Method for determining strength characteristics and value of grain in metallic materials and alloys. RU patent 2505811.
 Assessment method of resistance of steel items against local corrosion / 2504772Samples are taken from items; specimens with polished surface are produced; surface of specimens is treated with solution of 3-10% ions of rhodanate during 3-5 hours at pH 8.0-9.0. Then, quantitative analysis of sections damaged and undamaged by corrosion is performed by means of computer functions of the programme for processing of pictures, and corrosion resistance of items is estimated as per fraction of damaged surface. |
 Control method of structural state of hardened low-carbon steels / 2498262First, a specimen of rectangular shape is made; a bevelled cut is made on the specimen at an angle of 15-25° from lower base to upper one, thus taking specimen length as the base. Then, surface of the bevelled cut of the specimen is ground and an austenisation mode is performed in oxidation atmosphere by etching gas. The specimen is cooled in water or in the air; then, a microslice or a series of microslices is prepared on surface of small base of the specimen, thus grinding the layers parallel to large base of the specimen. Depth of decoration zone is measured by etching gas on microslice by means of a microscope; then, the investigated surface of microslice is etched with alcohol solution of nitric acid till boundaries of austenitic grains are determined; determined boundaries of austenitic grains are studied; depth of selective determination zone of boundaries of austenitic grains is determined, and the defined etching picture is photographed. As per investigation results of microslice surface, structural state of the specimen is evaluated step by step: first, decoration zone of structure by oxidation with etching gas, then, selective etching zone of actual boundaries of austenite grains, and finally, zone of simultaneous detection of boundaries and intra-grain structure of the investigated steel; then, full depth of penetration of etching gas to the investigated material is determined by summing depths of decoration zone with etching gas and zone of selective detection of boundaries of austenite grains at etching of microslice and multiplication of the obtained value by cosine of inclination angle of bevelled cut to the large base. |
| Method of determination of gold and silver content in sulphide ores and products of their processing / 2494160 Proposed method comprises annealing of initial charge, selective leaching and analytical determination of noble metal content in produced solution. Charge annealing is performed in microwave frequency field without access of air at 550-600°C Annealed product is leached in steps by adding successive volumes of thiourea sulphide solution. Content of noble metal in obtained solutions is analytically defined to sum obtained values for determination of noble metal content in initial charge. |
| Method for quantitative determination of cerium in steels and alloys / 2491361 Method includes dissolution of a sample of analysed alloy and separation of cerium from the base of the alloy and macrocomponents. At the same time the base and macrocomponents are separated from cerium by serial deposition and extraction of the alloy base and macrocomponents of the alloy from the solution. Deposition is carried out with sodium diethyldithiocarbamate, extraction - with dithizone in chloroform. After separation of the organic phase, the cerium content is detected in water phase with the spectrometric method. |
 Device to collect gases in metal melts and method to measure gas concentration therein / 2478954Proposed device comprises gas collecting body, immersion end, gas feed line terminating nearby said immersion end, and gas discharge line. Note here that gas collecting body has face side located on immersion end, and side walls. Note here that, at least, part of gas collecting body has gastight layer. Besides, invention covers application of said device for measuring gas content in metal melt. |
 Lyosol based on nano- and microparticles for toxicology tests / 2473897Lyosol contains 0.5-1 wt % nano- and microparticles of metals and/or metal oxides, 0.6-0.9 wt % sodium chloride, 4.0-4.5 glucose monohydrate and distilled water. |
 Device for measuring emf when stretched ferromagnetic metal fibre breaks in localised pulsed superstrong magnetic field / 2456587Field is created by a magnetic explosion generator based on one circular winding of an exploding wire, through whose centre the ferromagnetic metal fibre is passed, said fibre being stretched by a force close to a breaking force in the absence of a magnetic field. The plane of the winding is strictly orthogonal to the stretched fibre which is protected from the exploding winding by a piece of glass tube. The ends of the stretched ferromagnetic metal fibre are electrically connected to a measuring device, for example, a resonance amplifier or an oscilloscope, which picks up damped electric oscillations arising when the fibre breaks. |
 Method of detecting breakage of ferromagnetic fibre in localised superstrong magnetic field / 2455639Method employs a magnetic explosion generator to generate a magnetic field based on a coil of explosive wire. A centrally-symmetrically loaded ferromagnetic fibre made from ferromagnetic material, e.g., a thin wire made from rare-earth metals or compounds thereof, which is stretched by the load applied to it, is placed inside the coil. |
 Method of determining noble metals / 2451280Method of determining noble metals involves drying a sample with grain size 1 mm to constant weight at temperature 105-110°C and using the dried sample for second and subsequent one-off determination of noble metals. An undried sample is used during the first one-off determination, wherein sample material is mixed with a charge mixture, the obtained mixture is molten and the amount of noble metals in the melt is determined. The sample is dried during the first determination and the weight ratio of moisture in the sample is determined. Content of noble metals in the sample is determined using the formula: where Cme is content of noble metals in the sample, g/t, Mme is mass of the noble metal detected in the melt, mg, m1 is the mass of the sample material used in the first determination, g, W is the weight ratio of moisture in the sample. |
 Investigation method of structure of tube steels / 2449055Invention refers to investigation of structure of high-strength steels. Method involves interaction of tube steel specimen with water solution of sulphosalts, further flushing and drying of specimen and detection of areas of bainite of rack morphology by means of optic microscope. At that, after application to specimen surface of water solution of sulphosalts, there removed is formed film, and bainitic areas are detected by means of polarised light of optic microscope; after that, obtained pictures of specimen are fixed and parameters of the detected bainitic areas of rack morphology are determined. |
| 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 / 2253112Contact 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 / 2261436Method 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 / 2265213Method 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 / 2267111Method 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 / 2272850The 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 / 2281975Proposed 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 / 2288289Proposed 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. |
FIELD: metallurgy.
SUBSTANCE: at least two workpieces of wedge shape are manufactured, and after they are heated to different temperatures, deformation of each workpiece is performed by means of a longitudinal rolling method starting from a narrow end, and cooling is performed at different cooling rates to provide formation of different strength characteristics and size of grain. Each workpiece is divided at least into two specimens; size grain is determined by metallographic investigations, mechanical characteristics of each specimen are determined by strength tests, and temperatures are determined at performance of deformation and cooling rate. A mathematical model is developed, in which results of experimental investigations and calculations of stress-and-strain state of tested workpieces are combined.
EFFECT: lower number of physical experimental investigations and higher quality of summary data.
6 dwg
The invention relates to the field of modeling of technological processes, in particular to the modelling methods of finite elements (FEM) analysis of hot plastic deformation of metal materials and alloys, in processes of treatment of metals by pressure (OMD). This method can be used both in research and in industry.
Known method for determining the strength characteristics and size of grain in metal materials and alloys, including manufacturing of billets, CE heating, deformation, cooling, determination of the resulting stress-strain state and distribution of the obtained grain size (see, e.g., DE 2005014221, IPC B21J 5/00 from 05.10.2006)
The disadvantage of this method is that it does not allow the samples with different microstructures, grain size to determine the result of simulation of hot plastic deformation of metal materials and alloys, the values of the strength characteristics such as strength, hardness, plasticity, and grain size in samples according to the degrees of their deformation and cooling modes, including initial temperature and the cooling rate.
In the basis of the invention is to obtain samples with different microstructures, grain size to determine the result of simulation of hot plastic deformation of metal materials and alloys, the values of the strength characteristics such as strength, hardness, plasticity, and grain size in samples according to the degrees of their deformation and cooling modes, including initial temperature and the cooling rate.
The problem is solved by the fact that the method of determination of strength characteristics and size of grain in metal materials and alloys, including manufacturing of the preform, heating, deformation, cooling, determination of the resulting stress-strain state and distribution of the obtained grain size, the stress-strain state of the tested billet, for experimental investigations are made at least two blanks wedge-shaped and after are heated to different temperatures produce deformation of each procurement method longitudinal rolling starting with the narrow end and cooling produced at different speeds of cooling to ensure the formation of various strength characteristics and size of grain each workpiece share not less than two sample, determine the research grain size, tensile tests mechanical characteristics of each sample, which depend on the nature of the sample material, the temperature during deformation and the cooling rate and develop a mathematical model, in which combines the results of experimental studies and calculations.
As for experimental investigations are made at least two blanks wedge-shaped and after are heated to different temperatures produce deformation of each procurement method longitudinal rolling starting with the narrow end and cooling produced at different speeds of cooling to ensure the formation of various strength characteristics and grain size, each workpiece share not less than two sample, determine the research grain size, tensile tests mechanical characteristics of each sample, which depend on the nature of the sample material, the temperature during deformation and the cooling rate and develop a mathematical model, in which combines the results of the experimental researches and calculations of stress-strain state of the tested blanks, provided to obtain samples with different microstructures, grain size to determine the result of simulation of hot plastic deformation of metal materials and alloys, the values of the strength characteristics such as strength, hardness, plasticity, and grain size in samples according to the degrees of their deformation and cooling modes, including initial temperature and the cooling rate.
1 shows a wedge procurement; figure 2 - scheme of wedge rolling billets, figure 3 - wedge procurement after the longitudinal rolling in figure 4 - the scheme of the cut designs from the deformed procurement; figure 5 - the results of tests on samples of the type leveling machine Instron; figure 6 - the results of the simulation wedge rolling billets, where (a) the strain distribution, b) the distribution of temperatures.
The claimed method of determination of strength characteristics and size of grain in metal materials and alloys is carried out as follows.
For experimental investigations are made at least two blanks wedge-shaped (1) of metal material or alloy. On the lateral surface of each wedge of the workpiece at regular intervals put a vertical incision in the subsequent distribution of the degree of deformation along the length of the workpiece after rolling. After heating of billets to different temperatures produce deformation of each procurement method longitudinal rolling starting with the smaller end, which is made under at an angle of? (figure 2). The greater the angle α, procurement L and according to its thickness N, the larger the degree of deformation can be sold in the course of one experiment. Cooling deformed blanks (figure 3) produce the different speeds of cooling to ensure the formation of various strength characteristics and grain size. Each deformed harvesting (figure 4) share not less than two sample and the leveling machine, for example Instron will automatically determine the values of the limits of fluidity and strength depending on the conditions (figure 5). These mechanical characteristics depend on the nature of the sample material, its stress-strain state, the temperature during the deformation and the cooling rate. research grain size.
By results of tests is based functional dependence:
D=D*Km*Kε*Kτ, where
D - settlement option, such as grain size, tensile strength and other;
D - estimated value of a parameter to the basic values of temperature deformation, deformation degree and speed of cooling;
Km, Kε, Kτ - correction factors, corrective basic amount D depending on the temperature, degree of deformation and the cooling rate.
Then perform finite element mathematical modeling of the process of rolling billets wedge-shaped, for example, in the program DeForm 3D. Simulation parameters - contact friction, the geometry of the zone of deformation, temperature-speed mode selected in such a way to get the model as close as possible to real deformed harvesting. The result of simulation is a numerical pattern of the distribution of stress - strain state of the sample volume (fig.6 and 6b).
At the final stage of creating a mathematical model that combines the results of experiments and calculations of stress-strain state of the tested billet, i.e. the results of the physical research, such as durability, hardness, plasticity, obtained depending on the degree of deformation and cooling conditions with the picture of the distribution of the stress-strain state obtained by methods of finite elements of mathematical modeling.
The method allows to reduce the number of physical experimental research through the use of wedge-shaped workpieces, does not require the manufacture of the special equipment and tools, low cost, and the quality of the final data has high accuracy and provides solution of the task.
Method of determination of strength characteristics and size of grain in metal materials and alloys, including manufacturing of billets, heating, deformation, cooling, determination of the resulting stress-strain state and distribution of the amount of the received grain, notable for experimental investigations are made at least two blanks wedge-shaped and after are heated to different temperatures produce deformation of each procurement method longitudinal rolling, starting with the narrow end and cooling produced at different speeds of cooling to ensure the formation of various strength characteristics and grain size, each workpiece share not less than two sample, determine the research grain size, tensile tests mechanical characteristics of each sample that depend from the nature of the sample material, the temperature during deformation and the cooling rate and develop a mathematical model, in which combines the results of the experimental researches and calculations of stress-strain state of the tested billet.