DE10346781A1 - Iron melt quality measurement comprises use of surface tension measurement to assess impurity concentration and graphite precipitation - Google Patents
Iron melt quality measurement comprises use of surface tension measurement to assess impurity concentration and graphite precipitation Download PDFInfo
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- DE10346781A1 DE10346781A1 DE10346781A DE10346781A DE10346781A1 DE 10346781 A1 DE10346781 A1 DE 10346781A1 DE 10346781 A DE10346781 A DE 10346781A DE 10346781 A DE10346781 A DE 10346781A DE 10346781 A1 DE10346781 A1 DE 10346781A1
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- Prior art keywords
- surface tension
- melt
- quality
- iron melt
- assess
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 13
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 12
- 239000010439 graphite Substances 0.000 title claims abstract description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 10
- 238000001556 precipitation Methods 0.000 title claims abstract description 6
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 5
- 238000005259 measurement Methods 0.000 title abstract description 11
- 239000012535 impurity Substances 0.000 title 1
- 238000000034 method Methods 0.000 claims abstract description 20
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 18
- 239000011777 magnesium Substances 0.000 claims abstract description 18
- 239000000155 melt Substances 0.000 claims description 27
- 238000004458 analytical method Methods 0.000 claims description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 5
- 229910052717 sulfur Inorganic materials 0.000 description 5
- 239000011593 sulfur Substances 0.000 description 5
- 229910001018 Cast iron Inorganic materials 0.000 description 4
- 238000011088 calibration curve Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910001060 Gray iron Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000029142 excretion Effects 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 238000003869 coulometry Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000002076 thermal analysis method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
- G01N13/02—Investigating surface tension of liquids
-
- 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
- G01N33/205—Metals in liquid state, e.g. molten metals
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
- G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material
- G01N11/16—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material by measuring damping effect upon oscillatory body
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
- G01N9/24—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by observing the transmission of wave or particle radiation through the material
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Qualitätsbestimmung einer Schmelze gemäß dem Oberbegriff des Patentanspruchs 1.The The invention relates to a method for determining the quality of a melt according to the generic term of claim 1
Zur Qualitätsbestimmung von Schmelzen, insbesondere Gusseisenschmelzen, existieren bereits eine Anzahl von Verfahren, welche die Qualitätsbestimmung auf unterschiedlichen Wegen und anhand verschiedener Parameter der Schmelze durchführen. Beispielhaft seien genannt: Thermische Analyse, EMK-Messung, Coulometrie und diverse spektrometrische Verfahren.to quality determination of melts, in particular cast iron melts, already exist a number of methods which determine the quality at different Because of and based on various parameters of the melt perform. exemplary may be mentioned: thermal analysis, EMF measurement, coulometry and various spectrometric methods.
Die Aufgabe der vorliegenden Erfindung besteht darin, ein neues Verfahren zur Qualitätsbestimmung einer Schmelze anzugeben, welches schnell und einfach anwendbar ist.The The object of the present invention is a new process for quality determination To specify a melt, which is fast and easy to use is.
Diese Aufgabe wird von einem Verfahren mit den Merkmalen des Oberbegriffs von Patentanspruch 1 durch dessen kennzeichnende Merkmale gelöst. Vorteilhafte Ausgestaltungen sind in den Unteransprüchen angegeben.These Task is by a method with the characteristics of the preamble of claim 1 solved by its characterizing features. advantageous Embodiments are specified in the subclaims.
Gemäß der Erfindung wird zur Qualitätsbestimmung der Schmelze, ihre Oberflächenspannung bestimmt und mit einer vorbestimmten Eichkurve verglichen. Die Oberflächenspannung der Schmelze ist nämlich (bei einer definierten Temperatur) ein charakteristisches Maß für ihre Konzentration an einem charakteristischen Bestandteil (solange andere Bestandteile nicht variiert werden).According to the invention becomes quality determination the melt, determines their surface tension and compared with a predetermined calibration curve. The surface tension the melt is in fact (at a defined temperature) a characteristic measure of their concentration on a characteristic ingredient (as long as other ingredients can not be varied).
Gemäß einer vorteilhaften Ausgestaltung der Erfindung erfolgt die Qualitätsbestimmung durch Bestimmung der Oberflächenspannung bei verschiedenen Temperaturen der Schmelze und durch Vergleich der Ergebnisse mit einem vorbestimmten Eichfeld. Dadurch wird die Genauigkeit erhöht.According to one advantageous embodiment of the invention, the quality is determined by determining the surface tension at different temperatures of the melt and by comparing the Results with a predetermined gauge field. This will increase the accuracy elevated.
Die Bestimmung der Oberflächenspannung erfolgt mit bekannten Methoden, z.B. nach der Methode der hängenden oder liegenden Tropfen (Kontaktwinkelmessung) oder mittels Tropfenschwingungsanalyse. Letztere kann anhand freifallender oder elektromagnetisch levitierter Tropfen erfolgen. Zur Messung muss jeweils eine Schmelzeprobe entnommen werden. Dies erfolgt mittels messneutraler keramischer Probennehmer. Für besondere Genauigkeitsanforderungen erfolgen Probennahme und Messung unter Schutzgasatmosphäre, vorzugsweise Argon, um Messfehler infolge Oxidation der Schmelze zu vermeiden.The Determination of the surface tension takes place by known methods, e.g. according to the method of hanging or lying drops (contact angle measurement) or by means of droplet vibration analysis. The latter can be determined by free-falling or electromagnetically levitated Drops are made. For measurement, a melt sample must be taken become. This is done by means of messneutral ceramic sampler. For special Accuracy requirements are made sampling and measurement below Protective gas atmosphere, preferably argon, to measurement errors due to oxidation of the melt to avoid.
Besonders vorteilhaft ist es, das erfindungsgemäße Verfahren zur Qualitätsbestimmung einer Eisenschmelze anzuwenden, da derartige Schmelzen in besonders großen Mengen industriell verarbeitet werden.Especially it is advantageous, the method of the invention for quality determination to apply an iron melt, since such melts in particular huge Quantities are processed industrially.
Entscheidend für die Qualität einer Eisenschmelze ist die Ausscheidungsform des in ihr enthaltenen Graphits. Diese kann von lamellar, über vermikular bis globular reichen und ist ein charakteristisches Maß für die Festigkeit bzw. Zerspanbarkeit des aus der Schmelze erstarrten Graugusses.critical for the quality an iron melt is the excretory form of the contained in it Graphite. This can be from lamellar, vermiculous to globular range and is a characteristic measure of the strength or machinability of the melt solidified gray cast iron.
Entscheidend für die sich ausbildende Ausscheidungsform des Graphits ist der Anteil grenzflächenaktiver Bestandteile an der Zusammensetzung der Schmelze, insbesondere der Anteil von Sauerstoff und Schwefel. Letztere lagern sich bevorzugt auf der Prismenfläche der Graphitkristallgitter an und erhöhen somit deren Wachstumsgeschwindigkeit in dieser Richtung, woraus eine lamellenförmige Graphitausscheidung resultiert. Um dies zu verhindern bzw. zu verringern, werden der Schmelze Elemente zugefügt, die gegenüber Sauerstoff und Schwefel eine höhere chemische Affinität aufweisen als Graphit oder Kohlenstoff und daher die Schmelze Entschwefeln und desoxidieren. Geeignete Elemente sind die Erdalkalimetalle, insbesondere Magnesium und Cer. Aus Kostengründen werden meist Magnesium oder Magnesiumlegierungen verwendet.critical for the Forming precipitate of graphite is the fraction of surface active Ingredients in the composition of the melt, in particular the Proportion of oxygen and sulfur. The latter preferably accumulate on the prism surface the graphite crystal lattice and thus increase their growth rate in this direction, resulting in a lamellar graphite precipitation. To prevent or reduce this, elements are added to the melt which across from Oxygen and sulfur higher chemical affinity have as graphite or carbon and therefore the melt desulfurization and deoxidize. Suitable elements are the alkaline earth metals, especially magnesium and cerium. For cost reasons, mostly magnesium or magnesium alloys used.
Nachfolgend
wird das erfindungsgemäße Verfahren
anhand von zwei Ausführungsbeispielen und
der
In
einem ersten Ausführungsbeispiel
wird die Qualität
einer gängigen
Gusseisenschmelze bestimmt.
Der Magnesiumgehalt wird durch Messung der Oberflächenspannung wie folgt bestimmt: Zunächst wird empirisch eine Eichkurve ermittelt. Dazu wird einer Schmelze mit gegebener Temperatur und Zusammensetzung in definierten Schritten Anteile an Magnesium zugegeben und jeweils die Oberflächenspannung bestimmt, indem an liegenden Schmelzetropfen die Kontaktwinkel gemessen werden und daraus die Oberflächenspannung (mittels automatischer Verfahren) berechnet wird. Üblicherweise werden mehrere Proben gemessen und Mittelwerte der Messergebnisse zur Berechnung der Oberflächenspannung verwendet. Man erhält so für die gegebene Temperatur und Zusammensetzung (ohne Berücksichtigung der veränderten Magnesiumanteile) der Schmelze eine Eichkurve der Oberflächenspannung in Abhängigkeit von der Magnesiumkonzentration. Analog geht man bei anderen Temperaturen vor und erweitert so die Eichkurve auf ein Eichfeld.The magnesium content is determined by measuring the surface tension as follows: First, a calibration curve is determined empirically. To is added to a melt with a given temperature and composition in defined steps proportions of magnesium and in each case the surface tension is determined by measuring the angle of contact lying on the molten droplets and from the surface tension (by automatic method) is calculated. Usually several samples are measured and mean values of the measurement results are used to calculate the surface tension. Thus, for the given temperature and composition (without taking into account the changed magnesium contents) of the melt, a calibration curve of the surface tension as a function of the magnesium concentration is obtained. Analogously, one proceeds at other temperatures and thus extends the calibration curve to a gauge field.
Mittels dieses Eichfeldes kann man nun die Qualität der Schmelze während üblicher Produktionsverfahren regelmäßig überprüfen, indem man lediglich den Kontaktwinkel von Schmelzetropfen misst und daraus die Oberflächenspannung bestimmt.through This calibration field can now be the quality of the melt during normal Check production processes regularly by one measures only the contact angle of melt drops and from it the surface tension certainly.
Genauere Ergebnisse erhält man, wenn man die Oberflächenspannung bei unterschiedlichen Temperaturen bestimmt und die daraus erhaltene Funktion mittels bekannter (linearer oder nicht-linearer) Optimierungsmethoden an das Eichfeld optimiert und über die beste Anpassung den optimalen, d.h. den mit dem geringsten Fehler behafteten Wert der Magnesiumkonzentration ermittelt.more accurate Results obtained one, considering the surface tension determined at different temperatures and the resulting function using known (linear or non-linear) optimization methods optimized to the gauge field and over the best fit the optimal, i. the one with the least error Affected value of magnesium concentration determined.
Die Oberflächenspannung kann anstatt über Kontaktwinkelmessung auch durch Schwingungsanalyse fallender oder schwebender Schmelzetropfen nach bekannten Verfahren erfolgen.The surface tension rather than via contact angle measurement also by vibration analysis falling or floating melt drops after take place known methods.
Das erfindungsgemäße Verfahren erweisen sich in den Ausführungsformen der vorstehend beschriebenen Beispiele als besonders geeignet für die schnelle und einfache Bestimmung der Qualität von Gusseisenschmelzen wie sie insbesondere in Gießereien der Automobilindustrie verwendet werden.The inventive method prove in the embodiments The examples described above are particularly suitable for the fast and easy determination of the quality of cast iron melts like especially in foundries used in the automotive industry.
Die Erfindung ist nicht nur auf die zuvor geschilderten Ausführungsbeispiele beschränkt, sondern vielmehr auf weitere übertragbar.The Invention is not limited to the previously described embodiments limited, but rather transferable to others.
So ist es auch möglich, anstatt der Berechnung der Oberflächenspannung aus den Kontaktwinkeln direkt den Kontaktwinkel als gleichwirkendes charakteristisches Maß des Magnesiumgehaltes und damit der Schmelzequalität zu verwenden.So it is also possible instead of calculating the surface tension from the contact angles directly the contact angle as the same effect characteristic Measure of Magnesium content and thus the melt quality to use.
So
weist die in
Dieselbe Schmelze weist bei einem Magnesiumgehalt von 0,06 Gewichtsprozent einen deutlich kleineren Kontaktwinkel auf. Bei 1120°C beträgt der Kontaktwinkel circa 133° und bei 1200°C circa 131°.the same Melt has at a magnesium content of 0.06 weight percent a much smaller contact angle. At 1120 ° C the contact angle is about 133 ° and at 1200 ° C about 131 °.
Beide Geraden besitzen also die gleiche Steigung aber in Abhängigkeit vom Magnesiumgehalt charakteristische Ordinaten, die somit als Qualitätsmaß der Schmelze gleichwirkend zur Oberflächenspannung herangezogen werden können.Both Straight lines therefore have the same slope but in dependence Ordinaten characteristic of the magnesium content, thus the quality measure of the melt same effect to the surface tension can be used.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10346781A DE10346781A1 (en) | 2003-10-08 | 2003-10-08 | Iron melt quality measurement comprises use of surface tension measurement to assess impurity concentration and graphite precipitation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10346781A DE10346781A1 (en) | 2003-10-08 | 2003-10-08 | Iron melt quality measurement comprises use of surface tension measurement to assess impurity concentration and graphite precipitation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE10346781A1 true DE10346781A1 (en) | 2005-05-25 |
Family
ID=34484715
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE10346781A Withdrawn DE10346781A1 (en) | 2003-10-08 | 2003-10-08 | Iron melt quality measurement comprises use of surface tension measurement to assess impurity concentration and graphite precipitation |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE10346781A1 (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2149228A1 (en) * | 1970-10-01 | 1972-04-06 | Fulmer Res Inst Ltd | Device and method for determining the surface tension of liquids |
| DE2709698A1 (en) * | 1977-03-05 | 1978-09-07 | Battelle Institut E V | Fluid density, surface tension and viscosity measurement - using ultrasonic suspension of drop at pressure node and adjusting transmitter compensation voltage |
| DE3441317A1 (en) * | 1984-11-12 | 1986-08-07 | Hahn, Axel, Dr., 1000 Berlin | Appliance for measuring interface tension |
| DE3808860A1 (en) * | 1988-03-17 | 1989-10-05 | Bayer Ag | Method for automatically measuring surface tension or interfacial tension in order to optimise physical processes at the interfaces |
| EP0694779B1 (en) * | 1994-07-08 | 1997-07-30 | Heraeus Electro-Nite International N.V. | Device for measuring surface tension |
| US5891213A (en) * | 1995-05-29 | 1999-04-06 | Sintercast Ab | On-line production control of cast irons by measuring the surface tension of the base treated iron |
-
2003
- 2003-10-08 DE DE10346781A patent/DE10346781A1/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2149228A1 (en) * | 1970-10-01 | 1972-04-06 | Fulmer Res Inst Ltd | Device and method for determining the surface tension of liquids |
| DE2709698A1 (en) * | 1977-03-05 | 1978-09-07 | Battelle Institut E V | Fluid density, surface tension and viscosity measurement - using ultrasonic suspension of drop at pressure node and adjusting transmitter compensation voltage |
| DE3441317A1 (en) * | 1984-11-12 | 1986-08-07 | Hahn, Axel, Dr., 1000 Berlin | Appliance for measuring interface tension |
| DE3808860A1 (en) * | 1988-03-17 | 1989-10-05 | Bayer Ag | Method for automatically measuring surface tension or interfacial tension in order to optimise physical processes at the interfaces |
| EP0694779B1 (en) * | 1994-07-08 | 1997-07-30 | Heraeus Electro-Nite International N.V. | Device for measuring surface tension |
| US5891213A (en) * | 1995-05-29 | 1999-04-06 | Sintercast Ab | On-line production control of cast irons by measuring the surface tension of the base treated iron |
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| OP8 | Request for examination as to paragraph 44 patent law | ||
| 8130 | Withdrawal |