JPH03216201A - Hot rolling method for material to be formed with flanged section - Google Patents

Abstract

PURPOSE:To enable the remarkable change of web height by rolling with a finish universal mill after forming a material to be rolled in the rolling process before the finish rolling so as to be made into the shape of fillet part that is decided so as to satisfy a specified relation. CONSTITUTION:The shape of fillet part of the material to be rolled before the finish rolling is decided so as to satisfy the relationship of the formula. The material is formed into the decided shape of fillet part by the rolling before the finish rolling. After that, it is rolled with the finish universal mill. In the formula, ldw shows the projected contact length between the web surface of the material and the horizontal roll in the finish rolling and ldt shows the projected contact length between the outside of flange part of the material to be rolled and vertical rolls in the finish rolling. In this way, the material to be formed with flanged section can be not rolled while restraining deviation from the prescribed dimensional allowance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for hot rolling a section having a flange, such as an H section steel or a channel steel used in fields such as construction and civil engineering. It is. (Prior art) Most of the steel sections with parallel flanges (hereinafter collectively referred to as "parallel flange section steels"), such as H-section steel and parallel flange channel steel, have conventionally been manufactured by the rolling method. ,
The names of each part of these parallel flange steel sections are shown in Figure 17 (
A) and Φ) are explained using representative examples of H-beam steel and parallel flange channel steel. As shown in the figure, the flanges 10, 10 which are parallel to each other are connected and integrated by a joint l2. In the case of the H-shaped steel shown in FIG. 17(a), the joint portion 12 is located at the center of the flange portion 10, and in the case of the channel steel shown in FIGS. This joint 12 is also referred to as webHJ in the case of H-shaped steel and flange channel steel.
The length of each flange portion 10 is defined as the flange width (flange width).
length, L+), and the distance between the parallel flange parts is the web height (H.), and as shown in the figure, the inside flange method (S0) and the web inside width. ), according to JIS regulations, in the case of H-section steel, the web height (H6) is 100 m at intervals of 25 to 100 m.
Approximately 33 sizes are defined in the range of ~900 rats.

However, for example, in the case of H-beam steel, the conventional rolling method has the following problems.

That is, the conventional H-shaped steel rolling method is the same for channel steel, but as shown in FIG. Universal coarse mill group 26
This has been carried out by intermediate rolling using a universal finishing mill 28, and finishing rolling using a universal finishing mill 28. In rough rolling, rolled materials such as heated steel ingots and continuously cast slabs are rolled and formed into beam blanks through the two holes of the breakdown mill 20, which is a double reversible rough rolling mill.
Use it as a modeling material.

In the subsequent intermediate rolling, the shaping material is first rolled in a universal rough mill group 26 consisting of a universal rough mill 22 and a double edger mill 24 to form an intermediate rolled H-section steel. That is, first, as shown in the schematic side view of FIG.
The web thickness of the intermediate rolled H section steel 3l is reduced by 0, and the flange thickness is reduced by the side surfaces of the horizontal rolls 30 and the vertical rolls 32, and the above-mentioned shaping material is elongated into the intermediate rolled H section steel in multiple passes. I do. In each bath at this stage of intermediate rolling, as shown in the schematic side view of FIG. (L.) is a predetermined value.

In finish rolling, as shown in FIG. 21, the thickness of the web 56 and flange 58 is reduced in one pass or in multiple passes by the horizontal roll 52 and vertical roll 54 of the universal finishing mill 50, as in the case of the universal rough mill 22. In addition, the outer surface of the flange is made flat, and the angle between the flange 58 and the web 56 is made a right angle.

In this way, in the conventional rolling method, even in finish rolling, the inner surface of the flange 58 is pressed against the side surface of the horizontal roll 52, similar to the universal rough mill for intermediate rolling.
The outer surface of each is rolled down using vertical rolls 54. Of course, web rolling by the horizontal rolls 52 is performed in the same manner. Therefore, the inner width (10) of the H-section steel to be rolled is determined by the width of the horizontal rolls 52 of the universal finishing mill.

Therefore, due to this, the problems shown in (1) to (4) arise in the conventional method of rolling 11 section steel. (1) Figure 22 shows one series of H-shaped steel 60 with the same flange width (L0) (for example, H 600x20
0) will be explained. According to the current standards, the web inner width (-.) is constant for the same series, so the flange thickness ([f0, LL, tft) will differ, and the web height (-.) will differ for each size.
The external dimensions of H0) (H., H+, Hz in Fig. 22) also have different tonal values. That is, tf++<tft
<tft, H0<H, <H.

Such a relationship is also expressed by the groove jml70 shown in FIG.
The same applies even if

(2) When rolling steel sections with different internal widths (circles), it is necessary to replace the horizontal rolls of the universal finishing mill. For example, there are 33 series of H-beams in the JIS standard and 14 series in the STM standard, and to manufacture all of these H-beams, it is necessary to maintain the spine of at least 2&ll of 47 types of horizontal rolls. The roll costs required for this amount to reach hundreds of millions of yen even at current prices, and in order to keep these rolls in stock at all times, a large space comparable to a rolling building is required, so a large investment is also required in the roll ship building. ．． (3) The horizontal rolls of the same universal finishing mill can only roll one series of H-beams 2000 mm/rolling chance x 3 times = 6000 mm. This is because the width of the horizontal roll is worn out by about 1 m per 1000 tons of rolling, and the usable width of the roll is 6-mm even if tolerances are used effectively. Therefore, when a horizontal roll can no longer be used in a certain series, its width is cut several dozen times, and the roll is revised for the next series with a smaller web height. Therefore, compared to rolls for steel plates, the amount of product rolled per roll is significantly smaller. In other words, the roll cost per ton of product is increasing.

(4) If the web height (He) is outside the standard, it is necessary to prepare horizontal rolls for a dedicated universal finishing mill and change the rolls, so it is not economically viable for orders with small lofts. , often declines orders. (Problem to be solved by the invention)

Claims (2)

[Claims] (1) A method for hot rolling a section having a flange through breakdown rolling, rough universal rolling, edger rolling, and finish rolling, in which the rolled material after edger rolling is finished using horizontal rolls of a fixed width. When rolling with a universal mill, the inner surface of the flange does not come into contact with the side surface of the horizontal roll of the finishing universal mill, and by rolling down the outer surface of the flange with a vertical roll, 1
In a method of rolling to reduce the web height in a pass or multiple passes, the shape of the fillet portion of the rolled material before the finish rolling is determined so as to satisfy the following relationship, and the shape of the fillet portion determined in this way and A method for hot rolling a shaped material having a flange, characterized in that the shape is formed in a rolling step before the finishing rolling so that the shaped material is rolled in the finishing universal mill. l_d_w≧l_d_f Here, l_d_w is the projected contact length between the web surface of the rolled material in the finish rolling and the finishing universal mill horizontal roll, and l_d_f is the projected contact length between the outer surface of the flange part of the rolled material in the finish rolling and the finishing universal mill horizontal roll. Each represents the projected contact length with the universal mill vertical roll. (2) A method for hot rolling a profile with a flange through breakdown rolling, rough universal rolling, edger rolling, and finishing rolling, in which the horizontal roll width of the finishing universal mill is divided into two, and the width can be adjusted online. In the method of reducing the web height by one pass or multiple passes of reverse rolling in the finishing universal mill, the shape of the fillet part of the rolled material before finishing rolling is determined so as to satisfy the following relationship: The shape having a flange is characterized in that the shape is formed in a rolling step before the finish rolling so as to have the fillet shape determined in this way, and then rolled with a finish universal mill consisting of the two-divided horizontal rolls. Method of hot rolling material. l_d_w≧l_d_f Here, l_d_w is the projected contact length between the web surface of the rolled material in the finishing rolling and the finishing universal mill horizontal roll, and l_d_f is the projected contact length between the outer surface of the flange part of the rolling material in the finishing rolling and the finishing universal mill. Each represents the projected contact length with the mill vertical roll.