Problems that will occur in fine boring rolling tube

- May 14, 2020-

Precision boring rolling pipes are widely used in industry, but problems often occur in the production process. In order to produce good products, we should pay attention to some problems that are easy to occur in production, reduce defective products, and save costs. The following problems often occur in the production process of precision boring rolling pipes:

Horizontal scratches on the tube surface: Horizontal scratches on the tube surface are usually due to non-sliding or edge wear of the roll opening, and when the groove or roller does not leave the tube, the steel tube is fed back.

Longitudinal scratches on the surface of the tube: Usually the roller hole is too small to rotate, the roller is dragged on the surface of the tube, the slope of the slide plate section is not enough, the selected roller is too small or the tube blank is too large.

Nozzle cracking: the radial tension exceeds the strength of the rolled tube; there are micro cracks at the end of the tube, and the cracks expand during the rolling process; the roll opening is too large to produce lateral tension, and the cracking occurs when the tensile stress exceeds the tensile strength; The thickness of the pipe wall is severely uneven, and large deformation causes cracking.

Pipe cutting into the head: generally due to improper adjustment of the swing rod, which generates a large axial force; when rolling a thin-walled pipe, the outer diameter of the mandrel is too large; the end face of the pipe is not flat, and the pressure is too large. The mandrel is not too difficult to stick to metal or mandrel, so it is not synchronized with the tube blank.

Intermediate cracking: Generally, the billet is not conveyed during rolling, and is rolled in situ. The two mandrels are not tightly connected and unevenly connected to form a hollow rolling. The original crack in the middle of the tube expands in the middle.