SU577059A1 - Roll for longitudinal rolling of tubes - Google Patents

Description

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Ito retevne from Osits to pipe rolling production, Nreshsh: new to provisioning pipes on installations containing flocks of gfodo {& n | o & o pipes on ogfuk.

During pipe projection at 0% of the cost of supplying pipelines caused by brava pipes, p) completion of round metal and defects on the surrounding surface of pipes, (apari undercuts, EE, sunsets), svzvnshl @ with uneven contribution of Eopibras.

And the views of the Valkwustag of longitudinal rolling of the pipes, gmeyushve, about the m ogogravye wapvbry1.,

However, the same type of pipelines provide stabilization of pipe rolling without re-use of caliphs and serve as the cause of the gravity of the pipe contour, which causes a rejection of clamps during rolling of the pipe in a reduction machine.

, Valkv, in the name of the streams, are known to form a circular caliber with the release described by two radii 2.

The gauges of takhn rolls are difficult to manufacture, subject to intense local

2

wear and tear in the area adjacent to the round part of the caliber with the release and are the cause of the formation of a wave-like contour of the pipe causing

S "®Naghabopee close by their technical

In essence, the proposed invention is a roll for longitudinal rolling of pipes, containing a barrel with a stream consisting of a central part, forming an arc of a circle, and a straight line tangential to it with new parts of H.

The disadvantages of the known roll are the low pipes and the short service life of the roll 5, as well as the low degrees of deformation associated with the ejection of metal by local caliber metal and local wear of the stream surface in the outlet zone.

The chain of the invention is to increase the degree of deformation, improve the quality of the pipes and increase the service life of the roll.

This is achieved in that the lateral parts of the stream in the sections from the forming roll barrel to the tangential straight lines are connected with the tangential straight arcs of circles, whose radius is 0.2-0.8 of the radius of the central part.

The caliber outlets formed by the strands of such rolls are more closed and correspond to the natural bend of the pipe contour in the outlet zone, which prevents the metal from broadening, increases the stability of the pipe deformation in the outlets and prevents the metal from entering the gap between the rollers. As a result, the quality of the pipes is improved and there is a possibility of increasing partial deformations, which in the prototype were limited by gauge overflow. In addition, the stresses during rolling are more evenly distributed along the perimeter of the stream of such rolls, which increases the uniformity of wear of the stream and the service life of the roll.

The drawing shows the proposed roll, section (2-2 rotation of the roll) The roll contains a barrel with generator X-X and a stream consisting of a central part formed by the arc AB of a circle of radius R and bounded from the side parts of the corner JjOM of the issue. Side parts creek

are formed by straight A and Bd tangents to the arc AB, and arcs C and -G) K of circles of radius, which are adjacent to the tangents AC and BD and connect them to the X-X roll barrels. The centers of the circles of radius P are separated from the rim edge by an amount equal to. The magnitude of the radius P is 0.2-0.8 of the radius K. This ratio is chosen from the condition that the radius P is 2-4 times greater than the thickness of the pipe wall in the gauge issues of modern longitudinal rolling units. The surface of the vataa barrel is adjacent to the surface of a brook with an arc of radius r PrmaO-O, passing through the center of a circle of radius and parallel to the generator X-X of the roll barrel and separated from it at the distance D. At the same time, OKpyiK centers of radius p are located between the contour of the swath of the roll and the straight line O-O and are 6 degrees away from it, which lies in the interval from zero to (D +).

The manufacture of a roll can be made by boring a stream in a pattern on a roll-forming machine. Offered rolls can be installed in cages of continuous mandrel or automatic mills. The width Q of the roll brook, the radius of its central part R and the angle of release a are chosen based on the known

methods of calibration rolls tube mills.

The tube is set into rolls of a longitudinal rolling mill and crimped thereon on a mandrel. At the same time, the pipe contour section,

located in the gap between the roll barrels, is least subject to bending, since the straight, tangent k surface of the stream at the points of metal separation of the pipe from the side parts of the stream (points F and K) form with the forming X-X roll barrels angle close to 900, due to the presence of lateral sections of the stream, formed by arcs of circles of radius p, conjugate to the direction, tangent to the central part of the stream. This significantly reduces the moment arm that bends the contour of the pipe in the caliber outlets formed by rolls, and almost completely eliminates the possibility of pipe loss in the outlets and the metal escapes into the gap between the roll barrels, which in turn allows a significant increase in the degree of deformation. Since the radius P is larger than the pipe wall thickness in the outlets, the uniform deformation of the pipe in the outlet zone is increased, the inner contour of the pipe is concentric to the outer contour, and the ego eliminates the possibility of formation of cracks on the inner surface of the pipe in the outlet pipe.

The creation of a more closed gauge, formed by rolls, increases the stability of the deformation and the geometric dimensions of the rolled tubes, and also leads to a more uniform distribution of the pressures along the perimeter of the contour of the rolls. This increases the uniformity of wear of the stream surface, and therefore increases the service life of the roll and improves the quality of the surface of the pipes, which directly depends on the quality of the surface of the roll stream.

The use of the proposed roll allows to improve the quality of pipes and reduce the number of scrap, as well as to increase the mill capacity by reducing specific strain rates and shortening the transshipment time. This leads to an increase in the production of pipes of the first grade and a decrease in their cost.

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Claims (3)

1. USSR author's certificate number 357012 Cl. B 21 B 17 / GS, 1972. 2.Sb. Theory, practice and prospects for the development of the production of seamless pipes in installations with continuous mills, Yanepropetrobsk, VNITI, 1968, p. 86, 97. 3. Danilov, F. A., et al. Hot rolling and pressing of pipes. M., Metallurgists 1972, p. 44.