JPH03142001A - Manufacture of h-shaped steel having curved web - Google Patents

Abstract

PURPOSE:To manufacture the H-shaped steel of the specific sectional shape having a curved part in the central part of the web without adding an extra process by subjecting a rolled stock to the width reduction rolling of the web by a pair of vertical rolls while restraining the part near both end regions of the web part of the rolled stock by a pair of the horizontal rolls of a universal rolling mill. CONSTITUTION:The rolled stock is first rolled up to a web height H0 higher than the web height of a desired product in accordance with ordinary rolling procedures. The web 1a of the rolled stock 1 is then pinched above and below and is subjected to the width reduction rolling to reduce the web height including the flange thickness of the rolled stock 1 to H1 by the universal rolling mill having a pair of the variable width rolls varying in the contact length of the rolls with the web 1a above and below. The width reduction rolling to reduce the web height to H2... is repeated while the roll width of the horizontal rolls 2 of the universal rolling mill and the roll gap of the vertical rolls 3 are adjusted at every pass, by which the rolling is continued until the desired web height is attained.

Description

[Detailed Description of the Invention] (Industrial Application Field) Recently, when building or other structures are manufactured using H-beams, webs have been developed to allow installation of piping, wiring, wires, etc. H-beam steel with a curved part in the central region is increasingly being used. This invention aims to effectively hot-roll an H-section steel having such a special shape without increasing the number of manufacturing steps or increasing manufacturing costs.

(Prior art) In order to manufacture H@ steel with a curved part in the central region of the web, a steel plate of a predetermined thickness is bent to form a curved part with a desired radius of curvature, and then the flange is bent. A welding type that attaches the H-shaped steel, or a type that bends only the web using rolls with holes that form a predetermined shape after hot rolling the H-beam (Japanese Patent Laid-Open No. 63-256
(Refer to Publication No. 201), but in each case, in addition to requiring an extra process, it is necessary to keep a large number of rolls according to the product size, resulting in a significant increase in product cost. I was forced to.

(Problems to be Solved by the Invention) The purpose of this invention is to solve the above-mentioned problems that occur when manufacturing H-beam steel that has a special cross-sectional shape with a curved part in the central region of the web. The goal is to propose new methods that can be used.

(Means for Solving the Problems) In manufacturing an H-section steel having a curved portion in the central region of the web, the present invention provides for vertically rolling the web portion of a rolled material for H-section steel that has undergone rough rolling and intermediate rolling steps. A universal rolling mill is equipped with a pair of variable-width horizontal rolls that sandwich the web portion and have different roll contact lengths on the top and bottom, and a pair of vertical rolls that sandwich the horizontal rolls on the left and right sides and help adjust the web height. A curved web is prepared, and the width of the web is reduced at least once by a pair of vertical rolls while restraining the vicinity of both ends of the web part of the rolled material by a pair of horizontal rolls of the rolling mill. This is a method for manufacturing H-beam steel.

(Function) Figures 1(a) and 1(b) outline the process of forming a curved portion in the center area of the web during the process of manufacturing H-beam steel by hot rolling.
)(c), in this invention, first, rough rolling and intermediate rolling are performed according to the normal rolling procedure as shown in FIG. 1(a), and the web height Ho is higher than the web height of the desired product. Roll to . Next, web 1 of rolled material 1
A pair of variable-width rolls with upper and lower rollers having different roll contact lengths with respect to the web 1a (in this example, the contact length of the upper roll is 2L, and the contact length of the lower roll is 2F).
The first rolling mill is equipped with a universal rolling mill (shown as ,
As shown in Figure (b), width reduction rolling is performed with the web height of the rolled material 1 including the flange thickness being Hl. At this time, since the central region of the web is in an unrestrained state, only that region buckles and curves toward the shorter roll contact length. Next, width reduction rolling is repeated several times to further reduce the web height to H2 while adjusting the roll width of the horizontal roll 2 and the roll interval of the vertical rolls for each bus of the universal rolling mill. Continue rolling until the web height is reached. A specific example of a universal rolling mill that can be applied to this kind of rolling is the patent application No. 63-146.
Although disclosed in the specification of No. 947, it is also possible to arrange several of the above-mentioned universal rolling mills in tandem for rolling as long as the installation location of the equipment and the cost of the equipment do not increase.

In addition, in the present invention, in order to improve the dimensional accuracy of the product, the shape of the curved portion of the H-section steel that has passed through the above-mentioned universal rolling mill may be adjusted using a rolling mill with a finishing hole. In addition, when manufacturing a particularly large H-beam steel or when the width of the web is greatly reduced using the method according to the present invention, rolling is performed using multiple buses. Rolls having grooves as shown in FIGS. 2(a), (b), (c), and (d) can also be used for rolling and intermediate rolling.

(Example) In order to manufacture an H-section steel with a curved web having the cross-sectional shape and cross-sectional dimensions shown in Fig. 3, in the rough rolling/intermediate rolling process, a 400 x 300 rectangular cross-sectional material was rolled into a normal H-section steel. Rolled into 11 section steel with a web height of 330 + r + m using the rolling method, and then rolled with a universal rolling mill equipped with variable width horizontal rolls with a roll contact length of 1 + -70 mm.
The web height was reduced by a total of 30 mm in two passes with lz = 100 mm, and an H-section steel having a curved web with a web height of 300 mm and a height of the curved part of about 40 mm was rolled.

When the dimensions of the obtained H-shaped steel were investigated, all of them were within the permissible range, and it was confirmed that the present invention is extremely effective.

(Effects of the Invention) Thus, according to the present invention, when manufacturing an H-beam steel having a special cross-sectional shape in which the central region of the web is curved, there is no need to add an extra process, and the number of rolls required can be reduced. It can be suppressed as much as possible.

Furthermore, according to the present invention, rolling can be carried out while changing the roll width and roll spacing of the rolling mill on-line, so production efficiency can be advantageously improved.

[Brief explanation of the drawing]

Figures 1 (a), (b), and (C) are explanatory diagrams of the rolling procedure according to the present invention; Figures 2 (a), (b), (C), and (d) are diagrams showing the hole shape of the roll; The figure is a cross-sectional view of an FJ section steel with a curved web manufactured in an example. ■...Rolled material 2...Horizontal roll 3...
- Heavy Responsibility Roll Diagram 1 Procedures Amendment (Method) March 5, 1990

Claims (1)

[Claims] 1. In manufacturing an H-section steel having a curved portion in the central region of the web, the web portion of a rolled material for H-section steel that has undergone rough rolling and intermediate rolling processes is sandwiched between upper and lower sides, and the web portion is A universal rolling mill is equipped with a pair of variable-width horizontal rolls that have different roll contact lengths on the top and bottom, and a pair of vertical rolls that sandwich the horizontal rolls on the left and right to help adjust the web height. An H-section steel with a curved web, characterized in that the width of the web is reduced at least once by a pair of vertical rolls while restraining the vicinity of both ends of the web part of the rolled material by a pair of horizontal rolls of the machine. Production method.