Overcooled austenite stability determination method |
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IPC classes for russian patent Overcooled austenite stability determination method (RU 2312904):
      
 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.
 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 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.
 High-strength steel sheet with molten zinc coat and method of manufacture of such sheet / 2312162
Proposed zinc-coated steel sheet has galvanic coat layer made from Zn containing aluminum at concentration of from 0.01 to 1 weight-%, the remainder being Zn and unavoidable admixtures; it contains oxide particles within 2 mcm from interface of steel sheet whose average diameter ranges from 0.001 to 1 mcm; oxides are of one type selected from Al oxide, Si oxide, Mn oxide or complex oxide containing at least two elements from Al, Si and Mn. Heating temperature at re-crystallization annealing stage in reduction furnace ranges from 650°C to 900°C; steel sheet is passed through atmosphere where ratio of partial pressure of water steam PH2O and partial pressure of hydrogen PH2 satisfies the following inequality:
 Circular inductor / 2312154
Proposed inductor has heat-conducting external ring made from tube and used for admitting the heat-exchange medium due to concentration of electromagnetic field of inductor in obtaining narrow zone of heating; inductor is also provided with internal electric-conducting and heat-conducting ring having solid cross section and area of surface corresponding to preset density of high-frequency current. These rings are interconnected through heat-conducting adapter members in form of sectors. Internal ring is electrically connected with current-supply buses. External ring may be made from conducting material and may be electrically connected in parallel with internal ring. In this case, adapter members may be also made from conducting material. Proposed inductor is used for growing the crystals by crucible-free zone-type melting whose diameter exceeds 25 mm at complete zone of melting with diameter of inductor exceeding that of crystal.
 Method of heating ingots and blanks made from titanium-based alloy for piercing in skew rolling mills / 2312153
For smooth heating of ingots and blanks and for production of quality sleeves, proposed method excludes drilling central hole 100±5.0 mm in diameter in ingots and blanks; ingots and blanks are placed in muffles on clean hearth of continuous heating furnace; they are placed on hearth in one row at interval of 10-15 minutes and are heated in three zone-type continuous heating furnaces to temperature of 1155-1180°C , after which they are kept in pit for 6.0-19.0 minutes and are pierced for forming sleeves in skew rolling mill; they are heated at rate of (3.0-4.0) °C/min and are manipulated through angle of α=180±30° ; manipulating to pit is performed from the third port of first zone of furnace; ingots and blanks are kept in pit for 5.0-8.0 min. In case rolling mill is stopped for 30 min and there is no place in furnace, to and fro manipulating is performed in 15.00-20.0 min through angle of α=180±30° and in case rolling mill is stopped for more than 30 min, articles are unloaded from furnace in 15.0-20.0 min and are manipulated along furnace through angle of 180±30°.
 Carbon steel sheets production method / 2309990
Method shortening time period of recrystallization annealing and simultaneously providing high mechanical properties of steel sheets comprises steps of cold rolling of strips; subjecting pile of steel coils in hood furnace to recrystallizaton annealing at heating till annealing temperature 690 - 710°C and cooling them; in temperature range 190 - 210°C before annealing temperature heating coils at rate no more than 72°C/h; cooling coils at first till temperature 650 -680°C for time period 7 - 15 h after termination of which completing cooling stage at arbitrary rate. Cold rolling is performed at total percentage reduction 55 -80% while used carbon steel contains next ingredients, mass%: carbon, 0.02 - 0.12; manganese, 0.08 - 0,55; aluminum, 0.01 - 0.10; silicon, less than 0.05; phosphorus, less than 0.03; sulfur, less than 0.03; nitrogen, less than 0.012; iron, the balance.
 Articles strengthening method / 2309988
In order to improve fatigue strength of article subjecting it (before surface hardening) to induction heating of non-uniformly heated zones (mutually joined zones of article) and then soaking article. Induction heating of non-uniformly heated zones may be realized simultaneously or continuously- successively. Induction heating of non-uniformly heated zones is realized, preferably in temperature range Aci - AC3.
 Method for making working organs of cultivators / 2309987
In order to improve wear resistance of working organs of tilling cultivators made of steel 60C2A, after imparting desired shape to working organ subjecting it to preliminary heat treatment at hardness 40 - 48 HRC; then surfacing stripes onto working surface of working organ by means of electrode and performing chemical-and-heat treatment by means of nitrogen for providing hardness of working surface 55 - 62 HRC. Invention provides increased by 1.5 times wear resistance of working surface of working organ.
Tool made of high-speed steel / 2307172
In order to increase useful life period of tool of high speed steel P6M5 containing α-phase - martensite α-Fe alloyed with chrome, tungsten and molybdenum; γ-phase - austenite alloyed with chrome, tungsten and molybdenum, carbide Fe6Mo3W3C2 and vanadium carbide VC, concentration of austenite is no more than 2.0 ± 0.6 mass%, concentration of martensite is no less than 85.2 ± 4.0 mass%; concentration of Fe6Mo3W3C2 - 8.9 ± 0.5 mass%; concentration of VC - 2.8 ± 0.5 mass%.
Tool made of high-speed steel / 2307007
Tool made of high-speed steel P18 may be in the form of cutter, milling cutter, drill, screw tap and so on. High-speed steel of tool contains α-phase - martensite α-Fe alloyed with chrome and tungsten; γ-phase - austenite alloyed with chrome and tungsten; and carbide Fe3W3C. Austenite concentration is no more than 4.4 ± 0.5 mass%; martensite concentration is no less than 84.3 ± 4.0 mass %; concentration of Fe3W3C is equal to 11.3 ± 0.6 mass%.
Tool made of steel / 2306207
Tool is made of steel containing as main structural component ferrite a-Fe alloyed with chrome and molybdenum. Mean size of a-Fe blocks is no more than 35 nm; micro-deformations of crystal lattice of a-Fe are no more than 4.3 x 10-3. Invention provides increased strength and lowered embrittlement of ferrite a-Fe.
Tool made of high-speed steel / 2306206
Tool is made of high speed steel P6M5 containing as main strutural component ferrite a-Fe alloyed with chrome, tungsten and molybdenum. Mean size of a-Fe blocks is no more than 47 nm; micro-deformations of crystal lattice of a-Fe are no more than 5.2 x10-3. Invention provides improved strength and lowered embrittlement of ferrite a-Fe.
 Installation used for rolled metal cooling / 2244022
The invention presents an installation for rolled metal cooling and is dealt with metal rolling, in particular with cooling of rolled metal. The installation for rolled metal cooling contains a body with an inlet branch-pipe and two rows of outlet branch-pipes displaced from each other by a half step. Value of a step of the outlet branch pipes in each row does not exceed four internal diameters of the branch-pipes. Across the body opposite to an entry of the inlet branch-pipe a dissector is installed. Along the body opposite to the outlet branch-pipes there are two entire central plates and two fragmentary lateral plates forming two longitudinal funnel-shaped cavities, turned by their narrow parts to each row of outlet branch-pipes. Fragmentariness of the lateral plates is created at the expense at least of one cutout in the base of each plate, at the longitudinal butts of which there are two perpendicularly fixed damping plates facing inside the funnel-shaped cavities. The invention allows to increase evenness, flexibility and efficiency of the rolling metal cooling process and ensures reliable operation of the installation.
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FIELD: metallurgy, namely methods for determining influence of outer actions upon stability of overcooled austenite of low- and mean-carbon steels. SUBSTANCE: 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. EFFECT: enhanced accuracy of determining factors influencing upon stability of austenite. 3 dwg
The invention relates to metallurgy, and in particular to methods of determining the impact of external influences on the stability of the supercooled austenite (UPA) small - and medium-carbon steels, in particular the magnitude and sign of the applied stresses, and can be used for mode selection of hot and warm plastic deformation and the rate of subsequent cooling products. UPA is the most important property of the steel, because it determines the mechanisms of disintegration of supercooled austenite (PA) in different temperature regions and, therefore final structure and properties of the product. At the same time, in practice, heat treatment is widely used the concept of hardenability of steel"which is a derived characteristic from the UPA, because UPA in region I and II stages of its collapse, in particular steel determines the degree of hardenability (the depth of the hardened zone) (Gulyaev A.P.]. M.: Metallurgiya, 1986. 542 S.; Kachanov NN. The hardenability of steel. M.: metallurgy, 1978, 284 S. and others). Knowledge of the hardenability of steel is mainly used in mechanical engineering for products subjected to tempering and quenching, whereas for a large group of products from small and medium-carbon steels with ferritic-pearlitic structure, the question of the penetration depth of the hardened zone (hardenability) is not interesting to the ECA, because they are not exposed even when the accelerated cooled and quenched to martensite. For these, primarily hot-rolled products (sheet, rebar, structural shapes, pipes, etc.) requires not only a detailed view about the UPA steel, but its changes under the influence of various effects, in particular the stress-strain state during hot plastic deformation. For the practice of the manufacture of hot-rolled products requires knowledge of the impact on sustainability of the PA sign and magnitude of the applied stresses in a certain temperature region of influence, which actively influence the collapse of the PA. In this case, the application is available in the literature (Popov LE, A.A. Popov, Charts the transformation of austenite in steels and beta solution in titanium alloys: a Handbook of heat-treater. M.: metallurgy, 1991. 503 S. and other) data on the UPA does not give the real picture of the kinetics of the transformation and degradation products; Such data is not available in the literature and, primarily, due to the lack of reliable experimental methods for their evaluation. A known method for determining hardenability by the method of trial quenching samples (Kachanov NN. The hardenability of steel. M.: metallurgy, 1978, s)used for steels with a low hardenability is low UPA. In this way hardenability, and hence the UPA can assess the performance by quenching of a series of cylindrical samples, the length of which is four times the diameter. The result of the operations is the construction of the curve of distribution of hardness in the sample section in the coordinates of the "hardness-the distance from the center of the sample. However, the low sensitivity of the method eliminates the possibility of its application to alloyed steels, and a great complexity to use it for mass testing. The closest in technical essence to the proposed method is the method of determination of UPA and, in particular, hardenability, according to the method of the mechanical hardening (GOST 5657-69. The steel. Method of test for hardenability; ASTM A255-02. Standard methods of determining hardenability of steel), selected as a prototype. The method consists in performing the following operations: - heating of the sample to the temperature of formation of austenite; - cooling the heated sample stream of water from the end; - measurement of hardness on so removed two diametrically opposite surfaces at different distances from the chilled water butt; - the construction of the dependence of the distribution of hardness along the length from the cooled end. In the face of hardening creates a velocity gradient cooling along the length of the sample (from the maximum value in the water-cooled end to a minimum at the opposite), which leads to the formation of the whole spectra products of transformation of undercooled austenite with different hardness: martensite, decay products in the second stage (bainite) and stage I (excessive ferrite and perlite). Investigated the impact of (changes in the chemical composition of steel, the temperature of austenitization) will change the UPA, and therefore, the distribution of hardness along the length of the sample by changing the ratio of the decay products of supercooled austenite. The analysis of the constructed curve "hardness is the distance from the cooled end together with metallographic study allows along with hardenability (the depth of the hardened zone) to determine the UPA in different temperature intervals of its transformation. The disadvantage of this method is that the determination of UPA is performed on samples that are not experiencing any stress-strain impact either upon heating or upon cooling, therefore, the use of this method does not allow to investigate the influence of the UPA stress-strain state (i.e. the magnitude and sign of the applied voltage) of the sample in the cooling process at preset speeds in different temperature regions. The technical problem solved by the invention is to determine the impact of the sign and magnitude is applied to the cooled sample voltages on UPA small and medium-carbon steels for the purpose modes of plastic and heat is Brabec hot rolled products. The problem is solved due to the fact that the method of determining the stability of the supercooled austenite of small - and medium-carbon low-alloy steels involves heating the sample to a temperature of formation of austenite, the application to the sample load a particular character and values, followed by cooling with a water jet end of the sample in the loaded condition, the measurement of hardness along the length of the sample so removed two diametrically opposite surfaces, the construction and analysis of the distribution curve of hardness, i.e. according to the invention the sample is subjected to stress-strain effect in the cooling process, and by changing the position of the distribution curves of hardness after cooling assess the impact of the sign and magnitude of the applied stresses on the stability of supercooled austenite, and also hardenability. At the same time as the reference sample of the same shape and size, made of the same material and have experienced the same thermal operations without the stress-strain effects. The stress-strain effects on the sample in the austenitic condition simulates real technological processes used in the production of hot-rolled products (sheet, strip, tubes, profiles and other). The invention is illustrated by the following drawings. p> 1 schematically shows a plant for the implementation of the proposed method for the determination of the UPA, on figa and 2B shows two types of the samples, figure 3 presents the curves of distribution of hardness along the length of the sample after different effects on him.Device for determination of UPA (figure 1) contains a frame 1, a movable gripper 2, the nozzle 3. Heated to the required temperature of the sample 4 is clamped in the grips of the frame 1 of the testing machine and by means of the rolling grip 2 is subjected to stress-strain effects in the application of tensile (compressive) load P is a certain value while cooling in an installation for the mechanical hardening. Cooling (quenching) according to GOST carry out a jet of water coming to the end of the sample through the nozzle 3. The applied sample, as in the prototype, has a cylindrical shape and the dimensions given on figa and, if necessary, for example, when applying tensile stresses - the form shown in figb. The hardness measurement is carried out on the lateral surfaces of the cooled sample, previously so removed to a depth of 1-2 mm for removing de-carbonized layer, then built the curves of distribution of hardness along the length of the standard and sample coordinates: hardness (y-axis) distance from the cooled end (along the axis of the abs is ISS). Figure 3 shows the curves of distribution of hardness along the length of the standard and the sample, experienced mechanical hardening according to GOST 5657-69 after: 1) austenitization at 850°C, 0.5 h (standard); 2) austenitization at 850°C, 0.5 h followed by imposition of a tensile load P=40 kN, which causes stress-strain state of the sample. The curves indicate the flow of the collapse of the supercooled austenite in I, II and martensitic steps. The analysis of these curves shows that the stress-strain state has a significant impact on UPA: curve 2 in the collapse of the I and II stages (l=7-29 mm) lies below the curve 1, which indicates an accelerating influence of the stress-strain state on the collapse of the PA in these areas. More detailed information can be obtained in the manufacture of the sections on the lateral surfaces of the sample and conducting metallographic studies. Thus, the proposed method allows us to determine the change of URA small and medium-carbon steels under the influence of the stress-strain effects, allows reasonably assign modes of plastic and heat treatments to obtain the desired level of properties of the products. The method of determining the stability of the collapse of the supercooled austenite in low - and medium-carbon steels, including the surrounding heating of the sample to the temperature of formation of austenite, subsequent cooling of the sample, measurement of hardness along the length of the sample at two diametrically opposite surfaces, the construction of the curve of distribution of hardness along the length of the sample, characterized in that, to accelerate the decomposition of austenite sample during cooling is subjected to stress-strain effects.
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