GB2213355A - Method of determining the quantitative content of admixture in an alloy - Google Patents
Method of determining the quantitative content of admixture in an alloy Download PDFInfo
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- GB2213355A GB2213355A GB8829634A GB8829634A GB2213355A GB 2213355 A GB2213355 A GB 2213355A GB 8829634 A GB8829634 A GB 8829634A GB 8829634 A GB8829634 A GB 8829634A GB 2213355 A GB2213355 A GB 2213355A
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- 229910045601 alloy Inorganic materials 0.000 title claims description 138
- 239000000956 alloy Substances 0.000 title claims description 138
- 238000000034 method Methods 0.000 title claims description 131
- 239000007788 liquid Substances 0.000 claims description 112
- 230000008569 process Effects 0.000 claims description 109
- 238000002425 crystallisation Methods 0.000 claims description 103
- 230000008025 crystallization Effects 0.000 claims description 103
- 229910052751 metal Inorganic materials 0.000 claims description 45
- 239000002184 metal Substances 0.000 claims description 45
- 238000001816 cooling Methods 0.000 claims description 39
- 230000000875 corresponding effect Effects 0.000 claims description 21
- 239000000203 mixture Substances 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 description 17
- 239000010703 silicon Substances 0.000 description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 229910052799 carbon Inorganic materials 0.000 description 7
- 239000011777 magnesium Substances 0.000 description 7
- 239000012071 phase Substances 0.000 description 7
- 230000007704 transition Effects 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 6
- 239000004411 aluminium Substances 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 235000010210 aluminium Nutrition 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 229910052802 copper Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 229910052749 magnesium Inorganic materials 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 4
- 229910001338 liquidmetal Inorganic materials 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000007790 solid phase Substances 0.000 description 3
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 2
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 2
- 229910000846 In alloy Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- QMQXDJATSGGYDR-UHFFFAOYSA-N methylidyneiron Chemical compound [C].[Fe] QMQXDJATSGGYDR-UHFFFAOYSA-N 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- 241001676573 Minium Species 0.000 description 1
- KMWBBMXGHHLDKL-UHFFFAOYSA-N [AlH3].[Si] Chemical compound [AlH3].[Si] KMWBBMXGHHLDKL-UHFFFAOYSA-N 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000009089 cytolysis Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- QEVHRUUCFGRFIF-MDEJGZGSSA-N reserpine Chemical compound O([C@H]1[C@@H]([C@H]([C@H]2C[C@@H]3C4=C(C5=CC=C(OC)C=C5N4)CCN3C[C@H]2C1)C(=O)OC)OC)C(=O)C1=CC(OC)=C(OC)C(OC)=C1 QEVHRUUCFGRFIF-MDEJGZGSSA-N 0.000 description 1
- 208000006379 syphilis Diseases 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/02—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering
- G01N25/04—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering of melting point; of freezing point; of softening point
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/20—Metals
- G01N33/202—Constituents thereof
- G01N33/2028—Metallic constituents
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Pathology (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
Description
METHOD OF DETERMINING QUANTITATIVE CONTENT OF
ADMIXTURES IN ALLOYS
Field of the Art
The present invention relates to means for the inves tigation of petals and more particularly to methods of determining quantitative content of admixtures in alloys.
Prior Art
Widely known in the art are methods of menitoring the content of admixtures in all@ys, based on the thermal sna- lysis.
A method is known for determining the content of carbon and the temperature of liquid steel (SU, A, 804125), resi din; in that uhe ratio of the periods of time between the phase transitions of metal samples cooled with any cons- tant rate with the known carbon content and with the un known carbon content is compared.The rior-art me tnooi is characterized, first of all, by that the requirement of the rate of cooling to be constant is ret only within the range of the metal sample being in a liquid state and is ensured by the external conditions of cooling. In the range of phase transitions, that is, during crystallization, the rate of cooling of the metal sample depends on the external conditions of cooling and on the internal conditions of heat liberation during crystallization.The time between the phase transitions, proportional to the tempersture intervals between the phase transitions derends on the extent to which the process of crystallization is non-ecuilibrium at each stage of the phase transition. In this case the temperature intervals in the process of phase transitions are not strictly constant in alloys with an invariable content of carbon. Said disadvantages bring down the accuracy of determining the content of carbon in iron-carbon alloys. Furthermore, the method has but a limited applicability and may be used only for determining the content of carbon in liquid steel.
A method is known for determining the content of silicon in iron-carbon alloys (SU,A,381996), resioning in that the temperature of phase transitions is treasured and the content of silicon is deternined from the difference between the solidus temperatures of two samples of a liquid alloy, containing equal amounts of an admix- ture, but cooled with different rates.
This method is disadvantageous in that the accuracy of determining the convent of an admixture in an alloy depends on the accuracy of measurin0 the absolute value of the solidus temperature, this accuracy being dependent on the calibration characteristics of thermocouples and their inertiality; moreover, the differences the rates of cooling of both samples cannot be taken into account in numerical for: an4, as a result, the tempera- ture measurement data cannot be processed with the aid of computing facilities which would enhance the rapiUlty of the method.
Disolosure of the Invention
The present invention is directed to the provision of a method of determining the quantitative content of admixtures in alloys, which would ensure rapi@ity of determination of the quantitative content of an admixture by varying the measured parameters and determining, respectively, the temperature differences in the process of cooling and crys@allization, assooiated with the content of the admixture in the alloy with aking into account the rate of cooling of each of the samples of liquid metal and with resorting to computing facilities.
Said object is acoomplished due to the fact that in a method of determining the quantitative content of admixtures in alloys, residing in that temperatures sre measured of a liquid sample of an alloy, in which the content of an admixture is known in the process of c@o- ling and crystallization, and temperatures are measured of a liquid sample of an alloy, in which the content of an admixture is unknown, in the process of cooling and crystallization, according to the invention, the tem- peratures of a liquid sample of pure metal serving as the base of the alloy are measured In the process of coo 1n5 and crystallization, maximum temperature differences are determined at the end of the process of crystallization for the sample of pure metal, for the sample of the alloy in which the content of the admixture is known, and the sample of the alloy in which the content of the admixture is unknown, and for determining the quantitative content of the admixture in the alloy the maximum temperature difference at the end of the process of crystallization for the sample of the alloy in which the content of the admixture is unknown is subtracted from the maximum perature difference at the end of the process of crystal lization for the sample of pure metal, and the maximum temperature difference at the end of the process OT crystallization for the sample of the alloy in which the content of the admixture is known is subtracted from the maximum" temperature difference aQ the end of the process of crystallization for the sample of pure metal,
and the ratio of the first value of the difference to the second one is multiplied bj the quantity of tne a-- mixture in the sample of the alloy in which the content ol the admixture is known, as the maximum temperature
Difference for each sample the difference being adopted between the true temperature of the sample at the moment of completion of the process of crystallization and its temperature calculated for the same foment in the sb- sence of evolution of the latent heat of crystallization.
It is also expedient that in the method of åeter- mining the quantitative content of admixtures in alloys the maximum temperature differences at the end of the process of crystallization for the sample of pure metal, for the sample of the alloy in which the content of the admixture is known, and for the sample of the alloy in which the content of the admixture is unknown should be determined, respectively, as the difference betv;;een the t/emperature of the sample at the end of the crystallize- tion process and the product of the initial temperature for the liquid sample of pure metal, for the liquid sample of the alloy in which the content of the admix- ture is known, and for the liquid sample of tre alloy in which the content of the admixture is unknown by a value calculated from an exponent whose negative index of a power is the product of a coeffIcient characterising the rate of cooling of the corresponding liquid sample and the time of coolies of each sample from the omen of time corresponding to the initial temperature of the liquid sample to the moment of time corresponding to tne temperature at the end of the process of crystallization
The herein-proposed method of determining the quan- titative content of admixtures in alloys is noted for its universality and nay be used for determining the quantitative content of admixtures in alloy of different types. An increase in the accuracy and mazivity of the method is attained by that the determination of the quen- titasive content of the admixture is carried out by proceeding from the temperature differences, the calculation of the temperature differences and of their ratios being performed with the ai@ of computing facilities.
Brief Description of Drawings
In what follows the present invention will be illustrsted by examples of its opecific embodiment with reference to the accompanying drawing in which a diagram of the true temperature variation in the process of cooling and crystallization of a liquid sample of an alloy versus time is shown, as well as a diagram of the calculated temperature variation versus tie for the same liquid sample in the absence of evolution of the latent heat of crystallization, according to the invention.
Best Way of Carrying the Invention into Effect
Now the proposed method of determining the quantity stative content of admixture a in alloys will be considered.
For effecting the method, a liquid sample of an alloy is taken, in t;hich the content of an admixture is known, as ;.ell as a liquiJ sample of an alloy in which the content of the admixture is unknown, and a liquid sample of pure metal constituting the base of the alloy. A corresponding liquid sample is taken from a vessel with a liquid alloy or pure metal vith the aid of a special beaker accommodating a thermocouple connected to a recording instrument, for instance to a digital voltmeter.
For taking a corresponding liquid sample, the beaker is immersed into the vessel containing the liquid metal and heated up to the temperature of liquid metal. After that the beaker filled with the sample of the alloy or pure metal is vithdrawn from the vessel and cooled in air.
In the process of cooling and subsequent crystallization of the liquid sample of the alloy or ure metal the temperature is recorded ;iith the aid of the initial voltmeter and the results of temperature measurements are delivered to a computer, for instance, to a microcomputer which serves for processing the results of temperature @easurements and yielding the results of determining the quantitative content of the admixture in the alloy.
An example of temperature variations in the process of cooling ama crystallization of a liquid sample of an alloy belonging to binary system is shown in the drawing,
herein the temperature values are denoted as Ti and plotted along the Y-axis, while the values s the moments of time of measuring the temperature Ti are denoted as i and plotted along ehe X-axis.Curve 1 shoves the variation of the true temperature r. of the liquid sample of the alloy in the process of cooling and crystallization; curve 2 shows the variation of the calculated temperature
of the liquid sample, calculated from the product of the initial temperature To of the liquid sample, which is established 20-30 seconds before the moment #1 of the commencement of the process of crystallization, by the value of the exponent e, the neative index of the power of which is the product of the coefficient characterizing the rate of cooling of the liquid sample by the time of cooling of the sample from the moment #0 corresponding to the initial temperature To of the liquid sample to the moment #i at which the temperature Ti is measured.
Measuring of the temperature Ti of each corresponding liquid sample in the process of cooling and crystal- lization is described by the following equation:
where T1 is the true value of the liquid sample temperatu- re measured in the process of coolie and crystallization; #i is the moment of time at which the temperature Ti measured;
To is the initial temperature of the liquid sample, from whose value the product Toe α(#i - #o) is calculated; #o is the moment of time at which the temperature To is messured; F1 is the moment of commencement of the process of crystallization; ;
V0 is the volume of the liquid sample of the alloy; V(#i) is the volume of the liquid phase formed in the process of crystallization vithin the time interval from the moment #1 of commenoement of the process of crystallization to the moment of time
is the reletive quantity of the solid phase formed within the time interval from #1 to # L is the latent heat of crystallization of the alloy or pure metal;
C is the average heat cape city of the liquid sample of the alloy or of the liquid sample of cure metal; α is the coefficient characterizing the rate of cooling of the liquid sample of the alloy or pure metal.
From equation (2) it follows that in the process of cooling of the liquid sample of the alloy or pure metal to the moment #1 of the commencement of the process of crystallization the tiue temperature Ti of the liquid sample, measured in the process of cooling of the liquid' sample, is equal to the calculated temperature
Starting vIth the moment F of the commencement of the process of crystallization, the valve of the tempera- ture Ti, measured at the moment of time #i in the process of crystallization of the liquid sample of the alloy in which the content of the admixture is known, of the liqui sample of the alloy in which the content of the admixtare is unknown, and of the liquid sample of pure metal which is the base of the alloy, respectively, exceeds the calculated value of the temperature, corresponding to equation (3), calculated for the moment of time #i, by the value of the integrand and (2)
The value of the integrand addend (2) is proportional to the product
The true temperature T of the sample, measured in the process of crystallization, may be described by the aqua- tion
From equations (2), (3), (6) it follows that the dif- ference of the measured temperature T. from the calculated one, expressed by equation (1), is determined by the evolution of the latent heat of crystallization L as the liquid sample of the alloy or pure metal passes in the process of crystallization over to the solid state ith the formation of a relative quantity of the solid phase, equal to
As in the process of crystallization the quantity of the solid phase V# 2 wormed at the moment of time #i, increases from zero (at the moment of time, corresponding to the moment #1 of the commencement of cystallization) to Vo equal to the volume of the liquid sample of the alloy or pure metal, the relative quantity of the solid chase is determined by equation (7) and varies in the process of crystallization from zero to 1.This @eans that at the moment of time t2 of completion of the ro- cess of crystallization, when V(#2) = V0 the condition
is fulfilled, where T@ is the true temperature of the sample of the alloy or pure metal at the moment completion of the process of crystallization;
is the calculated temperature of the sample of the alloy or pure metal t the moment 72 of completion of the process of crystallization.
From the moment of time #2 of complation of 2he process of crystallization the evolution of the latent heat of crystallization L ceases, this corresponding to the conaition L = 0, and the process of cooling of the solid sample obeys the law described by equation (3).
From equations (2), (3), (o), (8) it follows that in the process of crystallization of the liquid sample of the alloy or pure metal the changes in the calculated va lues of the temperature (1) characterize the process of cooling of the liquid sample in the absence of evolution of the latent heat of crystallization L, the difference between the true temperature T1 measured in the process of cooling and crystallization of the liquid sample and the calculated temperature (1) increasing from zero to the maximum value at the moment of time 2 of completion
OF the process of crystallization, this maximum value being proportional to the ratio of the latent heat of crystallization L to the average heat capacity S of the liquid sample and referred to as the maximum temperature @ifference AT at the end of the process of crystallization of the liquid sample of the alloy or pure zs-tal #T = T1 - T0e-α;(#2-#0) (9) As an increase of the quantity of an sdmixture in the alloy or pure metal brings about a change of the latent heat of ciystallization L of the alloy or pure metal, as well as of the average heat capacity of the liquid sample of the alloy or pure metal, the value of the maximum temperature difference #T at the end of the process of crystallization, corresponding to the liquid sample, vill also depend on the quantity of the admix- ture in the alloy.
The property of the maximum temperature difference AT at the end of the process of crystallization to chase depending on the content of the admixture in the alloy is used in the present invention for determining the augntitative content of the admixture.The method is realized by determining the maximum temperature diffe- rence AT2 at the end of the process of crystallization of the liquid sample of sure metal1 constituting the basse of the alloy, the maximum temperature difference #T3 at the end of the process of crystallization of the liquid sample of the alloy in which the content of the admixture is known, and the maximum temperature difference $T4 at the end of t process of crystallization of the li- quid sample of the alloy in which the content of the adixture is unknown, the quantitative content of the admixture in the alloy being found from the formula
where P% is the unknown quantity of the admixture in the
alloy; Kj-5 is the knov;n quantity of the admixture in the
alloy;
AT2 is the maximum temperature difference at the end of the process of crystallization of the
liquid sample of pure metal constituting the
base of the alloy; #T3 is the maximum temperature difference at the end of the process of crystallization of the liquid sample of the alloy in which the content of the admixture is known; ; #T4 is the maximum temperature difference at the end
of the process of crystallization of the liquid
sample of the alloy in which the content of the
admixture is unknown.
To calculate the maximum temperature difference AT at the end of the process of crystallization of the liquid sample of the alloy in which the content of the admixture is knoun, the maximum temperature difference #T4 at the end of the process of crystallization of the liquid sample of the alloy in which the content of the admixture is unknown, and the maximum temperature difference AT2 at the end of the process of crystallization of the liquid sample of pure metal which constitutes the base of the alloy, itis necessary to determine the coefficient characterizing the rate of cooling of the corresponding liquid sample The determination of the coefficient α; is carried out in the process of cooling of the corresponding liquid sample in the time interval from the moment of time #0 of measuring the initial temperature To to the moment of time #3 of measuring the temperature T6, the value of which is always greater than the corresponding temperature T7 of the commencement of the process of crystallization of the liquid sample of the alloy in which the content of the admixture is knovçn, of the liquid sample of the alloy in which the content of the admixture is unknown and of the liquid sample of 'ure metal constituting the base of the alloy (see the Drawing).The coefficient is calculated from the ratio of the difference between the natural logarithm of the initial temperature ln To and the natural logarithm of the tem erature Tr ln T6 of the corresponding liquid sample to the difference betvJeen the moment of time #3 of measuring the temperature T6 and the moment of time #0 of measuring the temperature To from the formula
where T6 is the true temperature of the liquid sample,
measured in the process of cooling, the value
of which is greater than T5 of the commencement
of the process of crystallization of the corres-
ponding liquid sample of the alloy or pure metal;; #3 is the moment of time of measuring the temperature
T6.
After determining the coefficient for the liquid sample of the alloy in which the content of the admixture is known, or the liquid sample of the alloy in which the content of the admixture is unknown, and for the liquid sample of pure metal constituting the base of the alloy, starting sith the moment of time to of measuring the temperature Tofor each corresponaing liquid sample in the process of cooling and crystallization the product is calculated of the initial temperature To bj the value calculated from the exponent, the negative index of the power of which is the product of the coefficient α; characterizing the rate of cooling of each liquid sample by the time from the moment #0 of measuring the tempera- ture To to the moment of time of measuring the temperature Ti, namely, (1). After that for each corresponding liquid sample of the alloy or pure metal the difference is calculated between the true value of the temperature Ti, measured in the process of cooling and crystalliza- tion, and the calculated te2perauure Toe-α;#i he lif- ference
obtained at the moment of tine #i is compared with the temperature difference obtained at the moment of time #i-## , preceding the moment of time T where## is tne interval between the moments of time of measuring the temperature Ti (see the Drawing). 6 comperison of the temperature difference in the process of cooling of each liquid sample gives the maximum temperature difference
AT and, at the same time, the true temperature I1 at the moment of time of completion of the crystallization process is established.
Presented hereinbelow are examples of determining the maximum temperature difference #T3 at the end of the process of crystallization of a liquid sample of an alu- minium-based alloy comprising 10.5% of silicon (Example 1) and the maximum temperature difference #T2 at the end of the process of crystallization of a liquid sample of aluminium (Example 2), explaining Example 3.
Example 1
Aluminium alloy vith silicon content of 10.5%
Initial temperature To of liquid sample of the alloy
is 747.8 C
Coeffioient α= 0.504x10-2s-1
Time True Calculated Temperature Note inter- tempe- temperature difference val rature @@-α(#i-#@) @ - @ @ -α;(#i-#@) from the T. of o i -o moment T liquid OC to the # sampmoment #i le of alloy (#i-#o),s in the
pro
cess of
cooling
and crys
talliza tion, C 1 2 3 4 5 54.0 569.3 569.27 0.05 Process
of coo55.2 567.0 567.0 0 ling of @iquid 56.4 564.8 564.81 -0.01 sample 57.6 562.6 562.54 0.06 of alloy 58.8 560.5 559.02 1.048 Commen
cement of
crystal
lization
process 60.0 557.0 552.65 4.34 61.2 557.0 549.32 7.68
Example 1 (continued)
1 2 3 4 5
62.4 556.2 546.01 12.19 Process of orys
63.6 558.4 542.72 15.68 tallization of
64.8 558.4 539.44 18.96 liquid sample
66.0 558.4 536.19 22.21
67.2 558.4 532.96 25.44 120.0 557.2 408.44 148.76 121.2 557.2 405.97 151.23 122.4 557.2 405.53 153.67 125.6 557.2 401.09 156.11 124.8 557.0 398.67 158.33 126.0 557.0 396.27 160.73 127.2 557.0 393.88 163.12 170.0 544.2 317.45 226.75 171.2 542.7 315.54 227.16 172.4 540.9 313.64 227.26 ## st the end of the process
of c@ystallization 173.6 539.0 311.75 227.25 Process of cool174.8 536.6 309.87 226.73 ing of soli@ sam176.0 534.3 307.99 226.31 ple of the alloy 177,2 532.0 306.14 225.86
Example 2 (explaining Example 3)
Pure aluminium
Initial temperature To of liqui@ sample of the alloy
is 736.5 C
Coefficient α=0.64x10-2s-1 Time True tem- Calculated Temperature Note interval perature temperature difference from the
Ti of alu- Toe-α#i at Ti-Toe α;#i moment #o minium alto the loy in the the moment
moment #i process of #i, C (#i-#@),s cooling and crystalli
zation, C
1 2 3 4 5 22.4 636.2 638.17 0.03 25.6 628.0 625.12 2.88 Commencement
of the crys
tallization
procese 28.8 628.2 612.52 15.68 32.0 628.4 600.10 28.30 35.2 628.4 587.94 40.40 60.8 626.2 499.09 127.11 64.0 626.0 488.97 137.03 67.2 626.0 479.06 146.94 99.2 621.2 390.34 229.86 99.8 621.0 388.84 231.30 100.4 620.8 387.35 233.44 101.0 620.6 385.87 23@.73 101.6 620.6 384.39 236.21 102.2 620.4 382.92 237.40 102.8 620.2 581.45 238.75 #T at the end
of the process
of crystalliza
tion 103.4 618.0 379.99 238.01
The Example whicy follow illustrate the determination of the quantitative content of silicon (Si, %) In alloys of the "aluminium-silicon" system and of oxygen (0, %) in alloys of the "copper-oxygen" system.
Example 3
For a liquid sample of an alloy of pure aluminium the teacerature difference #T2 at the end of the process of crystallization is 238.75 C and for a liquid sample of an alloy of the aluminium-silicon system, in which the content of silicon is known to be 10.5%, the maximum temperature difference #T3 at the end of the process of crystallization is 227.260 C.
Now versions will be considered, when:
(a) for an alloy of the "aluminium-silicon" system, in which the content of the admixture is unknown, the maximum temperature difference #T4 at the end of the process of crystallization is 232.6 C. The content of silicon in the alloy in which the content of silicon is unknown is found. from formula (10) in the following manner.
238.75 - 232.6
Si% = x 10.5% =
238.75 - 227.26 (b) for an alloy of the "aluminium-silicon" system,
in which the content of the admixture is unknown, the maximum temperature difference #T4 at the end of the crystallizaticn process is 235.12 C.The content of silicon in the alloy in ;which the content of silicon is unknown is found as follows: 238.75 - 235.12
Si % = x 10.5% = 3.32%
238.75 - 227.26 Example 4
In alloys of the "copper-oxygen" system, based on copper the maximum temperature difference #T2 at the end of the process of crystallization for a liquic sample of pure copper is 23J.50C. If for a liquid sample of an alloy in which the content of oxygen is known to be 0.032%, the maximum temperature difference #T3 at the end of the process of crystallization is 212.8 C, then::
(a) in case the maximum temperature difference #T, at the end of the process of crystallization for the liquid sample of an olloy in which the content of oxygen is unknown corresponds to 228.4 C, the content of oxygen in the alloy, according to formula (10), is 230.5 - 228.4
0% = x 0.032% = 0.004%
230.5 - 212.8 (b) in case the maximum temperature difference A 7 at the end of the process of crystallization for the liquid sample of an alloy in which the content of oxygen is unknown corresponds to 219.50C, the content of oxygen in the alloy is:: 0 %= ########### x 0.032 = 0.019% The herein-proposed method of determining the cuan- titative content of admixtures in alloys may be used for determining the content of an admixture of one kind in an alloy containing several kinds of admixtures differing from the one being determined, on condition that the qusn- titative content of these differing admixtures is known and corresponds to the quantitative content of the kinks of admixtures differing from the one being determined in the liquid sample of the alloy in which the content of the admixture is known.As the liquid sale le of pure metal a liquid sample of an alloy is used, which does not contain the admixture the content of which is being determined, with the quantitative content of other kinks of admixtures, differing from the one being determined, the same as in the liquid sample of the alloy with the known and unknown content of the admixture. Example 5 explains the determination of the content of an unknown admixture in an alloy containing several kinds of admixtures.
Example 5
We shall consider a version when an aluminium-based liquid alloy contains the following kinds of admixtures: silicon, copper, iron, and magnesium, the quantitative content of silicon, copper, and iron being knon and equal to 5.1%, 6.9%, and 0.9% respectively, whereas the quantitative content of magnesium is unknown.The maximum temperature difference #T4 at the end of the process of crystallization of the liquid sample of the alloy in which the quantitative content of magnesium is unknown is 219.400. If in a liquid sample of an alloy with the same base the content of magnesium admixture ,s known to be, for example, 0.55% and the content of silicon, copper, and iron corresponds to 5.1%, 6.9%, and 0.9%, and the maximum temperature difference #T3 at the end of the process of crystallization is 213.62 C; in a liquid sample of an aluminium-based alloy in which magnesium is absence, the content of sIlicon, copper, and iron also corresponus to 5.1%, 6.9%, and 0.9%, ann the aaxi:num temperature difference AT, at the end of the process of crystallization is 231.75 C, the quantitative content of magnesium in the alloy in which its content is unknown is found from equation (1t)) as 231.73 - 219.4
Mg % = x 0.55% = 0.37%
231.73 - 231.62 From the foregoing Examples 3-5 it follows that for determining the quantitative content of an admixture in an alloy it is necessary to determine the maximum tempe- rature difference #T4 at the end of the process of crys- tallization of the liquid sample of the alloy in which the content of the admixture is unknown, the maximum temperature difference AT2 at the end of the process of crystallization of the liquid sample of pure metal constituting the base of the alloy, and the maximum temperature difference #T3 at the end of the process of crystallization of the alloy containing the known quantity of the admixture of the same kind. It is necessary that the content of those admixtures which differ from the one being determined should remain constant in all the corresponding liquid samples.
For particular groups of metal-admixture alloys the determination of the maximum temperature difference #T2 at the end of the process of crystallization of the liquid sample of pure metal and of the maximum temperature difference AT at the end of the process of crystallization of the alloy in which the content of the admixture is known may be carried out once and the obtained values of the maximum temperature differences AT2 and AT may be used as the reference values.For determining the unknown quantitative content of the admixture in the alloy it is, tnus, necessary to take one liquid sample of the alloy in which the content of the admixture is unkno.vn, to measure the temperature of the liquid sample in the process of cooling and crystallization, to determine the maximum temperature difference #T4 at the end of the process of crystallization, and to calculate the quanti tatlve content of the admixture from formula ClO). For carrying out the calculations and storing the reference values of the maximum temperature difference AT2 at the end of the process of crystallization of pure metal and of the maximum temperature difference nT3 at the end of the process of crystallization of the sample of the alloy with the known content of the admixture it is necessary to employ the calculating hardware and software, which enhance the rapidity of determining the content of the admixture in the alloy.
The calculation of the coefficient which characterizes the rate of cooling of the corresponding liquid sample, of the temperature differences
and the determination of the maximum tesperature difference at the end of the process of crystallization of the liquid sample of the alloy with the known content of the admixture, of the liquid sample of the alloy with the un known content of the admixture, and of liquid sample of pure metal is realized -::ith the aid of microcomputers and software, the accuracy of finding the maximum temperature difference at the end of the process of crystallization being the higher the smaller the interval At between the measurements of the true temperature Ti of the liquid sample of the alloy or pure metal in the process of cooling and crystallization.
The application of the method of determining the quantitative content of an admixture in an alloy provides a reduction in the number of samples of the liquid alloy in which the content of the admixture is unknown, to be taken, for instance, for the quantitative raid determination of the content of the admixture in the alloy in the process of melting under industrial conaivions, as well as a reduction of the total time of determining the content of the admixture in the liquid alloy.
Industrial Applicability
The use of the method of quantitstive determination of the content of admixture a in alloys in the netallurgi- cal industry and foundry practice makes it possible to adjust the content of an admixture in a liquid alloy directly in the process of melting, to improve the quality of metal in castings, to diminish the consumption of charge materials introduced into the liquid alloy for modifying its composition, and also to adjust the consumption of materials used for refining the liquid alloy.
Claims (2)
1. A method of determining the quantitative content of an admixture in an alloy, residing in measuring the temperature of a liquid sample of an alloy, in which the content of the admixture is known, in the process of cooling and crystallization and the temperature of a liquid sample of an alloy, in which the content of the ad mixture is unknown, in the process of cooling and crystallization, c ha r a c t e r i z e d in that the temperatures of a liquid sample of pure metal constituting the base of the alloy are measured during the process of cooling and maximum temperature differences are determined at the end of the process of crystallization for the sample of pure metal, for the sample of the alloy in which the content of the admixture is known, and for the sample of the alloy in which the content of the admixture is unknown, for determining the quantitative 'content of the admixture in the alloy the maximum temperature difference at the end of the process of crystallization for the sample of the alloy in which the content of the admixture is unknown is subtracted from the maximum temperature difference at the end of the process of crystallization for the sample of pure metal, the maximum temperature difference at the end of the process of crystallization for the sample of the alloy in which the content of the admixture is known is subtracted from the maximum temperature difference at the end of the process of crystallization for the sample of pure metal, and the ratio of the first value of the difference to the second one is multiplied by the content of the admixture in the sample of the alloy in which the content of the admixture is known the maximum temperature difference for each sample being adopted to be the temperature difference between the true temperature of the sample at the end of the process of crystallization and its temperature as calculated for the same moment in the absence of evolution of the latent heat of crystallization.
2. A method as claimed in Claim 1,c h a r 3 c t e r i z e d in that the maximum temperature differences at the end of the process of crystallization for the sample of pure metal, for the sample of the alloy in which the content of the admixture is known, and for the sample of the alloy in which the content of the admixture is unknown are determined respectively as the difference between the temperature of each sample at the end of the process of crystallization and the procuct of the initial temperature for the liquid sample of azure metal, for the liquid sample of the alloy in which the content of the admixture is known, and for the liquid sample of the alloy in which the content of the admixture is unknown by the value calculated from an exponent the negative index of the power of 1iich is the product of a coofficient characterizing the rate of cooling of the coirespon- ding liquid sample by the time of cooling of each sample from the moment of time corresponding co the initial te pe- rature of the liquid sample to the moment of tine, cor responding to the temperature at the end of the process of crystallization.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/SU1987/000049 WO1988008531A1 (en) | 1987-04-24 | 1987-04-24 | Method of determining the quantitative content of admixture in an alloy |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8829634D0 GB8829634D0 (en) | 1989-03-08 |
| GB2213355A true GB2213355A (en) | 1989-08-16 |
| GB2213355B GB2213355B (en) | 1991-04-17 |
Family
ID=21617100
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8829634A Expired - Lifetime GB2213355B (en) | 1987-04-24 | 1988-12-20 | Method of determining quantitative content of admixtures in alloys |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH01503085A (en) |
| DE (2) | DE3790942C2 (en) |
| GB (1) | GB2213355B (en) |
| WO (1) | WO1988008531A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2790090A1 (en) * | 1999-02-24 | 2000-08-25 | Metal Science Ltd | Determination of magnesium content in a molten aluminum-silicon alloy involves thermal analysis of the molten alloy to which phosphorus and/or sulfur has been added, to derive eutectic temperature |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4300495B4 (en) * | 1993-01-13 | 2004-12-02 | BEGO Bremer Goldschlägerei Wilh. Herbst GmbH & Co. | Procedure for testing dental casting materials |
| JP2750832B2 (en) * | 1995-05-16 | 1998-05-13 | 株式会社木村鋳造所 | Method for determining the properties of molten cast iron |
| CN101303319B (en) * | 2007-05-09 | 2010-05-19 | 中国科学院金属研究所 | Thermal analysis detection method and device for microstructure refinement effect of magnesium and magnesium alloy modification |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2059852A5 (en) * | 1970-06-29 | 1971-06-04 | Qualitats Edelstahl Komb | Indirect determination of major components of fused alloy |
| DE2403146C3 (en) * | 1973-02-01 | 1981-10-15 | Dr. K. Ableidiger & Co, Küsnacht | Process for determining the degree of purity of steel during the melting process or after tipping as a batch control |
| GB2176011A (en) * | 1985-05-10 | 1986-12-10 | Magyar Optikai Muevek | Method of and system for investigating thermal transformation |
-
1987
- 1987-04-24 DE DE3790942A patent/DE3790942C2/de not_active Expired - Fee Related
- 1987-04-24 WO PCT/SU1987/000049 patent/WO1988008531A1/en not_active Ceased
- 1987-04-24 DE DE873790942T patent/DE3790942T1/en active Pending
- 1987-04-24 JP JP62504972A patent/JPH01503085A/en active Pending
-
1988
- 1988-12-20 GB GB8829634A patent/GB2213355B/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2059852A5 (en) * | 1970-06-29 | 1971-06-04 | Qualitats Edelstahl Komb | Indirect determination of major components of fused alloy |
| DE2403146C3 (en) * | 1973-02-01 | 1981-10-15 | Dr. K. Ableidiger & Co, Küsnacht | Process for determining the degree of purity of steel during the melting process or after tipping as a batch control |
| GB2176011A (en) * | 1985-05-10 | 1986-12-10 | Magyar Optikai Muevek | Method of and system for investigating thermal transformation |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2790090A1 (en) * | 1999-02-24 | 2000-08-25 | Metal Science Ltd | Determination of magnesium content in a molten aluminum-silicon alloy involves thermal analysis of the molten alloy to which phosphorus and/or sulfur has been added, to derive eutectic temperature |
| BE1014517A3 (en) * | 1999-02-24 | 2003-12-02 | Metal Science Ltd | METHOD FOR DETERMINING THE MAGNESIUM CONTENT IN MOLTEN ALUMINUM ALLOYS. |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8829634D0 (en) | 1989-03-08 |
| JPH01503085A (en) | 1989-10-19 |
| GB2213355B (en) | 1991-04-17 |
| WO1988008531A1 (en) | 1988-11-03 |
| DE3790942C2 (en) | 1991-05-16 |
| DE3790942T1 (en) | 1989-05-03 |
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