阅读说明：本技术 一种中频炉炉衬 (Intermediate frequency furnace lining ) 是由 张新宇 李栋 展益彬 刘立国 吴玉同 李慧 于 2019-09-06 设计创作，主要内容包括：本发明公开了一种中频炉炉衬。该炉衬由炉衬本体、渣线层和透气塞组成。透气塞为弥散式透气,位于炉底中心。渣线层位于炉衬本体的上部,采用渣线砖砌筑,所述渣线砖在安装平面上分别加工相互配合的凸块和凹槽,两个安装平面夹角为15°,渣线砖的外圆弧与炉衬本体的外圆尺寸一致,内圆弧与炉衬本体的内圆尺寸一致,渣线砖与炉衬本体接触的上下表面均匀遍布有凸尖。该炉衬可实现钢水净化,为生产优质铸件提供了条件。使用该炉衬冶炼的钢水,其气体含量及硫磷含量达到精炼水平,合金元素收得率大大增加。(The invention discloses a furnace lining of an intermediate frequency furnace. The furnace lining consists of a furnace lining body, a slag line layer and a ventilation plug. The ventilation plug is dispersedly ventilated and is positioned in the center of the furnace bottom. The slag line layer is located on the upper portion of the furnace lining body and built by adopting slag line bricks, the slag line bricks are respectively provided with a convex block and a concave groove which are matched with each other on the installation planes, the included angle between the two installation planes is 15 degrees, the outer circular arc of the slag line bricks is consistent with the outer circular dimension of the furnace lining body, the inner circular arc is consistent with the inner circular dimension of the furnace lining body, and convex points are uniformly distributed on the upper surface and the lower surface of the slag line bricks, which are contacted with the furnace lining body. The furnace lining can realize molten steel purification and provides conditions for producing high-quality castings. The gas content and sulfur and phosphorus content of the molten steel smelted by the furnace lining reach the refining level, and the yield of the alloy elements is greatly increased.)

1. An intermediate frequency furnace lining which is characterized in that: the magnesia-alumina spinel furnace lining comprises a magnesia-alumina spinel furnace lining body (1), a slag line layer (2) and a high-alumina ventilation plug (3); the ventilation plug (3) is dispersedly ventilated and is positioned in the center of the furnace bottom; the slag line layer is positioned at the upper part of the furnace lining body (1) and is built by special slag line bricks, and the slag line bricks are magnesia carbon bricks and are higher than the refining slag layer; the slag line brick is characterized in that a lug (4) and a groove (5) which are matched with each other are processed on a mounting plane, and the included angle between the two mounting planes is 15 degrees; the difference value of the radiuses of the two arc surfaces of the slag line brick is the thickness of the furnace lining, the outer arc of the slag line brick is consistent with the outer circle of the furnace lining body (1), and the inner arc of the slag line brick is consistent with the inner circle of the furnace lining body (1); the upper and lower surfaces of the slag line brick, which are contacted with the furnace lining body (1), are uniformly distributed with the convex tips (6).

2. The intermediate frequency furnace lining according to claim 1, characterized in that: the number of the convex blocks (4) or the concave grooves (5) on the mounting plane is two.

Technical Field

The invention is applied to the field of casting, and particularly relates to an intermediate frequency furnace lining for molten steel smelting.

Background

in the casting industry, an intermediate frequency furnace is mostly adopted for cast steel smelting, and due to the limitation of a furnace lining of the intermediate frequency furnace, molten steel smelting is always in contact with air, so that the molten steel cannot be purified, and high-quality cast steel cannot be produced.

The furnace lining of the intermediate frequency furnace is generally divided into an acid furnace lining, a neutral furnace lining and an alkaline furnace lining. The acidic furnace lining takes silicon oxide as a main component, the neutral furnace lining takes aluminum oxide as a main component, and the alkaline furnace lining takes magnesium oxide as a main component. Because the melting point of the acid furnace lining is low and the thermal shock property of the basic furnace lining is poor, the neutral furnace lining or the magnesium aluminate spinel basic furnace lining is mostly adopted for the smelting of cast steel. However, the neutral alumina lining cannot be used for slagging and purifying molten steel, so that a magnesia-alumina spinel basic lining is required. Even if the service life of the furnace lining is very short, under the general condition that other parts of the furnace lining are good, the furnace lining is extremely seriously corroded at the slag line position for slagging, and a furnace leakage accident can be caused by one furnace, so that the intermediate frequency furnace can not make steel from the casting industry.

Disclosure of Invention

The technical problem solved by the invention is as follows: provides a furnace lining of an intermediate frequency furnace, meets the requirement of producing reducing slag, purifies molten steel and produces high-quality steel castings.

The technical scheme adopted by the invention is as follows: the intermediate frequency furnace lining consists of a magnesia-alumina spinel furnace lining body, a slag line layer and a high-alumina ventilation plug. The ventilating plug is dispersedly ventilated and is positioned in the center of the furnace bottom. The slag line layer is positioned at the upper part of the furnace lining body and built by special slag line bricks, the slag line bricks are magnesia carbon bricks, the height of the slag line bricks is greater than the thickness of the slag layer of the reducing slag, the slag line bricks are provided with two lugs and two grooves which are matched with each other on the mounting plane, the two lugs or the two grooves are optimally designed on the mounting plane, and the included angle of the two mounting planes of the slag line bricks is 15 degrees; the difference value of the radiuses of the two arc surfaces of the slag line brick is the thickness of the furnace lining, the outer arc of the slag line brick is consistent with the outer circle of the furnace lining body, and the inner arc of the slag line brick is consistent with the inner circle of the furnace lining body; the convex tips are uniformly distributed on the upper and lower surfaces of the slag line brick, which are contacted with the furnace lining body.

The invention has the beneficial effects that: the furnace lining can produce reducing slag, realizes the purpose of purifying molten steel by the intermediate frequency furnace, and provides conditions for producing high-quality castings in the casting industry. The gas content and sulfur and phosphorus content of the molten steel smelted by the furnace lining reach the refining level, and the yield of the alloy elements is greatly increased.

drawings

FIG. 1 is a schematic view of a furnace lining structure according to the present invention;

FIG. 2 is a top view of a slag line brick;

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a schematic plan view of a slag line brick furnace lining;

FIG. 5 is a second construction of a slag line brick;

FIG. 6 is a third structural form of the slag line brick;

FIG. 7 is a fourth structural form of the slag line brick;

Wherein: 1-furnace lining body, 2-slag line layer, 3-ventilation plug, 4-bump, 5-groove and 6-convex tip.

Detailed Description

FIG. 1 is a schematic diagram of the lining structure of an intermediate frequency furnace in the invention. The intermediate frequency furnace lining is composed of a furnace lining body 1, a slag line layer 2 and a ventilation plug 3. In order to meet the requirements of high-temperature smelting and cost of cast steel, the furnace lining body 1 is made of magnesium aluminate spinel, the slag line layer is made of slag line bricks with the structures shown in the attached figures 2-3, and the slag line bricks are magnesia carbon bricks and can meet the requirement of slagging of reducing slag. The ventilation plug 3 is made of high-alumina refractory material, is diffused and ventilated, is positioned in the center of the furnace bottom, and blows inert gas from the middle-frequency furnace bottom to promote the purification of molten steel.

The attached drawings 2 and 3 are respectively a top view and a front view of the slag line brick, the slag line brick is respectively provided with a convex block 4 and a groove 5 which are matched with each other on an installation plane, preferably two convex blocks 4 or two grooves 5 are arranged on the installation plane, the schematic plane of a furnace lining formed by the matched installation of the convex blocks 4 and the grooves 5 is shown in the attached drawings 4, the matching between the convex blocks 4 and the grooves 5 has the positioning function and also has the function of increasing the sealing function, and the molten steel is prevented from penetrating through a slag line layer to cause steel leakage. The included angle of the two installation planes is 15 degrees, and the included angle of 15 degrees ensures that the slag line bricks can be combined into a closed perfect circle. The difference value of the two arc radiuses of the slag line brick is the thickness of the furnace lining, the size of the outer arc is consistent with that of the outer circle of the furnace lining body 1, and the size of the inner arc is consistent with that of the inner circle of the furnace lining body 1. The convex tips 6 are uniformly distributed on the plane contacted with the upper and lower furnace lining bodies, and the convex tips 6 can increase the binding force with the upper and lower furnace lining bodies.

Fig. 5, 6 and 7 are different structural forms of the slag line brick respectively, and are different from fig. 2 in the shape, position and number of the convex blocks 4 and the concave grooves 5. The shapes of the similar mutually engageable projections 4 and recesses 5 are not to be enumerated.

the molten steel smelted by the furnace lining of the intermediate frequency furnace can be subjected to oxidative dephosphorization, reduction slag deoxidation, desulfurization and alloying, and the molten steel can be purified by blowing inert gas from the furnace bottom. Because the magnesia carbon brick cannot tolerate the oxidizing slag, the oxidizing dephosphorization of the molten steel is preferably carried out in a steel ladle, after slagging off, the dephosphorized molten steel is poured into an intermediate frequency furnace to produce reducing slag, alloying and bottom blowing argon are carried out to purify the molten steel. The specific smelting steps comprise: 1) and (4) an oxidation period. Melting metal raw materials, tapping molten steel into a steel ladle, adding slagging auxiliary materials such as lime and the like, and blowing oxygen to remove phosphorus from the steel pipe. Removing oxidation slag in the ladle, and pouring the deoxidized molten steel into an intermediate frequency furnace; 2) and (4) a reduction period. Before the molten steel is used for manufacturing reducing slag, the liquid level of the molten steel is not lower than the bottommost line of a slag line layer. Adding slagging auxiliary materials such as lime and the like for melting, and simultaneously adding a deoxidizing agent for producing reducing slag, wherein the thickness of the reducing slag is not less than 50mm, and the thickness of a slag layer is within the height range of the slag line brick; 3) alloying purification period. Sampling and analyzing in the state of reducing slag, adding alloy material for alloying, blowing argon at the bottom of the furnace to purify molten steel, and stirring the molten steel to prevent the reducing slag layer from being exposed. In the process of stirring the molten steel, the inclusions in the molten steel float upwards along with the stirring of the molten steel and react with the reducing slag at a steel slag interface to realize deoxidation and desulfurization, and other inclusions are bonded with the reducing slag and separated from the molten steel, so that the aim of removing oxides, sulfides and other inclusions in the molten steel is fulfilled. Meanwhile, the argon blown into the molten steel can adsorb nitrogen, hydrogen and oxygen in the molten steel, and the gases are taken out of the molten steel, so that the effect of reducing the gas content in the molten steel is realized. After the components of the molten steel are adjusted to be qualified, heating to prepare tapping; 4) the steel slag is mixed out during tapping, the reaction interface of the steel slag is increased, and impurities are further removed. And removing the reducing slag in the ladle, adding the covering slag, melting and hoisting to a casting station.

If the molten steel does not need the oxidation period, the oxygen blowing oxidation period in the ladle can be removed in the smelting step, and after the molten steel is melted, reducing slag is directly produced for molten steel purification treatment.

The furnace lining and the steel ladle, in particular to the use of the magnesia carbon slag line brick, change the traditional view that the intermediate frequency furnace can not make steel, realize the processes of intermediate frequency furnace smelting, dephosphorization in an oxidation period, deoxidation and desulfurization in a reduction period, argon refining before tapping and the like, ensure that the intermediate frequency furnace can smelt and purify molten steel, and provide smelting conditions for producing high-quality castings in the casting industry.

the furnace lining of the intermediate frequency furnace not only meets the requirement of producing reducing slag, greatly reduces the content of impurities in molten steel and achieves the aim of purifying the molten steel, but also can improve the yield of alloy elements during alloying. The following table 1 shows the alloying yield of each alloy element when high alloy steel such as stainless steel is smelted, and the yield of Ti and Al elements is obviously improved and is improved by more than 2 times compared with the conventional yield of about 30 percent. The yield of Cr and Mo alloy elements is 100 percent, which is higher than the conventional yield of 90-96 percent.

TABLE 1 yield of alloying elements

Element(s)	Cr	Ni	Mo	Cu	Nb	Ti	W	V	Al
										Yield of the product	100%	100%	100%	100%	100%	60-85%	100%	100%	60-85%

when the intermediate frequency furnace lining is used, the gas content and the sulfur and phosphorus content after molten steel purification reach the refining level. Table 2 shows that the gas content and sulfur and phosphorus content of molten steel during the smelting of low alloy steel are equivalent to the refining level of steelmaking, and the smelting quality reaches the refining level.

TABLE 2 harmful element content

element(s)	N/ppm	H/ppm	O/ppm	P/%	S/%
						Content (wt.)	80-180	1.2-2.2	30-110	0.015-0.025	0.004-0.009