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.

Causes of burrs and edge warping:

(1) The slitting blade of slitting is not sharp.

(2) The precision of the slitter knife shaft is poor, or there are impurities on the spacer plane, which causes the slitting knife plane to swing on the knife shaft, which affects the side clearance and produces periodic burrs on the edge of the tube blank.

(3) The gap between the upper and lower edges of the slitting blade is too large.

The effect of burrs and edge warpage on the quality of welded pipes:

(1)Slight tube blank burrs and edge warping have little effect on thick-walled tubes and standard-walled tubes: for some tubes that require smaller internal burrs and extremely small tubes, you can also reverse the tube blank The feeding method achieves the purpose.

(2) When the edge is warped severely, a "corner joint" will be formed, that is, the outer edge corner joint shown in Figure A will appear when the A side is rolled on the outside, and the outer edge corner joint shown in Figure A will appear when the A side is rolled to the inside. The inner edge of the corner joint, the two edge butt forms are undesirable for the welding process.

(3)The external burrs of thin-walled tubes are difficult to remove. Tube blanks with large edge burrs and warped edges should be avoided as much as possible in the production of thin-walled tubes.

About the used high frequency tube mills welded tube defects (5) introduction of burrs and edge warping, and the impact of burrs and edge warping on the quality of welded pipes, I hope it can help you.