SU1276383A1 - Method of rolling billets - Google Patents

Abstract

The invention relates to rolling production and can be applied for twisting and turning a roll between gaps in the cages of a continuous mill. The purpose of the invention is to simplify the implementation of the roll twisting operation and the mill equipment used for this. According to the invention, an inclined arrangement of gauges in the rolls is provided, due to which the roll out of the rolls is already in a twisted state and does not require special additional means and operations for rolling the roll between the stands. 3 ill., 1 tab.

Description

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The invention relates to rolling production and can be applied for rolling-edge roll between gaps in the cages of a continuous mill.

The purpose of the invention is to simplify the implementation of the roll twisting operation and the mill equipment used for this.

FIG. 1 shows a pattern of twisting roll; in fig. 2 - inclined caliber with a roll and a scheme of action on rolling out rolling forces; in fig. 3 - scheme of action on the roll of tangential forces.

The method is implemented as follows.

During rolling of roll 1 (Fig. 1) in a caliber formed by horizontal rollers 2 and 3 (Fig. 2), forming which are made along the bottom of the gauge at an angle, opposite pairs of forces appear, contributing to the strip twisting around the longitudinal axis X (Fig. 1 and 2).

The resultant normal forces PH and PB (Fig. 2) are equal in magnitude, but do not pass through the center of gravity of the section, therefore they create a moment twisting the roll counterclockwise.

In addition, due to different peripheral velocities, friction forces act on the contact surfaces, contributing to the twisting of the roll counterclockwise (Fig. 3), and these forces create a moment acting at the exit from the deformation zone. Active friction forces (m. - have a positive sign and are directed towards the movement of the roll) arise in those areas of the contact surface that are created by a large roll diameter.

The angle of inclination of the forming rolls, which ensures rolling of the rolled stock at a given angle (45 or 90 °), on a length L equal to the distance between the axes of the rolls of adjacent stands, is determined by an empirical formula derived from the processing of experimental data on rolling conditions modeling and canting on continuously preparing mills

99 fc-h

G 1 LjRAh

where 1.8, ..., 2,2 is a coefficient depending on the mechanical properties of the metal, its temperature, friction conditions; with - the side of hire minimum on the geometrical sizes; h - thickness of rolled stock

from the cage;

Ah - absolute compression in the cage; R - average rolling radius

roll.

When switching to a different size of rolling, the roll stand with rollers is moved along the axis of the rolls until the required gauge coincides with the rolling axis.

Example. As an example, consider the rolling process in the NZS 900/700/500 draft group, starting with 4 stands. After the 4th stand, the direction of reduction changes in each subsequent one by an angle equal to l / 2. The distance between the stands is 5500 mm, steel 45, temperature 1100 ° C. Calibration of rolled products and the required angle of inclination of the forming streams of caliber J, determined by the formula with the coefficient of deformation conditions equal to 2, are given in the table.

330

200

230 220

220 165 250 165 178 185 178 139 196 139

The effect of using the proposed method is to simplify the construction of the rolling stand, as well as to avoid reconfiguration when switching from one rolled-up size to another.

6 22

390 6 48 310/02 300 5 ° 22 300

Claims (1)

The invention The method of rolling billets, mainly in continuous groups of stands, including the formation of roll in caliber rolling rolls at least two