Method to assess extent of embrittlement of materials of vver-1000 reactor vessels caused by thermal ageing

FIELD: power engineering.

SUBSTANCE: reactor vessel steel samples are heated to temperature from 300°C, their further ageing is carried out at this temperature within certain time, subsequent tests of samples are carried out for impact bending, and test results are analysed to determine the value of the shift of critical brittleness temperature, at the same time samples of reactor vessel steel in process of ageing at the temperature of reactor vessel operation of 300-320°C are additionally exposed to neutron radiation with flux of 1011-1013 n/cm2·sec for 103 hours, after that they perform baking at the temperature of 400-450°C with duration of at least 30 hours, and assessment of extent of steel embrittlement is determined using the value of shift of critical brittleness temperature ΔTk(t) as a result of thermal ageing for the time making more than 5·105 hours, in accordance with a certain mathematical expression.

EFFECT: increased accuracy of assessment of extent of embrittlement of VVER-1000 reactor vessel embrittlement as a result of thermal ageing.

3 tbl

 

The invention relates to the field of materials research radiation methods, for example by means of neutron irradiation for the detection and creation of local defects and can be used in the nuclear industry to predict the safe operation of nuclear reactors.

Currently, in our country are operated by 8 blocks reactors operating under pressure with a water coolant: VVER-1000. One of the factors that determine the resource reactor (KR)is the impact of elevated temperatures on materials irradiated and neobluchennykh parts of CU, i.e. thermal aging.

The results of studies of thermal ageing of materials used for the manufacture of the WWER-1000, presented in the technical literature [1-10]. It was shown that the base metal exposed parts of the CU VVER-1000 (steel NF) according to [4-7] are subject to thermal aging, and the weld metal CU VVER-1000 according to [4] are not susceptible to thermal aging. As has been shown in studies [4-7], the mechanism of thermal ageing in steel HF caused by the deposition process and subsequent coagulation of the carbides. The absence of thermal aging is usually associated with low carbon content in the weld metal (CC≤0,07%, where CC- carbon content in wt.%), and as a consequence, there is no the of carbide precipitation during operation. At the same time, in [8-10], it is shown that for weld metal steel ANF there is a dependence of the shift of the critical temperature of brittleness from time ΔTk(t)non-zero: if t>105hours ∆ Tk≈20°C, a max ΔTk(t)≈30°C. This result is obtained on the basis of processing results of the tests of thermal sets of specimens CU VVER-1000 and says, apparently, on the allocation of a process of operation of any other phases, except carbides, and/or about the absence of their full coagulation. Perhaps this result is associated with segregation processes of phosphorus.

It should be noted that when the operating temperature Tperfo=(300÷320°C "carbide" and "phosphorus" embrittlement are not cumulative, as these processes are shifted in time. Thus, the maximum ∆ Tkwhen carbide embrittlement corresponds to the time when the phosphorus embrittlement little. With increasing time t ∆ Tkdue to the "carbide" aging, decreases, while the phosphorus embrittlement continues to grow.

At the same time, the materials neobluchennykh parts (the nozzle) CU VVER-1000 can have a high phosphorus content compared to the exposed parts of the CU (shell active zone and the supporting shell). The materials most loaded parts of the reactor (area of pipe) the phosphorus content can be achieved (according to the SPECS) to C P=0,020% (CPthe phosphorus content in wt.%).

Given that today the task of extending the service life of VVER-1000 not less than 60 years (~5·105hours), and the new CR designed for a period of more than 60 years, the question arises about the reliability of the prediction of thermal ageing of CU metal.

Made estimates based on the kinetics of segregation of phosphorus at grain boundaries, and the relationship of these segregation with a critical temperature of brittleness show that for steel reactor containing phosphorus 0.020 wt.% and for weld metal with a Nickel content of 1.90 wt.% and with phosphorus 0.010 wt.% at a temperature of 320°C and holding time of 5·105hours of shift of the critical temperature of brittleness of steel may exceed 40°C.

One of the most important moments used in the estimation of the shift of the ductile-brittle transition temperature of the materials CU, requiring justification, is the value of the equilibrium segregation of phosphorus at grain boundaries or phase boundaries at the operating temperature of the reactor vessel. It is clear that this dependence is almost impossible to verify experimentally, since the temperatures corresponding to the operating temperature of the reactor, the time to reach equilibrium segregation of phosphorus more than 106hours.

In this regard, the urgent task is to develop a CSP is both embrittlement evaluation of the critical temperature of the material of the reactor at the operating temperature of 300-320°C for 5·10 5and more hours.

Known closest analogue to the technical nature and adopted for the prototype "Method of determining the shift of the ductile-brittle transition temperature due to thermal aging"set forth in the "calculation Standards on the strength of the equipment and pipelines of nuclear power installations PNAE G-7-002-86" of the USSR State Committee for supervision of safe working practices in the nuclear industry (Gosatomenergonadzor the USSR), Moscow, Energoatomizdat, 1989 str-201.

The essence of the method adopted for the prototype, is that thermal aging is subjected to the sample vessel steels at a temperature of not more than 100°C higher than the calculated one (350°C) operating temperature reactor. Samples kept at this temperature for 500, 1000, 3000, 7500 and 10000 hours, then they are tested for impact strength, and the shift of the ductile-brittle transition temperature due to thermal aging is determined by the formula:

ΔTt=TCT-Tk0,

where TCT- the critical temperature of brittleness of the material subjected to thermal aging; Tk0- a critical temperature of brittleness of the material in the initial state (before aging).

While calculated values of ∆ Ttfor the duration of use not more than 105hours determined by empirical dependence in which the time of operation δ t t=f(t).

The disadvantage of this method is inadequate assessment of the degree of embrittlement of the steel of the reactor vessel due to thermal aging, as the method does not include the effect of segregation processes of phosphorus at a temperature during operation of the reactor VVER-1000 for 5·105and more hours.

The technical result of the invention is to improve the accuracy of the assessment of the degree of embrittlement of the steel reactor due to thermal aging in operation for 5·105and more hours.

The technical result of the invention is achieved by that in the method of estimating the degree of embrittlement of the materials of the WWER-1000 due to thermal aging, including heating of the steel samples of the reactor vessel to a temperature above 300°C., further aging at this temperature for a certain period of time, subsequent samples were tested for impact strength and the analysis of test results to determine the magnitude of the shift of the ductile-brittle transition temperature, according to the invention, samples of the steel of the reactor vessel in the aging process at the operating temperature of the reactor 300-320°C optionally subjected to neutron irradiation flux 1011-1013n/cm2·sec for 103hours afterwards annealing in which the temperature of 400-450°C for a period of not less than 30 hours, and the assessment of the degree of embrittlement of steel is determined by the magnitude of the shift of the ductile-brittle transition temperature ∆ Tk(t) due to thermal aging during the time of more than 5·105hour, according to the formula:

ΔTk(t)=(Tk-Tk0)[1-exp(4Defft)erfc(2Defft)],

where ΔTkthe shift of the ductile-brittle transition temperature, due to thermal aging; t is the exposure time at temperature aging; Tk0- the value of the critical temperature of brittleness resulting from testing of the material in the initial state;andTk- value of Tkat t=∞, where Tk- the critical temperature of brittleness,

based on the results of tests for impact strength according to the criterion of 47 j,T kdetermined by the results of tests of annealed after irradiation of metal; Deff- the effective diffusion coefficient of phosphorus,Deff=Dγ2d2where D is the diffusion coefficient of phosphorus is dependent on the temperature; d is the thickness of the grain boundaries,γ=Cp/Cpv,whereCpv- volumetric concentration of phosphorus in at.%;Cpthe concentration of phosphorus at phase boundaries and / or grain boundaries at time t=∞ (equilibrium concentration at a given temperature);

Tk=ΔTklim[1-exp(4DeffFtaboutbl)e/mi> rfc(2DeffFtaboutbl)]+Tk0,

whereDeffF- the effective diffusion coefficient during irradiation,DeffF=DFγ2d2DFis the diffusion coefficient of phosphorus in irradiated material, DFis a function of the flux of neutrons;ΔTklim- residual shift of the ductile-brittle transition temperature ofΔTklim=Tklim-Tk0whereTklim- the value of the critical ones is the temperature brittleness, the resulting test material, annealed after irradiation.

The main idea of the new method is to create an artificial acceleration of segregation processes by neutron irradiation directly at the operating temperature of Tperfo. In contrast to accelerate segregation processes by increasing temperature, neutron irradiation practically does not change the value of the equilibrium segregation of phosphorus. At the same time, neutron irradiation accelerates the formation of segregation of phosphorus due to radiation-stimulated diffusion.

The mechanisms of irradiation embrittlement is caused by hardening of the material due to the formation of dislocation loops and precipitates, which leads to the relief of the origin and development of microcracks due to the increase of the effective stress, create additional microcracks in the body of the grain and increase the likelihood of the formation of dislocation clusters of barriers, which nucleate microcracks. The mechanism leading to the hardening associated with segregation, mainly phosphorus at phase boundaries carbide-matrix and at grain boundaries. This mechanism facilitates the nucleation of microcracks at phase boundaries, and facilitates their development at the grain boundaries.

It was established experimentally that the General mechanism of development is pivonia metal during thermal aging and neutron irradiation is the segregation mechanism, which accelerates the diffusion of phosphorus. This acceleration is due to the fact that the diffusion of phosphorus, mainly occurs by vacancy method. When the diffusion coefficient is greatly increased due to the generation of point defects under neutron irradiation.

Comparing the values of the diffusion coefficient in the initial state and after neutron irradiation, it was found that neutron irradiation leads to an increase of the diffusion coefficient of more than 103time flux ~1,0·1011n/cm2·sec and more than 10stime flux ~1,0·1013n/cm2·sec.

Therefore, subjecting the material to the neutron irradiation at a temperature aging (the operating temperature of the reactor vessel 320°C) very limited time, for example, 103hours a flux of 1011-1013n/cm2·sec (which corresponds to the rate of exposure of the material in power or research reactors), segregation of phosphorus at phase boundaries and grain boundaries will correspond to segregation formed without exposure during the 106-108hours, i.e. more than 100-10000 years. Therefore, neutron irradiation allows to artificially accelerate the segregation of phosphorus and get the ultimate assessment of the degree of embrittlement of the material segregation mechanism due to thermal aging.

The outfit is from embrittlement by "segregation" mechanism resulting from neutron irradiation of the metal undergoing embrittlement by "hardening" the mechanism.

Therefore, in order to "select" only "segregation" mechanism, it is necessary to exclude "hardening" mechanism.

Experimentally it was found that after annealing of radiation at a temperature T>400°C for a period of not less than 30 hours leads to almost complete removal of the material hardening that occurred during irradiation.

When the annealing temperature 400-450°C does not occur dissociation of phosphorus segregation, formed upon irradiation, the materials of the CU containing phosphorus more than 0.01 wt.% and Nickel is more than 1.0 wt.%. As a result, the metal after irradiation and annealing will fit extremely aged metal during thermal aging, where the dominant factor is "segregation" mechanism of hardening due to grain boundary segregation of phosphorus.

Test annealed after irradiation of the material allows to determine the marginal evaluation of embrittlement of the material segregation mechanism for time, far exceeding all possible experiments (>100 years). To determine the maximum possible value of the critical temperature of brittleness ofTkfor material in aged condition and the prediction of ∆ Tk(t) due to thermal aging for 5·105and Bo is her hours by calculation using equation McLean and dependencies, describe thermally activated radiation-induced diffusion of phosphorus.

Specific example:

as object of research was used steel grade HF used for manufacturing the reactor, the specific chemical composition of which is given in table 1.

Table 1.
The chemical composition steel grade HF
SteelThe content of elements, wt.%
SiMnCrNiMoVSPCu
HF0,160,300,442,101,150,520,100,160,180,14

The investigated steel was made in the form of rent. Heat treatment of rent, which can be found in table 2, corresponds to the heat treatment according to the prototype for the shells of the buildings of the VVER-1000. To determine the ductile-brittle transition temperature were used samples of Charpy V-neck cut 10×10×55 mm, cut from the middle third of the thickness distribution and surface layers. The value of the ductile-brittle transition temperature was determined by the level of toughness, 47 J.

Table 2
The preliminary heat treatment of steel HF
Steel gradeThe heat treatment
HF915-930°C, vyd. 5 p.m., cooling-water, 645-660°C, vyd. 25 hour, 640°C, vyd. 20 h., the cooling oven to 300°C

In each batch was not less than 12 samples. The ageing time was chosen in such a way as to exclude a significant contribution "carbide" aging and the shift of the critical temperature of brittleness. At the time of aging less than 10 hours "carbide" aging is still very little, and when more than 103hours have very little, because the peak of the "carbide" aging has already passed. The parameters of the proposed and known ways to determine embrittlement of steel for the reactor vessel due to displacement of Crete is at risk of brittle transition temperature and the test results are summarized in table 3. It is believed that the material is not susceptible to thermal aging, if ∆ Tk≈0°C as at T=320°C and at T=450°C. the Steel is exposed to thermal aging, if at least at one temperature ΔTk>0°C.

Table 3
The results of determining the amount of shift of the critical temperature of brittleness of steel MF on offer and the known methods (at Tk0=-40°C)
MethodThe parameters of the methodThe shift of the ductile-brittle transition temperature, °C
AgingIrradiationAnnealing
TemperatureDuration, hours.F. n/cm2·secTemperature, °CDuration, hours.
3001031011400304,5
101345035,6
3201031011400305
101345036
320103---3
450*103---16
Note:
The results of the shift of the ductile-brittle transition temperature averaged not less than three samples per point;
* - According to the Prototype, the value of ΔTkcan be defined on the basis of the test results for samples aged at T=Tcalc+100, where Tcalc=350°C for CU VVER-1000.

The technical effect of using the proposed method of assessing the degree Krups the training materials of the reactor due to thermal aging in comparison with the prototype will help increase the reliability of operation of the WWER-1000.

Literature:

1. Utevsky L., Glickman EA, Kark Gosobraztsa temper embrittlement of steel and iron alloys. M.: metallurgy, 1987. 222 S.

2. Balandin Û.F., I.V. Gorynin, Zvezdin SCI, Markov VG Structural materials AASM: Energoatomizdat, 1984. - 280 S.

3. Kark G.S. Metallography and heat treatment of special steels and alloys for engineering. TSNIITMASH. M.: 1978, No. 142, pp.5-12.

4. Norms based on the strength of the equipment and pipelines of nuclear power installations. PNAE G-7-002-86, M.: Energoatomizdat, 1989, 525 S. - Prototype (str-201).

5. Astaf'ev A.A., Yukhanov VA, Suir ROAD is the Study of the kinetics hermetische aging and its impact on the susceptibility to brittle fracture of RPV steels. / Metallography and heat treatment of metals, No. 2, 1988, s-15.

6. Intered V.M., shneiderov BORN, Suir ROAD and other Structural mechanism for the development of thermal embrittlement in steel with structure bainite. / Metallography and heat treatment of metals, No. 1, 1992, pp.2-6.

7. Yukhanov VA, Suir ROAD is the Study of thermal ageing of RPV steels for nuclear power plants with the aim of justifying resource equipment for up to 60 years. / Metallography and heat treatment of metals, No. 7(613), 2006, p.23-27.

8. B.Z. Margolin, Nikolaev V.A., Yurchenko E.V. Nikolaev Y.A., Eric DU, Nikolaev AV / Analysis embrittlement of materials is of arbusov of VVER-1000 reactors in operation // Problems of materials science. - 2009. No. 4(60). - p.108-123.

9. B.Z. Margolin, Nikolaev V.A., Yurchenko E.V. Nikolaev Y.A., Eric DU, Nikolaev A.V. / a New approach to the description obruniwaru materials of the WWER-1000 during operation // problems of strength. - 2010. No. 1. - page 7-26.

10. B.Z. Margolin, Nikolaev V.A., Yurchcnko E.V. Nikolaev Yu.A., Erak D.Yu., Nikolaeva A.V., Int. J. Pres. Ves. & Piping, 89 (2012), p.178-186.

The method of assessing the degree of embrittlement of the materials of the WWER-1000 due to thermal aging, including heating of the steel samples of the reactor vessel to a temperature of from 300°C., further aging at this temperature for a certain period of time, subsequent samples were tested for impact strength and the analysis of test results to determine the magnitude of the shift of the ductile-brittle transition temperature, characterized in that the steel samples of the reactor vessel in the aging process at the operating temperature of the reactor 300-320°C optionally subjected to neutron irradiation flux 1011-1013n/cm2·sec for 103hours, after that make an annealing at a temperature of 400-450°C for a period of not less than 30 hours, and the assessment of the degree of embrittlement of steel is determined by the magnitude of the shift of the ductile-brittle transition temperature ∆ Tk(t) due to thermal aging during the time of more than 5·105hour, according to the formula:

where ΔTkthe shift of the ductile-brittle transition temperature, due to thermal aging,
t is the exposure time at temperature aging
Tk0- the value of the critical temperature of brittleness resulting from testing of the material in the initial state,
Tk- value of Tkat t=∞,
where Tk- the critical temperature of brittleness, obtained from the results of tests for impact strength according to the criterion 47 J.,
Tkdetermined by the results of tests of annealed after irradiation of metal,
Deff- the effective diffusion coefficient of phosphorus,Dmi> eff=Dγ2d2where
D is the diffusion coefficient of phosphorus, depending on temperature,
d is the thickness of the grain boundaries,
γ=Cp/Cpv,whereCpv- volumetric concentration of phosphorus at.%),
Cpthe concentration of phosphorus at phase boundaries and / or grain boundaries at time t=∞ (equilibrium concentration at a given temperature),
Tk=ΔTklim[1-exp(4DeffFtaboutbl)erfc(2DeffFtaboutbl)]+T k0,
whereDeffF- the effective diffusion coefficient during irradiation,DeffF=DFγ2d2,
DFis the diffusion coefficient of phosphorus in irradiated material, DFis a function of the flux of neutrons,
ΔTklim- residual shift of the ductile-brittle transition temperature ofΔTklim=Tklim-Tk0where
Tklim- the value of the ductile-brittle transition temperature obtained in the test material, annealed after irradiation.



 

Same patents:

FIELD: process engineering.

SUBSTANCE: invention relates to monitoring the flue gas composition. This method is suitable for monitoring of steam boiler operation at burning the chlorine-containing fuel. It can also be used at pyrolysis, gasification and the like processes. Composition of flue gases resulted from thermal processes, particularly, at combustion of biological fuel or fuel produced from wastes is monitored by measurement of quantity of particles of definite sizes at, at least, one point in flue gas path. Measured are particles of sizes that are known to be composed of alkaline metal chlorides.

EFFECT: monitoring of alkaline metal chloride compositions in flue gases.

9 cl, 6 dwg

FIELD: physics; control.

SUBSTANCE: invention relates to space, aviation, radio engineering, instrument-making and mechanical engineering and can be used in all industries for automatic control of the thermal state and functional parameters of technical devices. The method for automatic control of the thermal state and functional parameters of technical devices involves setting and determining the type and parameters of thermal functions of technical devices, from which values of thermal functions during operation of the devices and downtime thereof are calculated, and making adjustments in actuating devices through a numerical control computer system upon reaching the calculated values of set acceptable values. The method involves determining the type, the time variation characteristics of standard laws of thermal functions of the position, movement and state of technical devices, heat-loaded parts thereof, assemblies and components during heating and cooling thereof for each controlled functional parameter during operation of a technical device and during downtime thereof. Statistical characteristics of the time variation of thermal functions of heating and cooling for each controlled functional parameter during operation of the device and during downtime thereof are established during multiple tests. The obtained characteristics of the time variation of thermal functions in the working volume of the technical device during operation and downtime thereof are then used to calculate the value and/or position and/or movement and/or state of the controlled functional parameter in accordance with the operating time or downtime, for the current range of positions, movements and states of heat-loaded parts, assemblies and components of technical devices, and when values and/or positions and/or movements and/or states reach, with given probability, set acceptable values, the controlled functional parameter of the technical device is adjusted through a numerical control computer system by changing and acting on current parameters and functioning characteristics which define the level of the thermal conditions or state of heat-loaded devices.

EFFECT: high accuracy of functioning of technical devices, high reliability thereof, stability of maintaining the level or range of values of functional output parameters of the position, movement and state of technical devices during operation thereof, carried out without using additional mechanisms, devices and systems for measuring temperature and/or thermal deformations and/or the position and/or movement and/or state of heat-loaded parts of devices.

6 dwg

FIELD: measurement equipment.

SUBSTANCE: device comprises: a sensor comprising a sensitive element and a heating element configured for heating of the sensitive element to the previously set operating temperature, besides, the sensitive element is perceptive to the specified gas so that at least one electric property of the sensitive element varies depending on presence of the specified gas, besides, the electric property of the sensitive element is measured by a gas metering device; and a control circuit comprising a heating element controller connected to the heating element and measuring its electric property, besides, the control circuit has a source of heating energy supplying energy to heating element. The controller of the heating element is connected with a source of heating energy and controls its operation depending on measurement of the electric property of the heating element; a facility of pulse modulation connected with the controller of the heating element, the source of heating energy for control of the energy value supplied to the heating element. At the same time the facility of pulse modulation is made as capable of generation of the first set of energy pulses, having certain duration, and the second set of energy pulses, having another, shorter duration for maintenance of temperature of the heating element substantially at the permanent level. Also the invention relates to the method for manufacturing and method of operation of the gas metering device.

EFFECT: device is manufactured and operated in a profitable and reliable manner.

8 cl, 5 dwg

FIELD: physics.

SUBSTANCE: method of determining dryness of wet steam involves measuring pressure in a controlled stream of steam. A steam sample is then collected from the controlled stream, the collected sample is throttled into a flow chamber and calculations are carried out based on the measured parameters. The collected steam sample flows from the first flow chamber into a second flow chamber. Both chambers are placed in the controlled stream of steam or other heating medium. Pressure and temperature is measured in each chamber. After the second chamber, flow rate, pressure and temperature of the collected sample is measured. The value of flow rate is then established based on parameters measured in the first chamber.

EFFECT: determining dryness of a stream of wet steam without condensing the collected sample.

1 dwg

FIELD: measurement equipment.

SUBSTANCE: sample is heated to temperature of polymer binder decay. Filler content is calculated by variation of a sample mass, taking into account the ash residue in process of polymer binder decay defined under conditions identical to composite decay. At the same time the variation of the sample mass is defined according to a thermogram.

EFFECT: higher accuracy of detection of filler content in a polymer composite, reduced time of analysis, lower labour and power inputs.

3 dwg

FIELD: measurement equipment.

SUBSTANCE: method to display a temperature field of an object includes measurement of temperature in different points of its surface. Previously an object image is introduced into a computer base, and the image is displayed onto the screen, the points of temperature measurement on the surface of the object are displayed on the object image on the monitor screen, and after performance of measurements and treatment of results of measurements in the computer the image of the temperature field of the object is formed on its image with software.

EFFECT: simplified design of technical facilities used to vary temperature field of an object.

6 cl, 1 dwg

FIELD: testing equipment.

SUBSTANCE: sample of a lubricant material of permanent volume is heated with mixing in presence of air, measured, and the light flux absorption coefficient is determined. At the same time, at first each sample of the lubricant material is pre-heated for a continuous period of time at atmospheric pressure and fixed temperature, which in process of each subsequent test of a new sample is increased, and after each heating a sample of a lubricant material is taken with permanent mass, which is then heated with mixing in presence of air within the time established depending on the base under permanent temperature and permanent speed of mixing, which after oxidation is measured, the light flux absorption coefficient is determined. Then the graphical curve is built for dependence of the light flux absorption coefficient on heating temperature. Thermal-oxidative stability of the lubricant material is defined by heating temperature with least value of the light flux absorption coefficient.

EFFECT: higher accuracy of determination of thermal-oxidative stability of lubricant materials.

1 dwg

FIELD: machine building.

SUBSTANCE: proposed method comprises heating the part to temperature whereat pressure of released gas expanding under the coating exceeds yield point of coating material to define gas content in part surface from relative area of coating swell.

EFFECT: faster, simpler and cheaper procedure.

1 ex

FIELD: heating.

SUBSTANCE: in the method for determining the system of heat-engineering properties of rooms of buildings and facilities under full-scale (operating) conditions, which involves measurement of inside and outside air temperature, relative air humidity is measured inside the room and temperature is measured on internal surface of enclosing structures; dewpoint temperature and rated temperature is determined; the above temperatures are compared and that parameter is chosen, which has maximum value; the chosen value is used in radiation thermometer as lower alarm limit; radiation thermometer is used with pre-set alarm mode for investigation of the controlled zone in order to detect points with minimum temperature; density of heat flow passing through those structures is measured at those points, and corrected resistance to heat transfer of enclosing structures is calculated.

EFFECT: providing possible evaluation of heat-engineering characteristics of rooms and heat protective properties of enclosing structures under non-stationary conditions using minimum amount of recording instruments at maintaining the accuracy and increasing the monitoring efficiency.

4 cl, 1 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: method of determining desorption activation energy involves heating adsorbent samples; recording cumulative variation of the mass of the sample with temperature and time using a derivatographic method in non-isothermal conditions; determining extremum temperature of the desorption process; plotting a curve in coordinates of calculating desorption activation energy using the formula Eac=19.11 tg α·ξ, where tg α is the tangent of the slope of the straight line plotted in coordinates of ξ is the ratio of scales on the abscissa axis to scales on the ordinate axis; h is the deviation of curve of cumulative variation of the mass of the sample from the neutral axis; F is the area under the curve of cumulative variation of the mass of the sample, bounded by the neutral axis; f is the area under the curve of cumulative variation of the mass of the sample at any moment in time; T is absolute temperature; n is the order of reaction; a portion of adsorbent weighing 20-100 mg is used for heating; the adsorbent has dispersity of 3-7 mcm and is pre-saturated with a sorbate; heating is carried out in the temperature range of 50-400°C.

EFFECT: high reliability and accuracy of determining desorption activation energy.

1 cl, 1 tbl, 2 dwg

FIELD: measurement technology; material quality control.

SUBSTANCE: method involves testing lubricant material sample in presence of air with stirring constant volume under optimum temperature selected with its dependence on lubricant base and a group of operational properties during a time interval characterizing equal oxidation degree taken into account. Acting in equal time intervals, absorption coefficient is measured for luminous flow absorbed by oxidized lubricant material by applying photometry methods. Viscosity and thermal oxidative stability coefficient Ktos are calculated by using relationship like Ktos = Ka μ0in, where Ka is the luminous flow absorption coefficient of oxidized lubricant material; μ0 and μin are the viscosities of oxidized and initial state lubricant, respectively. Graphic dependence of thermal oxidative stability coefficient against luminous flow absorption coefficient of oxidized lubricant material is plotted. Rate of oxidation end products release and their influence upon tested lubricant viscosity growth is determined from plot slope angle tangent with respect to abscissa axis after inflection point. The inflection point coordinates are used for determining the starting point the oxidation end products release begins.

EFFECT: high reliability of estimation method.

4 dwg

FIELD: investigating or analyzing materials.

SUBSTANCE: method comprises determining the values of the inform-parameter for various reference petrols, plotting calibration dependence of the inform-parameter on the octane number, determining the value of the inform-parameter of a sample of petrol to be analyzed, determining octane number of the petrol to be analyzed from the calibration curve, and measuring density and temperature of the sample. The value of the inform-parameter is determined from measuring the surface tension of the sample. The octane number is calculated within temperature range 10-40oC.

EFFECT: enhanced accuracy of determining.

1 tbl cl, dwg

FIELD: investigating or analyzing materials.

SUBSTANCE: method comprises determining composition and concentration of phase in equilibrium two-phase mixture by analyzing heat effects of reactions.

EFFECT: expanded functional capabilities and reduced labor consumption.

FIELD: non-destructive inspection.

SUBSTANCE: temperatures at inner and outer surfaces of tested area of multilayer objects are registered periodically during predetermined time interval. Value of heat conductance coefficient of the layer of interest is set multiple and density of heat flow is calculated which heat flow goes through selected surface of tested area. For any value of heat conductance coefficient the calculated density is compared with really achieved value of density to be determined through he same surface of interest. Then that value of heat conductance coefficient is selected which meets the condition of comparison. Heat flew density is determined by means of reference plate which is mounted onto selected area of tested part. Temperatures at surfaces of reference plate are registered and density of heat flow is determined which goes through surface of reference plate and density of flow through surface of reference plate is determined which surface is adjacent to selected surface of tested part.

EFFECT: improved truth of data.

2 cl, 1 dwg

FIELD: measuring equipment.

SUBSTANCE: thermo-indicating paint is applied to metallic sample of symmetric section, prepared by thermal couples. Unevenly current sample is heated by electric current up to chosen temperature. Current ducts are cooled down concurrently. Sample is exposed for a preset time duration. Sample temperature field is registered. Distances from a chosen point on sample to points of preparation of thermal couples and line of transfer of color of indicator paint are determined. Graph of temperature distribution along sample length is built. Temperatures of color transfer are determined from aforementioned graph.

EFFECT: broader functional capabilities, higher speed of operation.

1 dwg

FIELD: measuring engineering.

SUBSTANCE: method comprises measuring the output signal from the sensor that is set in the reaction chamber in the period of heat relaxation process. The cyclic process is converted into the pseudo-continuous one by means of formation of the transferring process so that to provide the heat-exchange Bio criterion to be constant and its value to range from 0.001 to 0.1. After the completion of the process, the heating is immediately stops. On reaching the concentration balance between the reaction chamber and the ambient fluid, the next heating cycle begins.

EFFECT: decreased power consumption and period of measuring.

1 cl

FIELD: measurement technology.

SUBSTANCE: method can be used for measuring linear expansion coefficient of hard bodies within wide temperature range. Lattice period for whicker crystal is determined preliminary by X-ray method. Change in lattice period is calculated depending on temperature and coefficient to be found is determined while taking mentioned dependence into account.

EFFECT: reduced labor input.

1 tbl

FIELD: thermo-physical research.

SUBSTANCE: subject flat sample of known thickness through heat source of given specific power is brought to heat contact by plane with flat standard sample, having lesser thermal resistance, than subject sample, and additional heat source previously mounted thereon. External surfaces of subject and standard samples with thermo-isolated side surfaces are thermostatted at given temperature and temperature in contact plane is measured. Instead of researched sample, additional standard sample is mounted, identical to main one, efficient thermal resistance of standard samples is determined depending on specific power of additional heat sources in same temperature conditions, at which it is required to determine heat conductivity of subject sample. Then, subject sample is mounted again and specific power of additional heat source is selected, for which efficient thermal resistance of standard sample within error limits coincides with thermal resistance of standard sample, and its heat conductivity is determined.

EFFECT: increased precision.

1 dwg

FIELD: analytical methods.

SUBSTANCE: sample is heated together with pyrite to temperature Tn = (0.45...0.55)(TL-TS)+TS in container with magnesium oxide lock and, before hydrostatic weighing is performed, paraffin layer is deposited onto surface of sample. Summary content of gases is found in terms of following equation: where M1 and M1* are masses of sample before and after heating, respectively, g; M1' mass of sample after heating and deposition of paraffin, g; M2' mass of sample in water after heating and deposition of paraffin, g; V and V' are specific volume of distilled water at temperatures of corresponding weighing, cm3/g; Ta ambient temperature, °C; Th heating temperature of sample, °C; TL and TS are liquidus and solidus temperatures of test alloy, respectively, °C.

EFFECT: increased reproducibility and accuracy in testing aluminum alloy semimanufactured products for summary gas content.

1 dwg, 3 tbl

FIELD: the invention refers to the field of measurements of thermal condition of a solid body and a surrounding medium.

SUBSTANCE: the arrangement has a thermovision chamber and a converter( a sensor for definition of characteristics of heat emission). The sensor is a plate-"wall" of an arbitrary form out of elastic material in which an opening of a corresponding form is made. The form of the plate and the form of the opening are defined by configuration of the investigated field. The both surfaces of the plate are covered with thin layer of material with high thermal conduction - a foil. At that the foil directed to the investigated surface, covers the whole square of the plate of the sensor and the opening it , and from the other side - it also covers the whole square of the plate but it has an opening identical to the opening of the plate.

EFFECT: arrangement allows to define with high degree of accuracy and reliability the meanings of characteristics of thermal emission - a thermal flow and coefficient of thermal emission from a solid body in a gas medium enveloping it and also to cut down expenditures of time and to increase safety of the work of a man at conducting the indicated measurements.

3 dwg

Up!