SU710689A1 - Pilgrim-step tube-rolling method - Google Patents

Description

shey. values that leads to a discontinuity of the metal.

The goal ieobreten: improving the quality of study of the metal.

The goal is achieved by the fact that in the pilgrim rolling method of tubes, which includes a batch feed of the workpiece with rotation when the rolls are open, the compression in a variable cross-section caliber on the mandrel with the rotation of the exit pipe during the reduction and calibration, the rotation of the pipe during the reduction is performed with a smooth decrease in angular velocity and completely stop during calibration.

FIG. 1 shows a scheme for carrying out the method at the time of opening the throat (idling); in fig. 2 is the same at the time of reduction (working stroke in FIG. 3 is a graph of the change in the angular velocity of rotation of the pipe coming out of the rolls during the reduction.

When the cage is idling, that is, when the pilgrim rolls 1 are open, the portion of the workpiece 2 is fed to the rolls by the cartridge 3 by displacing the workpiece relative to the mandrel 4, rotated with the mandrel by the cartridge 3 and the front cartridge 5 with the same angular speed. At the end of idling, the rotation of the workpiece 2 by the chuck 3 is stopped, the workpiece is gripped and squeezed by the working section of the variable profile caliber with the front chuck 5 of the tube coming out of the caliber b during rotation. At the same time, the angular speed of rotation during the reduction process smoothly decreases in proportion to the deformation and completely stops during the calibration of the workpiece / f KQAuS.

According to the proposed method, the pipes were rolled with an outer diameter O „ap 15.6 m, wall thickness 5 1.8 mm from blanks with D с 38 mm and 3 7 mm, obtained by longitudinal rolling and having as a result a pronounced longitudinal-fibrous structure. The workpiece material is 45X1 steel. Rolling was carried out at a feed rate of 1.93 mm. In this case, pipes with an isotropic internal structure in the longitudinal and transverse directions were obtained.

When rolling tubes with a longitudinal fiber structure, according to the proposed method, the longitudinal fibers are deformed by rolls, being in the state of elastic-plastic twisting. Due to this deformation method, the longitudinal fibers of the billet are destroyed and the internal structure is well developed. As a result, the angular velocity decreases. rotation of the rolled part of the pipe in proportion to compression of the longitudinal fibers in the deformation zone have a constant twist angle, which contributes to azovaniyu isotropic metal structure of the rolled tube. The pipe is calibrated without turning it, which prevents the occurrence of internal defects.

The proposed method of piligrim tube rolling allows to crush the longitudinal fiber structure of the workpiece and obtain pipes with an isotropic structure in the longitudinal and transverse direction, as well as to eliminate the formation of defects in the rolling process of pipes from the longitudinal fiber structure.

Claims (2)

1. Authors certificate of the USSR 438452, cl. B 21 B 21/00, 1973. 2. USSR author's certificate According to It 2482758, cl. B 21 B 21/0 1977. mind 1 About J / V-RL . one four-// reviews e cal.