SU829254A1 - Method of straightening crescent-shape of rolled strip - Google Patents

Description

one

The invention relates to methods for continuous straightening by plastic shaping of long-length rolled strip, mainly the seridity of coil steel.

Closest to the present invention is the method of straightening the crescent of the bands by plastic stretching. According to this method, in order to improve the quality of the straightening and to save materials, the straightening is carried out sequentially in sections, while prior to stretching the strip at the beginning and end of the straightened section is clamped with simultaneous straightening at its side edges 1.

The disadvantage of this method is the necessity of clamping the strip along the concogil of the straightened region. .

To ensure the required quality of editing to the methods of clamping the strip and to the devices for. Their implementation has the following requirements. First of all, the strip in places of clamping should not be damaged. In addition, in order to ensure the quality of the adjustment, in terms of the accuracy of crescent correcting, the clamps should be able to rotate in the plane of the strip without slipping.

However, the fulfillment of these requirements will lead to a serious complication of the clamping devices, which will reduce the reliability of the clamps, aetr, in turn, will negatively affect the quality of the crescent correction.

The purpose of the invention is to improve the quality of edits.

The goal is achieved by

0 that the strip is wound successively in sections along a helical spiral on the working rail of the expander with a constant spacing between turns, and plastic stretching is performed by

5 distributions by the expander of the wound section of the strip and simultaneous front and rear tension of the entire strip.

FIG. 1 shows schematically wound on the expander turns of the crescent strip before editing; in fig. 2 - also | after distribution by an expander (arrows indicate the direction of tension of the strip).

The method is as follows.

5 way.

When unrolling the feed roll 2, the strip of steel coil 1 is wound in a helical spiral around the working part 3 of the expander 4, for example, of a hydromechanical design, with a constant pitch t between the turns, and then folded back into the take-up roll 5. the rear tension of the strip in the direction indicated by the arrows after what is done is the distribution of the turns by the expander, i.e. plastic stretching of the strip in the area equal to the total length of the coils. Spreading or plastic stretching is carried out on a size sufficient to eliminate the taper of the turns due to the crescent of the strip and give the turns a residual cylindrical shape. This ensures complete elimination of not only sickle-shaped areas, but also waviness of edges and other deviations from the plane. After straightening, the strip is removed, the working part of the expander is reset, and the corrected portion is replaced with a new one by unwinding the feed roll and winding the take-up rolls, for example, while rotating. the expander around its longitudinal axis. Then, all operations are repeated.

The method is tested in the PEC on laboratory equipment. For the study, a strip was taken from st. Z, with a cross section of 1.5 x 600 mm, 2.5 m long, with an initial crescent of 10 mm on the base of 10 m. The strip is wound in a helical spiral (two turns) around the working part of the hydraulic an expander, which is a vessel, working under pressure, with an outer diameter of 400 mm, with elastic walls. The ends of the strip are tightened with a force of about 2 kg / mm and are clamped. The gap between the turns is constant and equal to 5 mm. Because of the crescent shape of the strip, the coils are conic, which is eliminated by increasing the diameter of the expander as a result of an increase in pressure in its working cavity. During the distribution process, the extent of stretching of the strip along its width is monitored. When the residual cylindrical shape of the coils is obtained, the stretching is over. the width of the strip is: at the concave edge, 0.22%, and at the convex edge, 0, 27%. Residual sickle is practically absent.

The use of the proposed method makes it possible to efficiently produce continuous straightening of the crescent of stainless steel. Nowadays, due to the crescent shape, the widespread use of such a progressive type of rolled products such as coiled steel is inhibited. The corkscrewing complicates the technology of welding spiral-welded pipes due to the formation of a variable gap in the joint or over-edges, complicates the operation of winding multi-layer shells in the manufacture of high-pressure vessels and pipes, and also virtually eliminates the possibility of mass production of welded panels of rolled steel welding strips along the longitudinal edges. The proposed method of continuous straightening of crescent eliminates the main shortcoming of coiled steel steel, its crescentness, which opens up wide possibilities for using this type of rolled steel in the manufacture of many new welded structures and to improve the quality of products already manufactured.

from rolled steel.

The economic effect of using rolled steel instead of sheet steel in the manufacture of panels for tanks with a capacity of up to 1000 m will be 60 thousand rubles. per year in one installation with an annual capacity of 6000 tons of panels.

Claims (1)

1. USSR author's certificate 410849, cl. B 21 D 25/00, 1971. fa1-1