KR101299355B1 - Method for producing of H-steel - Google Patents

Abstract

The present invention relates to a method for manufacturing H-shaped steel, in the production of H-shaped steel in the H-shaped steel production line larger than the standard of the H-shaped steel to be produced, the upper and lower roll width of the roughing mill is adjusted and the reduction ratio of the flange compared to the web And roughly rolling the rolled material by raising the rolling material, and rolling the roughly rolled rolled material by increasing the rolling reduction of the web compared to the flange in the first continuous mill.
Advantageous Effects of the Invention The present invention provides an advantage of preventing over-aging of the flange and securing ease of insertion of the rolled material through the adjustment of the roll width due to the double R machining, the adjustment of the web thickness during rough rolling, and the increase of the flange length in the first continuous mill. There is this.

Description

Method for producing H-shaped steel {Method for producing of H-steel}

The present invention relates to a H-shaped steel manufacturing method, and more particularly to a H-shaped steel manufacturing method for producing H-shaped steel in the H-shaped steel production line larger than the standard of the H-shaped steel to be produced.

H-beam means the section steel whose cross-sectional shape has H shape. H-beams are widely used as structural materials such as pillars of large buildings, and are also used as temporary construction materials and foundation piles for subways and bridges.

H-beams are manufactured by hot rolling using cast, such as bloom, billet, beam blank, etc., produced by continuous casting.

An object of the present invention is to provide an H-shaped steel manufacturing method for producing H-shaped steel with stable rolling and H-shaped steel production in the H-shaped steel production line larger than the specification of the H-shaped steel to be produced, without the occurrence of edging will be.

According to the characteristics of the present invention for achieving the object as described above, the present invention is to adjust the upper and lower roll width of the rough rolling machine when the H-shaped steel production in the H-shaped steel production line larger than the specification of the H-shaped steel to be produced And roughly rolling the rolled material by increasing the rolling reduction ratio of the flange relative to the web, and rolling up the roughly rolled rolled material by increasing the rolling reduction of the web relative to the flange in the first continuous mill.

The upper and lower roll width adjustment of the roughing mill is adjusted by double R machining the edges of the upper and lower rolls constituting the roughing mill.

The double R is a difference between an upper R value R1 and a lower R value R2 based on an inflection point at edges of the upper and lower rolls.

The lower R value R2 is larger than the upper R value R1.

The continuous mill mill rolls the rolled material while gradually decreasing the upper and lower roll widths from the first continuous mill mill to the last continuous mill mill.

The present invention prevents over-aging of the flange and ensures easy insertion of the rolled material through the roll width adjustment due to the double R machining, the web thickness adjustment during the rough rolling, and the increase in the flange length in the first continuous mill.

Therefore, even in the case of producing H-beams in the H-beam production line where the specification is larger than the specification of H-beams to be produced, a stable hot rolling process is possible to increase the productivity of the rolled products and reduce the cost and rolling according to the common use of the rolling-line. There is an effect that can increase the convenience.

1 is an embodiment of the H-shaped steel manufacturing method according to the present invention, a schematic view showing a first continuous mill rolling state of the rough rolling material.
2 is a schematic view of a roll to which a roll width adjusting method is applied.
Figure 3 is a flange overaging verification diagram of the rolled material using the plastic deformation analysis program.

Hereinafter, embodiments of the present invention will be described in detail.

The method of manufacturing H-shaped steel of the present invention is a method of manufacturing H-shaped steel which enables stable rolling by preventing flange over edging when H-shaped steel is produced in H-shaped steel production line having a larger standard than the H-shaped steel to be produced. .

The H-shaped steel is made into more sophisticated products through rough rolling, reducing the thickness and width of the rolled material, and from finishing rolling to continuous mill rolling.

In the specific method for manufacturing H-shaped steel, a step of roughly rolling the rolled material by adjusting the upper and lower roll widths of the roughing mill and increasing the rolling reduction ratio of the flange relative to the web, and then rolling the roughened rolled material to the flange in the first continuous milling mill. Comprising the step of increasing the rolling reduction of the web.

The rolled material is a beam blank. The beam blank is a semi-finished product with 'H' shape in cross section, and is mainly used to manufacture H-shaped steel. In the 'H' cross section, the transverse section is called the web, and the longitudinal section on both sides of the web is called the flange.

Roll width adjustment is to prevent a problem in the centering of the rolled material during the insertion of the rolled material.

Rolling is performed by adjusting the gap between the upper and lower rolls in the larger H-beam production line, which is larger than the specification of the H-beam to be produced. In this case, when the gap between the upper and lower rolls is adjusted, the flange is bent due to the high rolling ratio. Aging may occur and problems may occur when the next mill is rolled into the rolled material.

In addition, the over-aging of the flange causes the eccentric deviation of the web and the flange as the excessively bent portion is stretched even when the next rolling mill of the rolled material is possible, adversely affecting the quality of the final product.

Therefore, the rolling reduction ratio of the web and the flange is adjusted in the first continuous milling after the rough rolling and the rough rolling to prevent the overaging of the flange.

1 and 2, the roll width W means the length of the flat straight portion of the roll which comes into contact with the web of the rolled material. The roll width of the roll varies depending on the value of R because the flat straight portion of the roll and the taped straight portions of the roll contacting the web of the rolled material meet the R value. R value is the value which forms curvature in a roll edge, and adjusts roll width by adjusting R value.

Roll width adjustment is performed to ensure ease of insertion of the first continuous mill mill of the rough rolled rolled material.

The upper and lower roll width adjustment of the roughing mill is adjusted by double R machining the edges of the upper and lower rolls constituting the roughing mill. Here, the corner is a portion where the flat straight portions of the rolls contacting the web of the rolled material and the taped both straight portions of the rolls meet as described above.

As shown in FIG. 2, the double R forms two R values having different radii of curvature at the corners of the upper and lower rolls, that is, R1 and R2. That is, the upper R value (R1) and the lower R value (R2) is placed on the corners of the upper and lower rolls based on the inflection point. Depending on the R value, the rolled material has a different position point between the web and the flange, and the rolling reduction ratio of the web and the flange also changes.

In consideration of this, the upper and lower rolls of the roughing mill have a lower R value R2 than the upper R value R1. The lower R value is larger than the upper R value, reducing the amount of flange rolling and preventing flange overaging.

That is, in the rough rolling step, the thickness reduction ratio of the flange is increased compared to the web, so that the web thickness is relatively thick, and the lower R value (R2) is large compared to the upper R value (R1) of the roll, and the rolling is performed in the first continuous mill rolling. By making the flange side of the material a web, the flange is subjected to relatively low pressure reduction even at the same reduction ratio, thereby preventing flange overaging.

In addition, the rough rolled material increases the amount of web reduction in the first continuous mill, thereby suppressing the increase in flange length. This prevents flange overaging and enables stable rolling.

Thereafter, the continuous mill rolling machine gradually rolls the rolled material from the first continuous mill mill to the last continuous mill mill to gradually roll the rolled material into a more precise H shape.

Hereinafter, the present invention will be described in detail with reference to examples. However, it should be noted that the following examples are not limited to the present invention.

<Examples>

For example, the case of manufacturing H-shaped steel of IPE140 standard in the H-beam steel production line for IPE140 (comparative example) and the case of manufacturing H-shaped steel of IPE140 standard in the H-beam steel production line for IPE150 will be described as an example.

The specification of H-beam for IPE150 is H155 × 75 × 6 / 9.5, and the specification of H-beam for IPE140 is H140 × 73 × 4.7 / 6.9.

Roll width adjustment was adjusted by processing R1 at the top of each corner of the upper and lower rolls, R2 at the bottom, and adjusted R1 to 8 to 10R, R2 to 250 to 300R range. The range of R1 and R2 is derived from the plastic deformation analysis program to derive the range in which the excessive reduction force on the flange does not work even at the same reduction ratio.

In the comparative example of manufacturing H-shaped steel of the IPE140 standard in the H-beam steel production line for IPE140, only R was applied without applying double R. R was processed to 12.

After rough rolling, it was processed into H shape by passing through a continuous mill rolling machine consisting of nine rolling mills. In the case of the comparative example, the roll width gradually increased while going to the last continuous mill rolling mill. The width gradually decreased.

Table 1 below shows the normal roll width of the H-shaped steel production line for IPE140 (manufacture of H-shaped steel of IPE140 standard) and the adjustment roll width (manufacture of H-shaped steel of IPE140 standard) for IPE150 H-shaped steel production line according to the present invention. will be.

division Normal roll width (mm)
(Comparative Example) Adjustable roll width (mm)
(Example) Roughing Mill (BDM) Leader 120.0 130.0


Continuous Mill Rolling Mill
(CM)


1ST 125.0 135.0 2ST 125.5 133.0 3ST (EM) (125.5) (133.0) 4ST 126.0 131.5 5ST 126.5 130.5 6ST (EM) (126.5) (130.0) 7ST 127.5 129.0 8ST (EM) (127.5) (129.0) 9ST 128.5 128.5 Roll width change 1ST↗ 9ST 1ST ↘9ST

[Leader: Rough rolling, EM: Universal rolling mill]

For reference, the universal rolling mill means a four roll rolling mill consisting of a pair of horizontal rolls and a pair of vertical rolls.

Figure 1 is an embodiment of the H-shaped steel manufacturing method according to the present invention, the first continuous mill rolling state of the rough rolled rolling material is shown, Figure 2 is a schematic view of a roll applying the roll width adjustment method .

As shown in Fig. 1, when the rolled raw material 1 roughly rolled into a roughing mill having a roll width of 130 mm (a) is inserted into the first continuous mill rolling mill 3 and 5 having a roll width of 135 mm (b), As the flange portion of the rolled rolled material 1 is pressed down and the web rolling amount is increased, the increase in the flange length is suppressed.

As shown in Fig. 2, it is confirmed that the roll width W is determined in accordance with the double R application.

3 shows a flange overaging verification diagram of a rolled material using a plastic deformation analysis program [DEFORM].

As shown in Table 1 and FIG. 3, the web thickness of the roughly rolled rolled material obtained by adjusting the roll width was secured to 25 mm, which was 2 mm thicker than that of the comparative example. Changed location point. This reduced the flange deformation amount even at the same reduction ratio.

In addition, the rough rolled material increased the web reduction in the first continuous mill, thereby suppressing the increase in the flange length. As a result, in the third continuous mill, the edging amount of the flange was 36 mm and no over-aging occurred.

In addition, it is confirmed that the over-aging does not occur even when compared with the comparative example of manufacturing the H-shaped steel of the IPE140 standard in the H-shaped steel production line for IPE140.

In addition, as verified in the plastic deformation analysis program [DEFORM] of FIG. 3, it is confirmed that there is no influence on product quality because there is no excessive stress concentration even in the case of the comparative example.

Through this, it can be seen that the flange overaging can be prevented by adjusting the roll width due to the double R machining, the web thickness during the rough rolling, and the increase in the length of the flange in the first continuous mill.

It is to be understood that the invention is not limited to the disclosed embodiments, but is capable of many modifications and alterations, all of which are within the scope of the appended claims. It is self-evident.

1: Rough rolled rolled material
3,5: Upper and lower rolls of the first continuous mill (H-ROLL)

Claims (5)

When producing H-beams in H-beams production line with larger specifications than H-beams to be produced, rolling is performed by adjusting the gap between upper and lower rolls, and stable rolling is possible by preventing flange overaging. Co-rolling the rolled material by adjusting the upper and lower roll widths and increasing the reduction ratio of the flange compared to the web;
Rolling the rough-rolled rolled material to a higher rolling reduction amount of the web compared to the flange in the first continuous mill;
Adjusting the upper and lower roll width of the roughing mill,
The upper and lower rolls forming the roughing mill are adjusted by double R processing,
The double R is,
The difference between the upper R value (R1) and the lower R value (R2) based on the inflection point on the corners of the upper and lower rolls,
The lower R value (R2) is H-shaped steel manufacturing method, characterized in that larger than the upper R value (R1). delete delete delete The method according to claim 1,
The continuous mill rolling machine H-shaped steel manufacturing method characterized in that rolling the rolled material while gradually reducing the upper and lower roll width while going from the first continuous mill mill to the last continuous mill mill.

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