High Quality Forming and Sizing Roller

All molds are made of high-quality mold steel materials.
Processed by high-precision CNC equipment and subjected to special heat treatment.
The mold has high precision, reliable quality, and long service life.
From the perspective of welding process, the welding method of spiral welded pipe is the same as that of straight seam steel pipe, but the straight seam welded pipe will inevitably have many T-welds, so the probability of welding defect is greatly increased. Moreover, the welding residual stress at the T-weld is large, and the weld metal is often in a three-way stress state, increasing the possibility of cracks.
In addition, according to the process regulations of submerged arc welding, each weld should have an arc striking position and an arc extinguishing position, but each longitudinal welded pipe cannot meet this condition when welding the circumferential seam, so there may be many welding defect at the arc extinguishing position