The name of the invention: nozzle structure
Technical field
[0001]
　The present invention relates to a nozzle structure for molten steel discharge.
Background technique
[0002]
　For example from a tundish for discharging the molten steel, the nozzle structure as the molten steel discharge path from the molten steel inlet to the mold, it is composed of a refractory member which is divided into a plurality of the molten steel discharge direction (vertical direction) there is. This is for performing dynamic flow control function in the molten steel discharge part of the nozzle structure, or to optimize the balance of durability for different damage etc. for each region of the molten steel discharge path, or partial exchange in order to enable.
[0003]
　Such a plurality of refractory members combined nozzle structure will inevitably be joints exist between the refractory member. In these joints, because with respect to the portion with the sliding of such sliding nozzle can not be used joint fillers or sealing material becomes a contact structure in the so-called empty joints, installing a mortar or sealant may in part there are no other sliding often. However, these joints, a lesser degree due to the presence or absence of such joint fillers, easy to draw the outside air into the inner bore of the nozzle structure (see FIG. 13). When retracted outside air is adhesion of alumina inclusion, etc. to the bore or obstruction, increased oxide and lead to degradation or the like of other steels.
[0004]
　As a countermeasure against this outside air retraction, for example, as shown in FIG. 14, performs flow control function with a stopper 7 which is placed on top instead of the nozzle, the nozzle portion structure is employed that an integral immersion nozzle without a joint Sometimes. However, in the continuous casting of steel will tend to extend the long casting time by the multi-continuous casting, etc., to replace part of the nozzle, such as immersion nozzle, which consists of a plurality of divided refractory member structure even may still be required, so that the joints are still present in this case.
[0005]
　As a countermeasure against the outside air draw on this joint portion, Patent Document 1, "the gap formed between the outer periphery arranged case casting nozzle refractories and the refractory material, the outer circumference or the inner of the refractory the metal pipe is disposed so as to cover at least a portion of the circumference, a plurality of gas blow holes or slits in the metal pipe, by introducing a gas from at least one end of the metal pipe, the surrounding vicinity of the refractory to the gas seal casting nozzle, characterized in that. "is disclosed.
CITATION
Patent Document
[0006]
Patent Document 1: Laid-Open Patent Publication No. 11-104814
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　The Patent Document 1, since the gas seal by introducing a gas (inert gas), can be the risk of pulling the particularly harmful oxygen to the ambient air i.e. the molten steel decreases, gas (inert gas) draws still . Although the case has been drawn a gas (inert gas) problems associated with the oxidation of the molten steel and the refractory is reduced, the risk of lead to quality defects such as pinholes in the steel remains.
[0008]
　An object of the present invention is to provide, in a nozzle structure for molten steel discharge the joint portion is composed of a plurality of refractory members are present, it is to improve the sealing property.
Means for Solving the Problems
[0009]
　The present invention provides a nozzle structure for the next 1-7.
1. The joint portion to be joined by dividing the molten steel discharge path in a vertical direction to a nozzle structure for molten steel discharge provided in one or more places, in the inner hole surface of the nozzle structure, the inner bore sleeve of refractory There is disposed so as to straddle at least one of the vertical direction of the joint portion, the nozzle structure.
2. Said bore sleeve is installed in the bore surface through the adhesive, the nozzle structure according to the 1.
3. The upper end of the inner hole side of the bore sleeve is a curved surface or inclined surfaces, the nozzle structure according to the 1 or 2.
4. The outer periphery of the bore sleeve a horizontal position corresponding to the one or more joints, one or more set up a non-continuous recess or continuous groove, the nozzle structure according to any one of the 1 of the 3 body.
5. The one or more discontinuous recess or continuous groove, relatively more placed on either or both surfaces of the front and rear pressing direction for the sliding direction or dismantling removed below the nozzle from the joints the nozzle structure according to the 4.
6. Refractory high-adhere than refractory of the nozzle structure body, a nozzle structure according to any one of the 1 of the 5 forming the bore sleeve.
7. The bore sleeve, the CaO component about 15 wt% or more, containing MgO to the remainder, CaO / MgO weight ratio consists refractory of 0.1 to 1.5, the nozzle structure according to the above 6 .
Effect of the invention
[0010]
　According to the present invention, the inner hole surface of the nozzle structure, it was established the inner bore sleeve so as to cross at least one of the vertical joints, the sealing of the nozzle structure is improved. Then, all the joints above and below when installing the inner bore sleeve so as to straddle the direction, it is possible to obtain the nozzle about the same sealing of integral structure without joints.
[0011]
　Further, by providing the recess or groove on the outer periphery of the bore sleeve, also, safely without prejudice sealing properties when such removal is folded at a particular location of the nozzle structure, also separated accurately at a given site it is possible to, even when installing a subsequent replacement, while maintaining high precision such as unevenness is small junction at the bonding surface, and easily can remove or install work.
[0012]
　Furthermore, characteristic for adhesion of damage or alumina inclusion of the bore surface is different, it is possible to selectively apply refractory comprise various materials, physical properties freely and easily. Hence, it is possible to suppress the deterioration in the quality of the steel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
[1] In an image diagram of an example of a nozzle structure of the present invention, (a) shows the example constructed above the nozzle, the upper plate, the middle plate, the bottom plate, the bottom nozzle and the immersion nozzle, (b) the upper nozzle and the immersion an example composed of a nozzle.
In the nozzle structure [2] The present invention is an image diagram showing an example in which the joint portion does not match the joints and the inner bore sleeve to be joined by dividing the molten steel discharge path in the vertical direction.
[Figure 3] notched inner bore surface upper end portion of the nozzle (refractory member) to be installed relatively downward, i.e. toward the inner bore-side is an image diagram showing an example having an inclined or curved downwardly.
[4] In image diagram illustrating an example of the bore sleeve of the present invention, (a) is a top view, (b) is a longitudinal sectional view.
5 is a conceptual diagram of a vertical section showing an example in which a curved or inclined face an upper end of the inner bore sleeve (inner hole side) of the present invention.
In the nozzle structure [6] The present invention, an inner bore surface of the nozzle structure, the inner bore surface of the bore sleeve placed on the inner side is an image diagram showing an example which is flush.
In the nozzle structure [7] The present invention, an inner bore surface of the nozzle structure, the inner bore surface of the bore sleeve installed inside thereof is an image diagram showing an example which is flush only the lower end.
8 is an image diagram of a longitudinal section of a recess or groove in a portion of the outer periphery of the inner bore sleeve showing an example in which in one or a division of the present invention.
[9] divides the recess into a portion of the periphery of FIG. 8 shows an example in which the positions 4 is an image diagram of the A-A cross section in FIG.
[Figure 10] shows an example in which one a groove continuous in the circumferential direction on a part of the periphery of FIG. 8 is a conceptual view of A-A section of FIG.
In the nozzle structure [11] FIG. 1 (a), when removing folding the inner bore sleeve immersion nozzle at the position of the junction surface of the upper end, or the region of the bore sleeve from the molten steel inlet to the immersion nozzle upper end surface is an image view of when installed in.
Is an image view when FIG. 12 was installed further immersion nozzle after removal of the immersion nozzle in the manner of FIG.
Shown [13] over the conventional nozzle, sliding nozzle plate three-element, which is constructed from the bottom nozzle and the immersion nozzle, and an example of a nozzle structure with a joint portion, an image of the case to draw external air from joints it is a diagram.
14 is a conceptual diagram showing an example of a nozzle of a unitary structure with no joints (immersion nozzle).
DESCRIPTION OF THE INVENTION
[0014]
　Typically and division number that is, the number of joints is most often the form of nozzle structure of the present invention, the upper nozzle, sliding nozzle plates three configurations (top plate, the middle plate, a lower plate), the intermediate nozzle, lower nozzle, submerged nozzle a case composed of a plurality of refractory members like. However, not necessarily limited to this embodiment, it may be any form by any two or more combinations of the respective refractory. For example, FIG. 1 (a), the upper nozzle 1, the upper plate 2a, an example configured middle plate 2b, the lower plate 2c, from below the nozzle 3 and the immersion nozzle 4, FIG. 1 (b), the upper nozzle 1 and the immersion an example composed of nozzles 4. That is, the nozzle structure of the present invention is a nozzle structure for molten steel discharge to a joint portion for joining by dividing the molten steel discharge path having an inner bore 5 in the vertical direction with the one or more locations. Then, the nozzle structure of the present invention, the inner hole surface of the nozzle structure, the inner bore sleeve 6 made of refractory is disposed so as to straddle at least one of the vertical direction of the joint portion.
[0015]
　The inner bore sleeve 6, the sealing property more reliably, in order to further enhance, as shown in FIG. 1 (a) and 1 (b), an integral structure without dividing in the vertical direction, all it is most preferred to install the joint portion so as to straddle the vertical direction. However, the bore sleeve, if placed astride on at least one of the vertical joints, which contributes to the improvement of the sealing property.
[0016]
　Furthermore, bore sleeve 6, it is also possible to divide into a plurality in the vertical direction as shown in FIG. 2, when such a division structure, the division portion or joint portion A1, the nozzle structure it is necessary not to coincide with the dividing portion or joint portions B1, B2 of the molten steel discharge path is the body itself. In other words, the straddle an inner hole sleeve joints in the vertical direction in the present invention, in the vertical direction of the horizontal position of the bore sleeve corresponding to the joint portion in the continuous body bore sleeve is not divided in the vertical direction It means that there. In order to effectively suppress the retraction of the outside air (gas) from the nozzle structure outside, vertical spacing between the joint portions B1, B2 of the joint part A1 and the nozzle structure body bore sleeve 6 ( length) L is the experience, is preferably at least the thickness of the inner bore sleeve 6.
[0017]
　Also, when installing the inner bore sleeve, horizontal positions of the nozzles constituting the nozzle structure (refractory member) is required to be present exactly in place. Relative horizontal position of each nozzle is determined by the set device, for example, as shown in FIG. 3, the inner bore surface upper end portion of the nozzle installed in a relatively downward, the upper nozzle it is preferable that the lack horizontal relative accuracy over long off the lower nozzle, i.e. towards the inner bore-side preferably provided a portion having a sloped or curved downward. This makes it possible to set up smoothly when charged bore sleeve from above into the inner bore of the nozzle structure.
[0018]
　The shape of the bore sleeve 6 is typically as shown in FIG. 4 is a cylindrical, upper portion of the inner bore-side thereof, a curved or inclined surface, as shown in FIG. 5, the molten steel as much as possible the discharge it is preferable that the small angle or gradually increasing shape with respect to the direction. When the stepped structure having a large angle such as, for example horizontal plane relative to the discharge direction of the molten steel, the molten steel flow is greatly disturbed at that portion, adhesion of inclusions is a risk of lead to localized damage to the inner bore sleeve is there.
[0019]
　The inner bore surface 6a of the bore sleeve 6, can be in the inner bore surface 5a and flush nozzle structure as shown in FIG. Thus it is possible to eliminate the step portion of the inner bore surface of the upper and lower ends of the bore sleeve 6.
[0020]
　It is also possible to eliminate the stepped portion of the bore surface only at the lower portion of the inner bore sleeve 6 as shown in FIG. The stepped portion at the lower end portion also may become a base point causing disturbance of the molten steel flow of the vortex flow such that part. Thus alone eliminate the stepped portion of the bore surface only at the lower portion of the inner hole sleeve 6 in the case where, possible to prevent the disturbance of the molten steel flow is generated. Also, by the same diameter lower end of the bore sleeve 6 and the inner bore surface 5a of the nozzle structure (flush), it is also possible to prevent falling or displacement downward of the bore sleeve 6. In order to prevent falling or deviation downward bore sleeve 6, the inner hole surface 5a of the nozzle structure in the vicinity immediately below the lower end of the bore sleeve 6 may be provided with a projecting portion and the inclined portion.
[0021]
　The outer periphery of the bore sleeve 6 can be provided one or more non-contiguous recesses 6b or continuous groove 6c as shown in FIG. For example, provided in four places by dividing the recess 6b in a part of the outer periphery of the bore sleeve 6 in the example of FIG. 9, the groove portion continuous in the circumferential direction on a part of the outer periphery of the bore sleeve 6 in the example of FIG. 10 It is provided one of the 6c. These recesses 6b or groove portion 6c is provided on the outer circumference of the inner bore sleeve 6 in the horizontal position corresponding to the joint portion of the nozzle structure body. The reason for this is as follows. First, for such exchanging a portion of the refractory member in an emergency or nozzle structure (components), when removing the immersion nozzle 4 as shown in FIG. 11, for example at the position of the joint surface of the upper end, the bore sleeve 6 there is a possibility that the inner bore sleeve 6 and is located inside disrupt a complex form in an irregular position, also it may become difficult to destruction itself. Therefore, the horizontal position the outer circumference in the recess 6b or groove portion 6c of the inner hole sleeve 6 (horizontal position corresponding to the upper end portion of the immersion nozzle 4 in the case of FIG. 11) corresponding to the joint portion of the nozzle structure body as described above by providing, to easily destroy the bore sleeve 6, further it can be broken with high accuracy from a predetermined position desired (see Figure 12).
[0022]
　In the case of stopping the molten steel flow by closing the nozzle in a location other than the stopper caused the abnormal to the stopper control the "emergency", for example, a portion of the nozzle structure They become slidable, the slide when separating such folding an inner hole sleeve at the slide portion and the like by. Also, the the "replacing a portion of the refractory member of the nozzle structure (parts)", for example an immersion nozzle, sliding horizontally, or obliquely downward bore sleeve by adding mechanical load Remove the immersion nozzle to break, then again by sliding the other of the immersion nozzle in the horizontal direction, or the like when mounting from below. In any of these cases, the bore sleeve are preferably destroyed easily and irregularities less accurate.
[0023]
　These recesses 6b or groove portion 6c is that relatively many placed on either or both surfaces of the front and rear pressing direction for the sliding direction or dismantling removed below the nozzle from the joint portion of the nozzle structure body It is preferred. The outer periphery of the sliding direction or pressure direction because become the origin of stress.
[0024]
　Further, it is preferable that the inner bore sleeve 6 which is installed in the inner hole surface of the nozzle arrangement via an adhesive such as mortar. Risk of draw gas by installing a bore sleeve 6 reduces, but if you do not use an adhesive becomes necessary to devise such enhanced surface accuracy of the bonding surface to the extent that gas does not pass. This is not realistic also from the viewpoint of cost.
[0025]
　Adhesive (mortar), depending on the composition of the nozzle structure, they material does not cause melting or the like, etc., generally as long as the material used for the nozzle structure can be used without particular limitations. In the knowledge on the experience of the inventors, for example, apparent porosity, if the mortar extent approximately 30% or less after heat treatment on the order of about 1000 ° C. ~ 1400 ° C., gas or the like to pass through to the inner bore it is not.
[0026]
　On the other hand, non-metallic inclusions and bullion adhesion of or growth of alumina or the like in the inner bore surface of the bore sleeve 6, in the operation surface of the disturbance or the like casting speed decrease of the molten steel flow during casting, steel quality and production adversely affect the sex. Further dismantling or removal of the nozzle including the immersion nozzle becomes difficult. Accordingly, refractories forming the inner bore sleeve 6 by the material is high-adhere than refractory of the nozzle structure body, it is possible to reduce the adhesion of alumina inclusions to the inner bore surface further it can reduce the adhesion or growth of bullion. The material high flame adhesion, for example, CaO ingredient about 15 weight percent or more, the balance MgO, ZrO to 2 wherein the refractory components such as carbon, CaO / MgO weight ratio is 0.1 to 1.5 refractory, mention may be made of other molten or molten steel reacts with components containing the chemical composition to smooth the surface-adjusted material, or material, etc. with enhanced surface smoothness.
[0027]
　In the above embodiment has described the nozzle structure for discharging the molten steel from the tundish into the mold as an example, the scope of the present invention is not limited for tundish, other nozzle for molten steel discharge It can also be applied to the structure.
DESCRIPTION OF SYMBOLS
[0028]
　1 upper nozzle
　2a on the plate
　2b in the plate
　2c lower plate
　3 lower nozzle
　4 submerged nozzle
　5 in the hole
　5a bore surface
　6 hole sleeve
　within 6a bore surface
　6b recess
　6c groove
　7 Stopper
The scope of the claims
[Claim 1]
　The joint portion to be joined by dividing the molten steel discharge path in a vertical direction to a nozzle structure for molten steel discharge provided in one or more places, in the inner hole surface of the nozzle structure, the inner bore sleeve of refractory There is disposed so as to straddle at least one of the vertical direction of the joint portion, the nozzle structure.
[Claim 2]
　It said bore sleeve is installed in the bore surface through the adhesive, the nozzle structure according to claim 1.
[Claim 3]
　The upper end of the inner hole side of the bore sleeve is a curved surface or inclined surfaces, the nozzle structure according to claim 1 or claim 2.
[Claim 4]
　The outer periphery of the bore sleeve a horizontal position corresponding to the one or more joints, was placed one or more non-contiguous recess or continuous groove, according to any one of claims 1 to 3 nozzle structure.
[Claim 5]
　The one or more discontinuous recess or continuous groove, relatively more placed on either or both surfaces of the front and rear pressing direction for the sliding direction or dismantling removed below the nozzle from the joints the nozzle structure according to claim 4.
[Claim 6]
　Refractory high-adhere than refractory of the nozzle structure body, a nozzle structure according to any one of claims 1 to 5 forming the bore sleeve.
[Claim 7]
　The bore sleeve, the CaO component about 15 wt% or more, containing MgO to the remainder, CaO / MgO weight ratio consists refractory of 0.1 to 1.5, the nozzle structure according to claim 6 body.