CN104128575B - The continuous tapering acquisition methods of benchmark parabola and device on a kind of crystallizer - Google Patents

Abstract

The present invention is applicable to steel-making continuous casting field, provides the continuous tapering acquisition methods of benchmark parabola on a kind of crystallizer and device, and described method comprises calculating crystallizer position of upper tapering; Calculate total tapering in length of mould direction; According to described position of upper tapering and total tapering, calculate at the tapering of length direction apart from any position suitable for reading.By the crystallizer that the present invention program obtains, in it, the base shell of strand and crystallizer wall what position in office all keep good contact, achieve heat transfer efficiency high between strand and crystallizer, thus improve slab quality, improving casting speed, providing important guarantee for realizing high efficiency continuous casting.

Description

The continuous tapering acquisition methods of benchmark parabola and device on a kind of crystallizer

Technical field

The invention belongs to steel-making continuous casting field, particularly relate to the continuous tapering acquisition methods of benchmark parabola on a kind of crystallizer and device.

Background technology

Crystallizer is the heart of conticaster, and formulates the core that conical degree of crystallizer is Latent Heat process, the slab quality that its reasonability formulated directly decides the attainable pulling rate scope of conticaster and casts.If conical degree of crystallizer arranges too small, then can make easily to produce air gap between base shell and crystallizer wall, thus the heat transfer affected between strand and crystallizer, cause the inhomogeneous growth of base shell in crystallizer, the air gap that the inhomogeneities of this shell growth process can be aggravated between base shell and crystallizer wall conversely produces, and then produces the slab quality problems such as such as Longitudinal Surface Cracks; If conical degree of crystallizer arranges too much, then can aggravate the wearing and tearing of copper plate of crystallizer, increase resistance of billet withdrawal simultaneously, and then produce the slab quality problems such as such as surperficial transverse fissure; And all these are because tapering is arranged, and the unreasonable impact brought all can produce restriction to casting speed.For this reason, the tapering reasonably formulating crystallizer in casting process has the realistic meaning of highly significant.

Summary of the invention

In view of the above problems, the object of the present invention is to provide the continuous tapering acquisition methods of benchmark parabola on a kind of crystallizer and device, be intended to solve in prior art due to tapering arrange improper, make the base shell of strand in crystallizer and the loose contact of crystallizer wall good, affect the technical problem of slab quality.

On the one hand, on described crystallizer, the continuous tapering acquisition methods of benchmark parabola comprises the steps:

Calculate crystallizer position of upper tapering;

Calculate total tapering in length of mould direction;

According to described position of upper tapering and total tapering, calculate at the tapering of length direction apart from any position suitable for reading.

On the other hand, on described crystallizer, the continuous tapering acquisition device of benchmark parabola comprises:

Tapering computing unit suitable for reading, for calculating crystallizer position of upper tapering;

Total tapering computing unit, for calculating total tapering in length of mould direction;

Tapering distribution computing unit, with according to described position of upper tapering and total tapering, calculates at the tapering of length direction apart from any position suitable for reading.

The invention has the beneficial effects as follows: the theoretical foundation that the present invention is based on the process of billet withdrawal of hot-cast base in crystallizer, with the total tapering on length of mould direction for starting point, obtain the continuous cast mold of the continuous tapering of benchmark parabola, in crystallizer, the base shell of strand and crystallizer wall what position in office all keep good contact, achieve heat transfer efficiency high between strand and crystallizer, thus improve slab quality, improving casting speed, providing important guarantee for realizing high efficiency continuous casting.

Accompanying drawing explanation

Fig. 1 is the flow chart of the continuous tapering acquisition methods of benchmark parabola on the crystallizer that provides of the embodiment of the present invention;

Fig. 2 is the crystallizer vertical profile structure chart that the embodiment of the present invention provides;

Fig. 3 is apart from crystallizer position of upper and crystallizer internal cavity size length of side S in example one _xcurve relation figure;

Fig. 4 is apart from crystallizer position of upper and crystallizer internal cavity size length of side S in example two _xcurve relation figure;

Fig. 5 is the block diagram of the continuous tapering acquisition device of benchmark parabola on the crystallizer that provides of the invention process.

Detailed description of the invention

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

In order to technical solutions according to the invention are described, be described below by specific embodiment.

Fig. 1 shows benchmark parabola continuous tapering acquisition methods flow process on crystallizer that the embodiment of the present invention provides, illustrate only the part relevant to the embodiment of the present invention for convenience of explanation.

On the crystallizer that the present embodiment provides, the continuous tapering acquisition methods of benchmark parabola comprises the steps:

Step S101, calculating crystallizer position of upper tapering;

Total tapering in step S102, calculating length of mould direction.

With reference to the crystallizer vertical profile structure shown in Fig. 2, and set up XYZ coordinate system according to diagram, the selection of the origin of coordinates should make the T tried to achieve ₁the solidification shrinkage characteristic of current cast steel grade in crystallizer is met with the value of T.Square root law is met according to casting blank solidification, and crystallizer change in size and strand contraction phase are worked as, and the expression formula of crystallizer position of upper tapering and total tapering can be obtained respectively as shown in formula (1) and formula (2) according to the definition of conical degree of crystallizer:

$T_1=\frac{k}{a\sqrt{x_1}}\×{10}^5---\left(1\right)$

$T=\frac{2k(\sqrt{x_2}-\sqrt{x_1})}{\mathrm{aL}}\×{10}^5---\left(2\right)$

Wherein k is steel grade coefficient, usually gets 0 ~ 20mm ^1/2, a is the crystallizer length of side suitable for reading, x ₁for crystallizer coordinate suitable for reading, x ₂for crystallizer end opening coordinate, L is crystallizer total length.

Step S103, according to described position of upper tapering and total tapering, to calculate at the tapering of length direction apart from any position suitable for reading.

Can be obtained by formula (1):

$k=T_{1}a\sqrt{x_1}\×{10}^{-5}---\left(3\right)$

In addition, there is geometrical relationship:

L＝x ₂-x ₁(4)

Can obtain in conjunction with formula (2), formula (3) and formula (4):

$\mathrm{TL}={2T}_1\sqrt{x_1}(\sqrt{x_2}-\sqrt{x_1})=T(\sqrt{x_2}+\sqrt{x_1})(\sqrt{x_2}-\sqrt{x_1})---\left(5\right)$

Can obtain thus:

${2T}_1\sqrt{x_1}=T(\sqrt{x_2}+\sqrt{x_1})$

Known further:

$\frac{x_1}{x_2}={\left(\frac{T}{{2T}_1-T}\right)}^2---\left(6\right)$

Simultaneous formula (4) and formula (6), can obtain:

$x_1=\frac{T^{2}L}{{4T}_1(T_1-T)},x_2\frac{{({2T}_1-T)}^{2}L}{{4T}_1(T_1-T)}---\left(7\right)$

Substitute into formula (3), can obtain:

$k=\frac{T_1\mathrm{Ta}\sqrt{L}}{2\sqrt{T_1(T_1-T)}}\×{10}^{-5}---\left(8\right)$

According to the definition of conical degree of crystallizer, in conjunction with formula (7) and formula (8), the tapering Tx that can obtain any position in crystallizer is:

$\begin{array}{c}{T}_x=\frac{2k(\sqrt{x_1+x+\mathrm{\Δx}}-\sqrt{x_1+x})}{a(x_1+x+\mathrm{\Δx}-x_1-x)}\×{10}^5=\frac{2k}{a}\left(\frac{\sqrt{x_1+x+\mathrm{\Δx}}-\sqrt{x_1+x}}{\mathrm{\Δx}}\right)\×{10}^5=\frac{2k}{a}{\left(\sqrt{x_1+x}\right)}^{/}\×{10}^5\\ =\frac{T_{1}T\sqrt{L}}{2\sqrt{T_1(T_1-T)}}\frac{1}{\sqrt{x_1+x}}\\ =\frac{T_{1}T\sqrt{L}}{2\sqrt{T_1(T_1-T)}}\frac{1}{\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}+x}}\end{array}---\left(9\right)$

Finally according to the continuous tapering distribution in length of mould direction, obtained corresponding crystallizer.When using this crystallizer to carry out steel-making continuous casting, in crystallizer, the base shell of strand and crystallizer wall what position in office all keep good contact, achieve heat transfer efficiency high between strand and crystallizer, thus improve slab quality, improving casting speed, providing important guarantee for realizing high efficiency continuous casting.

Be further used as preferred, this implementation method also comprises the steps:

Step S104, according to described position of upper tapering and total tapering, to calculate in the crystallizer internal cavity length of side of length direction apart from any position suitable for reading.

In step s 103, calculate the tapering distribution of crystallizer in the longitudinal direction according to the position of upper tapering obtained and total tapering, the structure of crystallizer can be determined by tapering distribution.The structure of crystallizer can certainly be determined by the inner chamber length of side distribution of crystallizer.In this preferred steps, calculate the distribution of the crystallizer internal cavity length of side by position of upper tapering and total tapering.

The inner chamber length of side S that distance crystallizer distance suitable for reading is x place can be calculated according to formula (7) and (8) _xas follows:

$\begin{array}{c}{S}_x=a-2k(\sqrt{x_1+x}-\sqrt{x_1})\\ =a(1-\frac{T_{1}T\sqrt{L}}{\sqrt{T_1(T_1-T)}}(\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}+x}-\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}})\×{10}^{-5})\end{array}---\left(10\right)$

Provide two concrete calculated examples below.

Example one:

Casting high-carbon steel, casting blank specification is the square billet of 200mm × 200mm, and length of mould is 900mm, and crystallizer is suitable for reading is of a size of 203.27mm, and crystallizer position of upper is 37.5mm.

As the above analysis, L=900mm, a=203.27mm, x ₁=37.5mm, x ₂=937.5mm; Correspondingly get k=0.0385mm ^1/2.

1.1 calculate crystallizer position of upper tapering T ₁:

$T_1=\frac{k}{a\sqrt{x_1}}\×{10}^5=3.09\%/m;$

1.2 calculate the total tapering T on length of mould direction:

$T=\frac{2k(\sqrt{x_2}-\sqrt{x_1})}{\mathrm{aL}}\×{10}^5=1.03\%/m;$

1.3 calculate the crystallizer internal cavity length of side S apart from any position x suitable for reading _x:

$S_x=203.7411-0.07693\sqrt{37.5+x}\mathrm{mm};$

1.4 calculate the tapering T apart from any position of any position x suitable for reading _x:

$T_x=\frac{18.9223}{\sqrt{37.5+x}}\%/m;$

Apart from crystallizer position of upper x and crystallizer internal cavity size length of side S _xcurved line relation as shown in Figure 3.

Example two:

Cast alloys steel, casting blank specification is the square billet of 600mm × 600mm, and length of mould is 900mm, and crystallizer is suitable for reading is of a size of 610.73mm, and crystallizer position of upper is 37.5mm.

As the above analysis, L=900mm, a=610.73mm, x ₁=37.5mm, x ₂=937.5mm; Correspondingly get k=0.1346mm ^1/2.

2.1 calculate crystallizer position of upper tapering T ₁:

$T_1=\frac{k}{a\sqrt{x_1}}\×{10}^5=3.6\%/m;$

2.2 calculate the total tapering T on length of mould direction:

$T=\frac{2k(\sqrt{x_2}-\sqrt{x_1})}{\mathrm{aL}}\×{10}^5=1.2\%/m;$

2.3 calculate the crystallizer internal cavity length of side S apart from any position x suitable for reading _x:

$S_x=612.3790-0.2693\sqrt{37.5+x}\mathrm{mm};$

2.4 calculate the tapering T apart from any position x suitable for reading _x:

$T_x=\frac{22.0454}{\sqrt{37.5+x}}\%/m.$

Apart from crystallizer position of upper x and crystallizer internal cavity size length of side S _xcurved line relation as shown in Figure 4.

In addition, as shown in Figure 3, the embodiment of the present invention additionally provides the continuous tapering acquisition device of benchmark parabola on a kind of crystallizer, comprising:

Tapering computing unit 31 suitable for reading, for calculating crystallizer position of upper tapering;

Total tapering computing unit 32, for calculating total tapering in length of mould direction;

Tapering distribution computing unit 33, with according to described position of upper tapering and total tapering, calculates at the tapering of length direction apart from any position suitable for reading.

Preferably, described device also comprises:

Inner chamber length of side computing unit 34, for according to described position of upper tapering and total tapering, calculates in the crystallizer internal cavity length of side of length direction apart from any position suitable for reading.

Wherein, described crystallizer position of upper tapering wherein k is steel grade coefficient, and a is the crystallizer length of side suitable for reading, x ₁for crystallizer coordinate suitable for reading.

Total tapering in described length of mould direction wherein x ₂for crystallizer end opening coordinate, L is crystallizer total length.

The described tapering apart from any position suitable for reading wherein x is from distance length suitable for reading at length direction; The described crystallizer internal cavity length of side apart from any position suitable for reading $S_x=a(1-\frac{T_{1}T\sqrt{L}}{\sqrt{T_1(T_1-T)}}(\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}+x}-\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}})\×{10}^{-5}).$

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (5)

1. the continuous tapering acquisition methods of benchmark parabola on crystallizer, it is characterized in that, described method comprises:

Calculate crystallizer position of upper tapering;

Calculate total tapering in length of mould direction;

According to described position of upper tapering and total tapering, calculate at the tapering of length direction apart from any position suitable for reading;

Described method also comprises:

According to described position of upper tapering and total tapering, calculate in the crystallizer internal cavity length of side of length direction apart from any position suitable for reading;

Wherein said crystallizer position of upper tapering wherein k is steel grade coefficient, and a is the crystallizer length of side suitable for reading, x ₁for crystallizer coordinate suitable for reading.

2. method as claimed in claim 1, is characterized in that, total tapering in described length of mould direction wherein x ₂for crystallizer end opening coordinate, L is crystallizer total length.

3. method as claimed in claim 2, is characterized in that, the described crystallizer internal cavity length of side apart from any position suitable for reading $S_x=a(1-\frac{T_{1}T\sqrt{L}}{\sqrt{T_1(T_1-T)}}(\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}+x}-\sqrt{\frac{T^{2}L}{4T_1(T_1-T)}}\×{10}^{-5}),$ Wherein x is from distance length suitable for reading at length direction.

4. method as claimed in claim 3, is characterized in that, the described tapering apart from any position suitable for reading wherein x is from distance length suitable for reading at length direction.

5. the continuous tapering acquisition device of benchmark parabola on crystallizer, it is characterized in that, described device comprises:

Tapering computing unit suitable for reading, for calculating crystallizer position of upper tapering;

Total tapering computing unit, for calculating total tapering in length of mould direction;

Tapering distribution computing unit, for according to described position of upper tapering and total tapering, calculates at the tapering of length direction apart from any position suitable for reading;

Described device also comprises:

Inner chamber length of side computing unit, for according to described position of upper tapering and total tapering, calculates in the crystallizer internal cavity length of side of length direction apart from any position suitable for reading;

Wherein said crystallizer position of upper tapering wherein k is steel grade coefficient, and a is the crystallizer length of side suitable for reading, x ₁for crystallizer coordinate suitable for reading.