JPH0275404A - Roll for drafting web thickness of shape stock - Google Patents

Abstract

PURPOSE:To prevent shape defects in a web part of a shape stock and to improve the yield by imparting a reverse roll crown preventing thickness increase in web edge zones of a shape stock to a roll. CONSTITUTION:A roll body 2 is provided with a reverse roll crown bringing a crown amount to be delta. A web part of a shape stock with the web is drafted in its thickness direction by the roll to prevent thickness increase in web edge zones. Hence, shape defects in the web of the stock are prevented to improve the yield.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a method for manufacturing H-shaped, channel-shaped or similar steel sections, especially during the period from the rough universal rolling stage to the finish universal rolling stage. The present invention relates to a rolling roll suitable for use.

(Prior art) In the production of shaped steel, the web of the shaped steel is rolled during the rolling process in order to freely adjust the web height without requiring frequent roll replacement or to improve the dimensional accuracy of the product. A rolling method is used in which the material is rolled down repeatedly in the width and thickness directions to achieve the desired size, and the rolls used to roll down the web of the shape in the thickness direction are those with flat surfaces. was.

(Problem to be Solved by the Invention) By the way, in the above rolling method, when the web portion of the shape material is rolled down in the width direction, the vicinity of both ends thereof is thicker than other regions (
The web may deform and exhibit a local thickening phenomenon, and even if a normal flat roll is used to roll down the web portion in the thickness direction, it is difficult to completely eliminate the thickening tendency in that area. There were disadvantages such as deformation of the web portion, which adversely affected the cross-sectional shape of the product.

It is an object of the invention to propose a rolling roll which can advantageously eliminate the local thickening that occurs during rolling down of the web section in the width direction.

(Means for Solving the Problems) The present invention provides a roll for rolling down the web portion of a section provided with a web in the thickness direction thereof, the roll having a reverse direction that prevents thickening of the web end region of the section. This is a roll for reducing the web thickness of a shaped material, which is characterized by being provided with a roll crown.

FIG. 1 schematically shows the lower half of the web thickness reduction roll according to the invention. In the figure, number 1 is the roll axis, and number 2 is the roll body.This roll body 2 is provided with a reverse roll crown with a crown amount of δ, and the roll body 2 moves in the axial direction of the roll axis l. ,
The roll width W can be changed as appropriate.

(for production) The present invention will be explained below by taking the production of H-beam steel as an example.

Normally, when manufacturing H-beam steel by rolling, for example, the second
The equipment shown in the figure is used, and the shaped material carried out from the heating furnace is finished into the desired size by passing through the various stages shown in the figure. Here, the adjustment of the web height of H-beam steel is as follows.
Adjustments are made by rolling down the web portion of the profile by a predetermined amount in the width direction, for example, as shown in FIG. 3, in one pass from the rough universal mill group to the finishing universal mill group.

By the way, in this case, until the web part of the profile comes into contact with the web thickness reduction roll H, the temperature is locally high in the web end region, that is, near the R part (in the range of about 30 to 50 mm from the end), where the temperature is relatively high. This tendency to increase in thickness was difficult to overcome even if the web portion of the profile was rolled down in the thickness direction in the subsequent rolling process. The increase or decrease in web thickness in this region depends on the temperature distribution of the profile, and as shown in FIG. 4, the tendency is greater for thinner webs.

Therefore, in this invention, both sides of the web thickness reduction roll for rolling down the web portion of the profile in the thickness direction are
A reverse roll crown is provided in the mn+ range, and the increase in web thickness is extended in the longitudinal direction to smooth the web surface.

Although FIG. 1 above shows a variable width roll as an example, the roll width may be changed, but it may be an integral roll as shown in FIG. 5, for example.

(Example) The results of measuring the increase in web thickness at each point in the width direction of the H-section steel finished after rolling with the web thickness reduction roll shown in Fig. The results are shown in Figure 6.

It was confirmed that when the web part of the profile was rolled down in the width direction and then rolled down using a roll provided with an inverted roll crown, the web thickness was almost constant in the width direction.

(Effects of the Invention) According to the present invention, local damage to the web portion, which is difficult to avoid in the rolling method in which the web height of the section steel is adjusted by rolling down the web portion of the section in the width direction, is achieved. Yield can be improved by preventing shape defects caused by increased thickness.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a roll for reducing the web thickness according to the present invention, Fig. 2 is a diagram showing the layout of equipment for manufacturing H-section steel, Fig. 3 is a diagram showing the steps for rolling down the web in the width direction, Fig. 4 is a graph showing the relationship between the increase in web thickness and the amount of reduction in the web width direction, FIG. 5 is a diagram showing another example of the present invention, and FIG. 6 is a diagram showing the results of measuring the amount of increase in web thickness. be. 1... Roll shaft 2... Roll body W...
・Roll width

Claims (1)

[Claims] 1. A roll that rolls down the web portion of a section having a web in its thickness direction, the roll having an inverted roll crown that prevents thickening of the web end region of the section. A roll for reducing the web thickness of a shaped material.