SU1463358A1 - Method of rolling blooms - Google Patents

Abstract

The invention relates to rolling production and can be used in the rolling of ingots on sizing mills, in particular on blooming. The aim of the invention is to increase the yield by reducing the weft of both ends of the roll. The method of rolling blkmov involves successive compression of the metal roll with roll backs and with the same compression in a series of successive passes. Rolling with the same absolute reductions is carried out with free winding in the first passes to a roll height equal to 0.49-0.43 of the initial thickness, and rolling in gauges is done with a consistent increase in absolute reductions in each successive pass. 2 tab. but ; (L

Description

one

 The invention relates to rolling production and can be used in the rolling of ingots on compression mills, in particular on blooming.

The aim of the invention is to increase the yield by reducing the weighting of both ends of the roll.

The goal is achieved by the fact that rolling with the same absolute reductions is carried out with free broadening in the first passes to the height of a roll equal to 0.49-0.43 of the initial thickness, and rolling in gauges is carried out with a consistent increase in absolute reductions in each successive pass.

Rolling the ingot with the same absolute cuts with free recovery to the height of the roll, equal to 0.49-0.43 of the initial thickness of the ingot, allows you to consistently increase. . The intensity of the development of the central layers is proportional to the increase in relative reductions, which leads to a corresponding increase in the stretching of these layers. In addition, the difference in and .th of the central and surface layers (weft) is partially compensated by the free expansion of the latter.

The expediency of sequential increase in absolute reductions during subsequent rolling in calibres of definite O) 00 CO el 00

This is due to the fact that in this case the stretching of the central layers increases exponentially and, by the end of rolling, approaches the amount of drawdown of the surface elbows, the compensation accumulated in the first passes of the weighting.

Example. Ingots weighing 8.2 t with a cross section of 830 730/770 690 mm roll bloom with cross-section

,

ten

with a nominal section of 280 "330 mm and mm. In accordance with the pre-rolling method of rolling, the regimes of reduction of the indicated ingots on the blooming 1250 have been developed.

The mode of crimping blooms with a section of 280 "330 mm from ingots of low-alloyed steel weighing 8.2 tons is shown in Table. one.

In the first passes, the magnitude of absolute reduction is the same (90 mm) with a 40 constant increase in relative reductions. When the ingot taper is removed, their average value is indicated in the first and third passes. After crimping to a roll height of 360: 830 0.43 45

90 ° tilt

Table 1

the initial thickness of the ingot, absolute reduction consistently increase from 110 to 140 mm by the end of rolling.

The mode of compression of blooms with a section of 320 "340 mm from ingots of a regular carbon steel with a mass of 8,2 t is shown in Table. 2

Table 2

From tab. 2, it follows that with a constant growth of relative reductions in the first passes, rolling is carried out with the same absolute reductions (80 mm) with free running up to the height of a roll equal to 410: 830 0.49 of the original ingot thickness, and rolling calibers are carried out with sequential an increase in absolute reductions in each successive pass from 110 to 140 mm.

The results of pilot rolling according to the given modes, developed according to the proposed method, showed that the tightening length decreased by an average of 2.7 times as compared with the known rolling. Accordingly, the mass of trimming decreased by an average of 1.21 times. Thus, the average amount of trimming has decreased: for the bottom part of the roll, from 2.2 to 0.8%, for the head part (taking into account the cut of the shrinkage shell) with

Continuation of table 2

14.3 to 12.8%. At the same time, the bottom trim is reduced by 2.75 times.

Claims (1)

The proposed method of rolling blooms reduces the amount of metal needed for cutting by reducing the weighting of both ends of the roll and, accordingly, increases the yield. The invention of the method of rolling blooms, including the sequential reduction of metal rolls with the same absolute compressing in a series of successive passes with canting and rolling in a caliber, characterized in that, in order to increase the yield by reducing the weighting of the ends of the roll, rolling in the first passages is carried out with a free broadening to the height of the roll 0.49- 0.43 of the initial ingot thickness, and rolling in gauges is carried out with sequential an increase in absolute reductions in each successive pass.