If the used high frequency tube mills refers to the chemical composition and mechanical properties of welded tube blanks that require certain inspection methods to be known as invisible defects; then, those defects that can be seen only by vision are called tube blanks. Overt defect.

The dominant defects of the welded tube blank of the used high frequency tube mills generally include cracked edges, broken edges, sawtooth, pitting, scratches, roll marks, dark spots, edge burrs, sickle bends, wrinkles, waves, edge warping, and points. Layers, warped skins, pinholes, sticky rolls, soft spots, rust, oxide layers, towers, loose rolls, etc. Let me introduce you to the causes of cracked edges and the effect of cracked edge billets on welded pipes.

Scratches

Scratches refer to the scratch marks that exist on the surface of the tube blank. The characteristics of scratches are mostly longitudinal and relatively fixed in position, with certain rules to follow.

Causes of scratches:

(1) During cold rolling, hard foreign matter entered the tension plate of the rolling mill and scratched the surface of the tube.

(2) Hard foreign matter invaded and scratched in the splint of the slitting tension station.

(3) The driving roller does not rotate flexibly and scratches the surface of the welded pipe during storage.

(4) The scratches on the outer ring of the blank are mainly caused by accidental rubbing during storage, hoisting and transportation.

The effect of scratches on the quality of welded pipe:

The effect of pitting on the quality of welded pipe is similar to that of pitting.

About the used high frequency tube mills welded pipe blank defect (4) Scratch introduction, and the impact of the scratch on the quality of the welded pipe, I hope it can help you.