CN109759574B

CN109759574B - Low-Young modulus submerged nozzle lining material

Info

Publication number: CN109759574B
Application number: CN201910237236.XA
Authority: CN
Inventors: 王昆鹏; 徐建飞; 谢友; 万文华
Original assignee: Changzhou Bangyi Steel Co ltd; Zenith Steel Group Co Ltd
Current assignee: Changzhou Bangyi Iron and Steel Co., Ltd.
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2020-10-16
Anticipated expiration: 2039-03-27
Also published as: CN109759574A

Abstract

The invention discloses a submerged nozzle lining material with low Young's modulus, belonging to the field of functional fire-resistant materials for continuous casting in the ferrous metallurgy industry. Characterized by the Young's modulus of the lining material of the nozzleIs lower than the produced steel matrix, and specifically comprises 90-95% of magnesium oxide as a compounding ingredient, and 5-10% of phenolic resin as a binding agent. The magnesium oxide has a particle size of 0.1mm-1.0mm, and the density of magnesium oxide particles should not exceed 3.35g/cm³The optimal density range is 3.0-3.3g/cm³The thickness of the lining is 3-8 mm. The Young modulus of the lining material is lower than that of a steel matrix, the lining material can be broken in the drawing process, and the broken filaments of the ultra-deep drawing wire rod caused by melting loss and stripping of the refractory material can be obviously reduced.

Description

Low-Young modulus submerged nozzle lining material

Technical Field

The invention belongs to the field of refractory materials, and relates to a submerged nozzle lining material for continuous casting.

Background

Ultra-deep drawing metal products represented by bead wires, steel cords, and diamond wires have very strict requirements for inclusions in the wire rod base material. Once large-size non-deformation inclusions exist in steel, the steel wire can be broken in the drawing or stranding process, and frequent wire breakage seriously affects the production efficiency of the steel wire and even leads to direct scrapping of the steel wire. Research shows that the melting loss and the stripping of refractory materials in the submerged nozzle are main sources of large-size invariant clamp impurities under the smelting process conditions of silicon-manganese deoxidation and low-alkalinity slag refining.

In order to solve the problem that the submerged nozzle introduces large-size non-deformable inclusions, the Chinese patent CN 201537698U discloses a design of a four-hole submerged nozzle. The design has two main points, firstly, the floating of impurities is improved through the design of the four-hole water gap, and secondly, the problem that aluminum impurities are brought into a common immersion type water gap during casting is solved by adopting magnesium carbon as a water gap body. However, the patent does not specifically require a magnesium carbonaceous material. In fact, any type of submerged entry nozzle material cannot completely avoid melting loss and flaking during steel casting. Although the magnesium-carbon refractory material solves the problem of aluminum-containing inclusion, magnesium-containing inclusion is introduced, and the magnesium-containing inclusion with high Young modulus can also cause wire breakage in the wire rod drawing and stranding processes.

The refractory aggregate at present comprises alumina, magnesia-alumina spinel, mullite, zirconia and the like, the Young modulus of the refractory aggregate is larger than that of a steel matrix, stress concentration is formed in the drawing process, and the wire breakage is caused by drawing, so that the problem of wire breakage of an ultra-deep drawing wire caused by melting loss and stripping of a refractory material of an immersion nozzle is urgently needed to be researched by a low-Young modulus lining material of the immersion nozzle.

Disclosure of Invention

Aiming at the problem of wire breakage of ultra-deep drawing wires caused by melting loss and stripping of refractory materials of an immersion nozzle, the invention aims to provide a nozzle lining material with a Young modulus lower than that of a steel matrix.

In order to achieve the purpose, the invention adopts the technical scheme that: a submerged nozzle lining material with low Young's modulus. The Young modulus of the nozzle lining material is lower than that of the produced steel substrate.

The specific scheme is as follows: the weight percentage of the components is as follows:

the ingredients are 90-95% of magnesium oxide, and 5-10% of phenolic resin is added as a binding agent. The magnesium oxide has a particle size of 0.1mm-1.0mm, and the density of magnesium oxide particles should not exceed 3.35g/cm³Further preferably, the density is 3.0 to 3.3g/cm³The thickness of the lining is 3-8 mm.

Compared with the prior art, the invention has the beneficial effects that:

the submerged nozzle lining material with low Young's modulus provided by the invention utilizes low-density low-Young's modulus magnesium oxide as a main raw material, so that the cost of the raw material can be reduced, and the Young's modulus of the lining material is lower than that of a steel matrix, so that the lining material can be broken in the drawing process, and the wire breakage of an ultra-deep drawing wire rod caused by the melting loss and stripping of a refractory material can be remarkably reduced.

Drawings

FIG. 1 is a graph showing the Young's modulus of magnesium oxide as a function of density, and the density is less than 3.35g/cm³The young's modulus of magnesium oxide of (2) is lower than 200GPa (young's modulus of steel);

FIG. 2 is a schematic view of the submerged entry nozzle liner of the present invention;

FIG. 3 is a graph of the high Young's modulus magnesium oxide of comparative example 1 during the drawing process;

FIG. 4 shows the morphology of the low Young's modulus magnesium oxide of example 1 during the drawing process.

Detailed Description

The invention is described in further detail below with reference to the figures and the embodiments.

As shown in figure 1, the submerged nozzle lining material with low Young's modulus comprises 90-95% of magnesium oxide and 5-10% of phenolic resin as a bonding agent.

The particle size of the magnesium oxide is 0.1-1.0 mm.

The density of the magnesium oxide particles is not more than 3.35g/cm³Preferably, the density is in the range of 3.0 to 3.3g/cm³. (the bulk density of magnesium oxide is commercially available)

The thickness of the lining is 3-8 mm.

Example 1

The submerged nozzle lining material with low Young's modulus is prepared with magnesia in 93 wt% and phenolic resin in 7 wt% as the binding agent. The particle size of the magnesium oxide is 0.1mm-1.0mm, and the density of the magnesium oxide particles is 3.13g/cm³And the thickness of the lining is 5 mm.

Example 2

The submerged nozzle lining material with low Young's modulus is prepared with magnesia in 90 wt% and phenolic resin in 10 wt% as the binding agent. The particle size of the magnesium oxide is 0.1mm-1.0mm, and the density of the magnesium oxide particles is 3.0g/cm³And the thickness of the lining is 3 mm.

Example 3

Low Young's modulus quantizationThe submerged nozzle lining material is prepared by mixing the following raw materials in percentage by weight, 95 percent of magnesium oxide and 5 percent of phenolic resin as a bonding agent. The particle size of the magnesium oxide is 0.1mm-1.0mm, and the density of the magnesium oxide particles is 3.24g/cm³And the thickness of the lining is 6 mm.

Example 4

A submerged nozzle lining material with low Young's modulus is prepared by mixing the following raw materials in percentage by weight, 94% of magnesium oxide and 6% of phenolic resin as a binding agent. The particle size of the magnesium oxide is 0.1mm-1.0mm, and the density of the magnesium oxide particles is 3.27g/cm³And the thickness of the lining is 7 mm.

Example 5

The submerged nozzle lining material with low Young's modulus is prepared with magnesia in 92 wt% and phenolic resin in 8 wt% as the binding agent. The particle size of the magnesium oxide is 0.1mm-1.0mm, and the density of the magnesium oxide particles is 3.29g/cm³And the thickness of the lining is 8 mm.

Comparative example 1

Comparative example 1 in comparison with example 1, the density of the magnesium oxide particles in example 1 was set to 3.13g/cm³Replacement by a density of 3.7g/cm of magnesium oxide particles³The other conditions are the same, and specifically comprise:

the submerged nozzle lining material provided by the comparative example 1 is prepared by mixing the following raw materials in percentage by weight, 93% of magnesium oxide, and 7% of phenolic resin as a bonding agent. The particle size of the magnesium oxide is 0.1mm-1.0mm, and the density of the magnesium oxide particles is 3.7g/cm³And the thickness of the lining is 5 mm.

In order to test the effect of the invention, the submerged nozzle is prepared by compounding the lining material and the body material, the proportion of the lining of the long nozzle of the sample 1-5 is respectively according to the proportion of the example 1-5, the proportion of the lining of the long nozzle of the comparative example is according to the proportion of the comparative example 1, and the weight percentage of the body material is as follows: 55% of corundum, 15% of fused quartz, 20% of graphite and 8% of phenolic resin as a binding agent, drying the body material and the lining material at 60 ℃, controlling the volatile content to be 1%, carrying out isostatic pressing on the body material and the lining material under 150MPa of pressure, carrying out heat treatment at 1000 ℃, and carrying out heat preservation for 6 hours. The manufactured submerged nozzle is used for the production of the cord steel 82A.

Test example 1

The casting blanks produced by the processes described in example 1 and comparative example 1 were hot rolled to specification

The hot rolled wire rod is drawn into a steel wire by multiple passes, and the diameter of the intermediate sample has

The diameter of the final drawing finished steel wire is

A drawing intermediate sample having a diameter of 2.0mm was sampled, and the morphology of magnesium oxide inclusions in the steel was examined using a scanning electron microscope.

FIG. 3 shows the diameter of comparative example 1

The intermediate sample (2) has a form of magnesium oxide inclusion, and the magnesium oxide inclusion particles are coarse and insufficiently deformed, and have a maximum width of approximately 20 μm.

FIG. 4 shows the diameter of example 1

The intermediate sample (2) has a form of magnesium oxide inclusion, the magnesium oxide is sufficiently deformed in the drawing direction, and the maximum width is less than 1 μm.

Test example 2

The casting blanks produced by the processes described in example 1, example 2, example 3, example 4, example 5 and comparative example 1 were hot rolled to specification

The diameter of the final drawing finished steel wire is

The wire breakage per ton of steel wire rods obtained from example 1, example 2, example 3, example 4 and example 5 was counted and as shown in table 1, the wire breakage per ton of steel wire rods was 0.85 times per ton, 0.63 times per ton, 0.79 times per ton, 0.97 times per ton and 1.03 times per ton, which was significantly lower than that of 2.34 times per ton of steel in comparative example 1.

TABLE 1 wire breakage rate of steel wire rod for producing cord thread from nozzle inner lining of different materials

Item	Wire breakage times per ton of steel, times per ton of steel
		Example 1	0.85
Example 2	0.63
		Example 3	0.79
Example 4	0.97
		Example 5	1.03
Comparative example 1	2.34

As described in the above test examples 1 and 2, even when the "submerged nozzle lining material with a low young's modulus" proposed by the present invention is melted and peeled into steel, such magnesium oxide with a low young's modulus may be broken and separated during the wire rod drawing process, and the present invention can significantly reduce the wire breakage caused by melting and peeling of the refractory lining material of the submerged nozzle.

Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.

Claims

1. The utility model provides a low immersion nozzle lining material of young's modulus quantization which characterized in that: the water gap lining material comprises, by weight, 90-95% of magnesium oxide, and 5-10% of phenolic resin as a binding agent, wherein the density of magnesium oxide particles is not more than 3.35g/cm³The Young modulus of the lining material of the magnesia nozzle is lower than that of the produced steel matrix.

2. The submerged entry nozzle lining material with a low young's modulus as claimed in claim 1, wherein: the density of the magnesium oxide particles is 3.0-3.3g/cm³。

3. The submerged entry nozzle lining material with a low young's modulus as claimed in claim 1, wherein: the granularity of the magnesium oxide is 0.1mm-1.0mm, and the thickness of the lining is 3-8 mm.