The formation of weld burr and clear:

By high frequency current skin effect and proximity effect, current concentration in the weld heated to a molten state, the lateral extrusion roller pressure welding, the extrusion pressure, excess metal and oxide accumulation in the upper seam surface burr formation; Affected by extrusion and the joint action of gravity and some extra metal and oxide along the tube axis direction within the burr in the medial droop.

Burr width at around 0.5 ~ 3 ㎜, usually within the burr height is uneven, the general is 0.2 ~ 0.6 ㎜. Individual height can reach more than 1 ㎜. Outside burr planing method is commonly used in clearing and inside burr in steel pipe inside the space is little, clear technical difficulty is increased. Because of the existence of burr inside when cold drawn or cold rolled steel pipe again finishing, will be formed in the steel pipe inner surface crack, collapse or scratches. So for precision welded pipe, don't remove the burr cannot reach the inner surface quality requirement, also can't be hind leg's machining.

Outside burr removal system have a cutter and the cutter type, use a cutter for machine knives, and the cutter with two deburring, tool change don't need to stop.

Remove the burr technology is difficult, due to the burr of the special-purpose device inside the steel tube, working environment is very poor, can't see, touch less than, it is the strip forming process of precision and accuracy of the equipment, and the weld shape, often not guaranteed. Data reported abroad, inner hole above 14 ㎜ welded pipe can be remove the burr, actually inner hole under 25 ㎜ within the burr removal is difficult. Domestic technology generally, pore over 50 ㎜ large diameter welded steel pipe can be remove the burr.

Remove the burr, usually in continuous welded pipe production line, can also be used offline methods to remove.

Remove burrs in methods, mainly has the following several ways:

Cutting method: this method is to use fixed or rotating blade, the cutting head into the tube for cutting burr.

Rolling method: this method is used in tube rolling device, make the inside burr produces plastic deformation, the effect of thinning inside burr height.

Oxidation method: at the start of the steel pipe welding, oxygen to inside weld with airway nozzle jet flow, the use of weld seam welding heat, make inside burr accelerated oxidation, and under the air rushed out of the loss.

Drawing method: steel pipe through the mould, under the influence of floating plug circular blade, remove burrs in steel pipe.