Defects on the inner surface of hot rolled seamless tubes

Inner folding plate: Straight, spiral or semi-spiral serrated defects appear on the inner surface of the steel pipe.

Internal scars: The scars on the inner surface of the steel pipe are generally easy to peel off.

Warping: Straight or intermittent small spike-like inclined leather. Common in capillary head, and easy to peel.

Straight inside: Straight scratches with a certain width and depth.

Inner edge: a straight-shaped protrusion with a certain width and depth.

Inner drum kit: Super regular bumps and outer surface are not damaged.

Pulling pits: regular or irregular pits, the outer surface of which is not damaged.

Internal thread: Spiral marks are often seen on the surface of thin-walled tubes, and there is a noticeable unevenness.