Sensor indicator for measurement of oxygen content in cast-iron melt

UKRAINE

(19) and A (11) 94792 (13) C2

(51) IPC

Ο01Ν 27/411 (2006.01) C21S 1/04 (2006.01)

MINISTRY OF EDUCATION SCIENCE OF UKRAINE

STATE DEPARTMENT OF INTELLECTUAL PROPERTY

DESCRIPTION

TO THE INVENTORY PATENT

(54) SENSORY SENSOR FOR MEASUREMENT OF OXYGEN CONTENT IN CHAIN ​​MASSAGE

(21) a200908688

(22) Jan 14, 2008

(24) Jun 10, 2011

(86) PCT / ЕР2008 / 000226, 14.01.2008

(31) 10 2007 004 147.2

(32) Jan 22, 2007

(33) ΕΕ

(46) 10.06.2011, bulletin No. 11, 2011

(72) HABETS DANNY, BE

(73) HERAUS ELECTRONIC-NAYT INTERNATIONAL NV, ΒΕ

(56) and А 75693 С2, 15.05.2006

1173863 A, July 10, 1989

No. 4135510 A1, 29.04.1993

57149956 A, September 16, 1982

υδ 4657641 A, 14.04.1987

(57) 1. Sensor sensor for measuring the content of oxygen in a cast iron melt using an electrochemical measuring element containing a solid electrolyte tube, characterized by the fact that the tube is made of zirconium dioxide, as well as the fact that the outside of the surface of the tin

The invention relates to a method of influencing the power of pig iron by adding magnesium to a cast-iron melt. The invention also relates to a sensing sensor for measuring the oxygen content of a precipitated melt using an electrochemical measuring element having a tube from a solid electrolyte.

Typically, the content of free magnesium in the ironmilk is regarded as a determining factor for the formation of spheroidal or worm-graphite in iron-treated magnesium. Modern practice of regulating the production of malleable iron lies in determining the total content of magnesium, i.e. free and conjugated magnesium, by means of spectral examination of samples. However, such a method does not give a complete picture, since the content of free magnesium is not known, and the measurement does not give information about the activity of oxygen. However, the activity of oxygen, which is in equilibrium with free magnesium, is a determining factor in the formation

Baki from a solid electrolyte coating is covered with zirconium oxide.

2. Sensor sensor according to claim 1, characterized in that zirconium dioxide is stabilized with calcium oxide, yttrium oxide and / or magnesium oxide.

3. Sensor sensor according to claim 2, characterized in that the coating is stabilized with calcium oxide in the amount up to 30obs. %, magnesium oxide in an amount up to 25ob. % and / or yttrium oxide in amounts up to 52ob. %

4. Sensor sensor according to claim 3, characterized in that the coating is stabilized with calcium oxide in the amount of about 4-6 atmospheres. %

5. Sensor sensor according to claims 1 to 4, characterized by the fact that the coating is applied by the plasma sputtering method.

6. Sensor sensor according to any one of claims 1 to 5, characterized in that the coating has a thickness of about 30-50 μm, in particular about 40 μm.

7. Sensor sensor according to claim 1, characterized in that the tube of zirconium dioxide is stabilized by magnesium oxide in the amount of 2об. %

graphite form. The so-called malleable cast iron is Normal gray gray iron, which is processed by the additive that forms the ball, so that the main part of graphite carbon in the cast iron is the so-called "knot-watt" graphite or gypsum graphite. "Nose-wadding" graphite in cast iron must analyze the form of the shape, size and number of particles, since these indicators have an influence on the mechanical properties of cast iron. The visual analysis is constructive or subjective, even with partially automated analysis. Similar measurements are known, for example, from 5675097. In Yue199 28 456 A1, the measurements are not described in order to determine the spatial structure of graphite in cast iron, which are based on the determination of oxygen content and have no drawbacks of visual methods. This enables faster response,

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casting magnesium can be provided, for example, by means of a metallographic or spectrographic analysis of samples at the stage of "white foaming" or also by thermal analysis

In general, pure magnesium or magnesium alloy sufficient to promote the formation of a spherical form of the waves. One part of the added magnesium removes from the outside of oxygen and sulfur, and the other part is the so-called free fraction of magnesium, which regulates the activity of oxygen. The content of free magnesium in the melt is a determining factor for the "knotty" of cast iron 3 cha-som content of free magnesium in the melt decreases, while the activity of oxygen increases. This affects the structure and mechanical properties of pig iron.

Sensor sensors for the determination of the activity ofoxygen in a metallic melt are known, for example, from 103 103 387 B3. Here is a tube of solid electrolyte, the outer surface of which is coated with a mixture of calcium zirconate and fluoride, which, for example, in the melt of iron, can measure the concentration of sulfur, silicon or carbon

It is an object of the present invention to provide a method and a sensor sensor for regulating a method that would improve the prior art, and that the mechanical properties of the actuator could be purposefully influenced by the step of the liquid phase

The problem is solved by means of the features of the non-exemplary claims of the invention. Exemplary embodiments are set forth in the dependent claims of the formula. In particular, the method according to the invention is different in that the oxygen content is measured in a pig iron spillway and that the magnesium is added to the iron melt until the oxygen content in the casting melt the temperature of about 1420 ° C (as the reference temperature) will not be from 0.005 to 0.2 hours-a-million. Since the measurement of oxygen is more accurate than the possible measurement of magnesium (magnesium in the melt is present as in the fork it form and shape in the United makes nemozhlyvymtochnyy account) the determination of the mechanical properties of the cast iron is also more precise. The specialist can identify and use the correlation between the presence of a smaller number of larger graphite particles with a low content of oxygen on the one hand and more than the number of smaller graphite particles with higher oxygen content on the other side. Thus, a correlation with mechanical properties, as already was is described in 5 675 097, for example, resistance to breaking, elongation and resistance to deformation. Unexpectedly for iron, it has been established that it has a maximum elongation, when avannya magnesium continues until kysnyune content will be less than 0.1 ppm, kraschevid 0.08 to 0.1 million at more or menshomuvmisti oxygen elongation iron again zmenshuyet Xia. It is advisable to add about 200-750 parts per million of magnesium to the iron melt to provide the desired oxygen content.

Sensor sensor according to the invention

It is driven by the direction of the outside surface

Tubes made of solid electrolyte coating

from zirconium dioxide. In particular, zirconia is in

the coating can be stabilized by calcium oxide

This, yttrium oxide and / or magnesium oxide. It is advantageous when the coating is stabilized with calcium oxide in a quantity of up to 30% by volume, with magnesium oxide up to 25% by volume and / or by yttrium oxide up to 52% by volume. It is particularly advantageous for the coating to be stabilized with no calcium oxide in the amount of about 4 -6ab%. It is advisable to apply a coating on the sensor sensormethod of plasma spraying. It is best if it has a thickness of about 30-50 μm, in particular 40 μm. It is advisable that the tube from the solid electrolyte, which is the coating, is a tube of zirconium dioxide, which can be stabilized by magnesium oxide in an amount of about 2ob.%.

Below, with reference to the drawings, an exemplary embodiment of the invention is described. They depict:

1 - Interconnection between the number of graphiteparticles and oxygen content (oxygen activity aO);

Figure 2 - The relationship between relative elongation and oxygen content,

Fig. 3 - Cross section of the sensor head and

FIG. 4 is another form of sensor datatype execution. FIG.

In Fig. 1 it is seen that the number of graphite particles grows with increasing content of oxygen (activity of oxygen aO). Consequently, by adjusting the content of the oxygen by adding magnesium it is possible to introduce the number of graphite particles. In this way, the purposeful influence of the casting property is already in the melt. The maximum "bruising" occurs with oxygen activity from 0.10 to 0.12 parts per million (essentially for 1420 ° C) .If the oxygen activity falls below 0.10 parts per million, "biting" decreases. This tells the well-known experience in the practice of foundryproduction, that too high a share of magnesium negatively affects the "knotty".

2 shows the relationship between the relative length of cast iron and the oxygen content. Maximum extension (elongation) is recorded somewhere at 0.08 parts per million. At lower activity, the oxygen elongation becomes slightly less, possibly due to less "nodularity". When the oxygen activity passes to the optimum value, there is a gradual decrease in elongation. The graph shows that this can be achieved by setting the oxygen content in the iron melt by adding magnesium to the effect on the expansion of the cast iron.

3 is a sensor sensor according to the invention. In the metal tube 1 in the filler of 3 pieces of sand, there are electrical wires 2 (Οιι / ΟιιΝί-wires). Through the connecting part, 4 electro-wires are connected with an oxygen spear or with another holder, and then with a node for processing data. The other end of the wires 2 is connected to the thermoelectric cell 5 and to the electrochemical measuring element 6. The electrochemical element 6 is a tube of solid electrode (element ZZO2) with a shockproof steel screen as an outer shell. Element ΖγΟ2 on its outer surface has a coating of zirconia, stabilized with calcium oxide in an amount of 5 vol%. This coating has a thickness of about 40 microns. On the drawing it is not depicted in detail, since the pipes from the solid electrolyte are in principle known.

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The thermocouple 5 is fixed with a sealing cement 7. The measuring element 6 is also fixed with cement 8, and it is located in the middle of the sensor sensor, the end is closed by a sealing cork 9, through which the electrical contacts are removed. Both sensor sensors 5, 6 are connected between themselves with the help of a plastic clamp

10. Through the thermally insulating part 11, the wires are protruded inside the metal tube 1. At the immersion end of the sensor sensor, the sand body 12 is located on the outer side of the metal pipe 1 in order to protect it.

FIG. 1 shows a similar structure where contact sensor contact is shown in the tubular stomach carrier 13. The tubular carrier 13 is made of cardboard and is surrounded by a spray 14 made from a molding mixture or a cementitious one on its front side, the reverse of the doping body 12. . The sensing elements 5, 6 themselves for protecting the transport and immersion in the melt in the first place are in the metal cap 15, which, when immersed in the sensor into a metallic melt, dissolves and releases the sensor elements 5, 6.

Number of graphite particles

AO at 1420 ° C (mln^-1)

FIG 1

Interconnection between oxygen content and relative elongation of cast iron

FIG 2

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FIG with

Computer layout N. Lysenko Signature Circulation 24 copies.

Ministry of Education and Science of Ukraine

State Department of Intellectual Property, st. Uritskogo, 45, Kyiv, SME, 03680, Ukraine

State Enterprise "Ukrainian Institute of Industrial Property", st. Glazunova, 1, Kyiv - 42, 01601