SU1407599A1 - Method of hot pilger rolling of tubes - Google Patents

Abstract

This invention relates to pipe production, in particular to a hot pilgrim method without pilger head. The goal is to reduce the mass of trimming. The method of hot piligrim rolling of tubes involves batch rolling of the liner on the mandrel with rollers having idle, crimping and calibrating sections before obtaining a pipe with an equal-length socket at the end equal to the wall thickness of the finished pipe. After rolling the liner, the mandrel is partially pulled out of the tube and the bell is pushed through the crimping rolls. Then a portion expansion of the bell is carried out with calibrating rolls. with (5 (L

Description

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The invention relates to pipe production, namely to the method of hot pilgrim rolling without pilger head.

; The purpose of the invention is to reduce the mass of ebresi.

Pilgrim pipe rolling method includes portion rolling of the liner on the mandrel with alcoves, having idle, crimping and alibing sections, until the pipe is made with an equal thickness socket at the end equal to the wall thickness of the finished pipe. After the ascate of the liner, the mandrel is partially pulled out of the pipe and the gun is pushed through the crimping rolls. Next, batch rolling of the astrub is carried out with calibrating rolls. When | pushing a .strub through the crimping areas of the rolls, it is reduced to a diameter | This means that it excludes the possibility of displacing the pipe relative to the road during the pushing period and reduces the repair time to a minimum.

The subsequent processing of the reduced bell by rolling with calibrating rolls achieves polishing the pipe in diameter and then. wall ptsina.

T Example The application of the proposed method is most effective in the production of large diameter pipes (325-425 mm) from alloyed steel grades obtained by the method of continuous and semi-continuous casting. As an example, a method for producing pipes with a size of 425 X 7.5 mm from 38X steel is given.

The original billet — a sleeve with a size of 600 X 50 mm and a temperature of 105b ° C — was deformed until the socket was struck with pilger rolls on the mandrel with a diameter of 410 mm, with an emphasis on the back end. The role of the stop was performed by the retaining ring, profiled from the side of the liner according to the scanning of the crimping section of the pilger rollers. The minimum diameter of the ring is 410 mm, the maximum is 500 mm. After that, from the rolled pipe into the Mdrgivali mandrel. In the annular recess of the thrust ring, a spike in the pilgerstan and | The feeder was fed back. The pull out value corresponded to the rolls of the pinch of the feeder and was 1.6 m.

The next stage of rolling was the processing of the socket, while the ring was also fixed with a hook. To do this, at the time when the blooming sections of the rolls came out, the vertical axis of their centers was pushed by the feeder with the mill apparatus.

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together with a rolled pipe with a bell through the gauge of the rolls. The pushing stroke depended on the socket length and was 500 mm. After pushing the socket in this area, the outer diameter is 425 mm, thickness is 7.5 m. Pushing duration 1–2 s. Pushing the bell can also be carried out with non-threading rollers. To do this, at the approach of the ends of the crimping sections of the rolls to the line of their centers, the rolls were stopped, and pushing the pulses. Do this way.

Finally, the treatment of the socket after pushing it was done by rolling, using the straight swaths of the rolls. To do this, at the moment of approaching these sections to the line of the centers of the rolls by a certain amount (feed tag), the bell section was fed to the rolls (feed rate 50 mm). Calibrating roll areas captured the surface irregularities of the bell section and with further rotation of the rolls they were rolled out as with a regular pilger roll.

Thus, for each revolution of the rolls, the pitches of the spike in the caliber were squeezed to the caliber, and a smooth pipe with a diameter of 425 mm and a wall of 7.5 mm was obtained. When processing the socket, the whole process was stable and stable; no displacement of the pipe relative to the mandrel was observed. The quality of the surface and the dimensions of the machined socket corresponded to the quality and dimensions of the pipe obtained by rolling the core of the liner.

Thus, the use of the proposed method makes it possible to reduce process waste during hot piligrim-rolling of pipes, cutting up to a minimum, to conduct rolling steadily and stably, to process the socket almost without reducing the mill's productivity.

Claims (1)

Invention Formula The method of hot piligrim rolling of pipes, including batch rolling of the liner on the mandrel with rollers having idle, crimping and calibrating sections before obtaining a pipe with an equal thickness flare at the end equal to the wall thickness of the finished pipe, characterized in that Rolling the mandrel is partially pulled out of the pipe, pushing the bell through the crimping sections of the rolls, and then carrying out portioning of the bell by calibrating the rolls.