values in fractions by size. When using this method to select measurement intervals using a predetermined interval table conversion, and the dimensions of the measurement intervals governed by the methods of calculating the values of distribution parameters. The actual dimension of the flat sections produce visually by moving the cut micrometer screw table of the microscope in the direction perpendicular to the line of the eyepiece. When you do this: first carry out a preliminary view of the rack, install the largest diameter or the largest area of the observed cross sections, and then octanal who provide dimensional intervals diameters; - to distribute sections of the grain size pre-set the number of size groups, for example, in the range from 7 to 12; - magnification selected so that the diameter of the largest cross section was equal to the whole number of divisions ocular ruler of the microscope in the range from 7 to 12. (Saulteau. Stereometric metallography. - M., 1976. - P.222-228) This method allows you to define only the distribution of the cross sections of the grain size to calculate the number of grains per unit area and the average diameter of the grain. This process is characterized by low accuracy due to errors that occur in the complex process of a method for measuring objects flat face. There is also known a method of determining the main parameters of the metal structure, including manufacturing of cut, obtaining visible images of the grain structure of the metal structure and the selection on the image structure representative of its region, which is applied to a group of parallel equally-spaced hooking subsequent measurement values of the chords formed by the intersection of a representative area of the image group intercept, and the obtained set of measurements to produce a reconstruction of the structure, and then judge the values of its parameters. At the same time as representative of the area photographed maximum széchenyi is one of the grains, and after reconstruction is judged on the size distribution of the flat sections of the grain and its average diameter (A.S. No. 1397832, G01N 33/20, 88). When using this method the accuracy of the reconstruction of the structure is low, because it gives the possibility to define parameters only monodisperse system, consisting of grains of the same size as the researched. The actual patterns are polydisperse system. In addition, this method provides receiving only such basic parameters of the metal structure, as the distribution of sizes of flat sections grains. So its technological capabilities and its application in the development of heat treatment of the metal is extremely limited. The basis of the invention is the task of improvement of the method of determining the main parameters of the metal structure by changing the treatment conditions of the visible images of the grain structure of the metal structure and methods for its reconstruction, which results in improving the accuracy of the found values of the main parameters of the structure, while ensuring the expansion of technological capabilities of the method. The problem is solved by the fact that in the method of determining the main parameters of the metal structure to receive the visible image of the grain structure of the metal structure from scratch, choose n is the image patterns of a representative region, on which is applied to a group of parallel equally-spaced hooking subsequent measurement values of the chord formed by the intersections of grain boundaries of a representative area of the image group intercept, on the received set of measurements to produce a reconstruction of the structure, according to the invention as a representative area of the image grain patterns choose the aggregate not less than 3 adjacent to each other grains, on which is applied as a group of parallel equally-spaced hooking and perpendicular thereto is a second identical group, hooking, measuring the length of the chord formed from the intersection of the clipping both groups boundaries of the selected aggregate grains, find the values of the distribution of the measured chord at predetermined intervals, and produce a reconstruction of the flat sections of the grain by solving the system of linear equations of the form:
where: n is the number of measurement intervals; k is the sequence number of any of 1 to n of the measurement interval; Pk(l) - distribution of chords on a flat slice in any k-th measurement interval; Pk(δ) - found during the reconstruction of the distribution of flat sections of grains in any k-th measurement interval; δk- the diameter of the grain on the flat slice corresponding to the middle of any k-interval measurements, and the reconstruction of the volumetric structure of the metal is carried out by the solution of an analogous system of linear equations of the form:
where: n is the number of measurement intervals; Pk(δ) - distribution of flat sections of grains in any k-th measurement interval; Pk(D) is found during the reconstruction of the distribution of the diameters of the grains in any k-th measurement interval volume; Dk- the diameter of the grain in the volume corresponding to the middle of any k-interval measurements, then find the distribution of grains in the volume and number of characteristics that define the basic parameters of the structures in the volume. As can be: the size of each grain representative of the region; the number of grains and the distribution of their sizes in the volume of metal; average grain size; - the standard deviation of the average size; the coefficient of variation characterizing the degree of homogeneity of the structure. The proposed method differs from the method prototype that representative region includes the set of grains, i.e. polydisperse system, which is applied as a group of parallel equally-spaced hooking and perpendicular thereto is a second identical group, hooking, measuring all lengths of chords, formed is the result of crossing borders representative region, and solve the system of linear equations proposed species, and at first produce a reconstruction of the flat sections of the grains, and then produce a reconstruction of the volume structure, and solving the same system of linear equations, find the distribution of grains in the volume and characteristics of the main parameters of the bulk metal structure. The technical result of the proposed method in comparison with the prototype is to improve the accuracy of the found values of the main parameters of the structure, while ensuring the expansion of technological capabilities of the method. This is because the processing of the received visible image the grain structure of the metal structure is produced in two stages by the present formula, can not limit the number of measurement intervals and sections with subsequent high-precision measurement of the values of chords and, thereby, to increase the accuracy of the reconstruction and the number of measured parameters. As a representative region choose the polydisperse system, consisting of at least three grains, and not monodisperse, as in the prototype - one grain with a maximum cross-section, which also improves accuracy while ensuring receipt of any structure parameters, not two, as in the prototype - size distribution and the average diameter of the grain. Specified in conjunction with the use of the principle of ravnomernost provisions of hooking elements on dissected objects in the plane and in space, as well as the application conditions of superposition (the Soviet encyclopedic dictionary. - M.: Soviet encyclopedia, 1982. - 1284 C.) for a polydisperse system of interest has led to the same kind of systems of linear equations, allowing to reconstruct the structure as the transition from the line to the plane, and the transition from the plane to the volume, thereby improving the accuracy of the method and expanding its technological capabilities.The figure 1 shows a photograph of a typical grain of the microstructure of a single-phase austenitic steels marked with a bold line representative area of the treated microstructure. The figure 2 shows a diagram of a selected representative area after recognition and editing during processing. The figure 3 presents the distribution of chords flat face P(l), obtained after processing schematic image of a representative region, shown in figure 2, where l is the chord length in microns. The figure 4 presents the distribution of the diameters of the grains flat face P(δ)obtained in the first stage of reconstruction, where δ grain diameter in microns. The figure 5 presents the distribution is of yamacraw grains in the volume of P(D), the resulting second stage of reconstruction, where D is the diameter of the grain volume in mcm. The proposed method is as follows. The samples are polished, the surface is etched receive using metallographic microscope visible grain structure of the metal sample and photograph it. The processing of the received visible image the grain structure of the metal structure and the reconstruction of the structure is carried out, for example, using the computer, and as a representative region displayed on the display screen of the computer image grain patterns choose a set of at least three adjacent grains, which is applied as a group of parallel equally-spaced hooking and perpendicular thereto is a second identical group, hooking, measuring the length of the chord formed from the intersection of the clipping both groups boundaries of the selected aggregate grains, then find the value distribution of the measured chord at predetermined intervals and produce a reconstruction of the flat sections of the grain by solving the system of linear equations of the form:
where: n is the number of measurement intervals; k is the sequence number of any of 1 to n of the measurement interval; Pk(l) - distribution of chords on a flat slice in any k-th interval metering the deposits; Pk(δ) - found during the reconstruction of the distribution of flat sections of grains in any k-th measurement interval; δk- the diameter of the grain on the flat slice corresponding to the middle of any k-interval measurements. Then carry out the reconstruction of the volumetric structure of the metal by the solution of an analogous system of linear equations of the form:
where: n is the number of measurement intervals; Pk(δ) - distribution of flat sections of grains in any k-th measurement interval; Pk(D) is found during the reconstruction of the distribution of the diameters of the grains in any k-th measurement interval volume; Dk- the diameter of the grain in the volume corresponding to the middle of any k-interval measurements. Then find the distribution of grains in the volume and the corresponding numerical characteristics that define the basic parameters of the structures in the volume. A specific example. Of pipe sizes 16×1 mm (steel 08KH18N10T) made the cut, which is to reveal the microstructure protravel in nitric acid and using a metallographic microscope MIM received image patterns on a flat cut. Then, selecting a representative area (figure 1), have entered this image into the computer, put it on this image two groups of equally spaced parallel from each other is and intercept in two mutually perpendicular directions, measured length all the chords and calculated their distribution by size groups, the number of which is assumed to be Data obtained measurements are shown in table 1.
Taking δ1=l1=15...δn=ln=75, prepare a system of n equations. In our case, n=8; k=1, 2, 3...8. Then to find the distribution of the diameters of the grains on the flat is cut (δ ) make the following system of equations:
Solving the system of equations, for example, using a computer, produce a reconstruction of the flat sections of the grain and get the distribution of the diameters of the grains on a flat slice, which is the source for the subsequent reconstruction of the distribution of the diameters of the grains in the volume. The results of the reconstruction are shown in table 2.
Taking D1=δ1=5 μm; D2=δ2=15 ám... Dn=δn=75 μm; n=8; k=1, 2, 3...8, make the system of equations necessary for reconstruction of volumetric metal structure:
Solving this system of equations, for example, using a computer, we obtain the distribution of the diameters of the grains in the volume and produce a calculation of all parameters of the structure on the line (chords l), on the plane (diameter flat face δ) and in volume (diameter D). All the data are in tables 3, 4, 5.
The accuracy of the proposed method of determination of structure parameters in comparison with the way the m prototype has increased in tens times only due to the measurement of many grains instead of one, as in the prototype. In addition, the increase in representative areas also improves the accuracy of statistical processing and provides more opportunities for other parameters grain patterns. On the basis of these data the following parameters of the metal structure, are shown in table 6.
Substitution of the values of the diameters of the flat sections is greater than or less than the values obtained from the mathematical expressions, the stated equations reconstruction, leads to an increase in errors in the determination of the parameters of the metal structure. Using the prototype method on the same flat cut (cut) resulted in average grain volume diameter 43,7 mm, which according to GOST 5639 corresponds to the number 6 and represents a clear error of the method based on using a single maximum grain in the form of a representative area. Thus, the application of the proposed method in comparison with the prototype allows to increase accuracy while expanding the technological capabilities of the method definition, which increases the range of its application when using the re regimes of thermal treatment of the product. The method of determining the main parameters of the metal structure, which receive the visible image of the grain structure of the metal structure from scratch, choose the image patterns of a representative area that put a group of parallel equally-spaced hooking subsequent measurement values of the chords formed by the intersection of the boundaries of a representative area of the image group intercept, and the obtained set of measurements to produce a reconstruction of the structure, characterized in that as a representative area of the image grain patterns choose a set of at least 3 adjacent to each other grains, which is applied to a group of parallel equally-spaced hooking and perpendicular thereto, a second identical group intercept, measure the length of the chord formed from the intersection of the clipping both groups boundaries of the selected aggregate grains, find the values of the distribution of the measured chord at predetermined intervals and produce a reconstruction of the flat sections of the grain by solving a system of linear equations of the form
where n is the number of measurement intervals; k is the sequence number of any of 1 to n of the measurement interval; Pk(l) - distribution of chords on a flat slice in any k-the measurement interval; Pk (δ) - found during the reconstruction of the distribution of the diameters of the flat sections of the grains in any k-th measurement interval; δk- the diameter of the grain on the flat slice corresponding to the middle of any of the k-th measurement interval, and the reconstruction of the volumetric structure of the metal is carried out by the solution of an analogous system of linear equations of the form
where n is the number of measurement intervals; Pk(δ) - diameter distribution of flat sections of grains in any k-th measurement interval; Pk(D) is found during the reconstruction of the distribution of the diameters of the grains in any k-th measurement interval volume; Dk- the diameter of the grain in the volume corresponding to the middle of any of the k-th measurement interval, then find the distribution of the diameters of the grains in the volume and the corresponding numerical characteristics that define the basic parameters of the structures in the volume.
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