Spiral tube heat treatment process

Spiral steel pipe into the steel unit, multi-roll rolling strip gradually rolled up, and the formation of a gap with the open tube, squeeze roll to reduce the adjustment, weld gap control in 1 ~ 3mm, the weld flat.


1. If the gap is too large, resulting in reduced proximity effect, lack of eddy current, poor weld crystallization, indirect fusion or cracking bad.


2. The gap is too small, resulting in increased proximity effect, excessive welding heat, causing the weld to rupture; weld or extrusion, the formation of pit after rolling, affecting the weld surface quality.


After heating at both ends of the tube, the welding temperature is squeezed by the squeezing roller, the common metal particles of the spiral tube penetrate each other and crystallize, finally forming a solid weld. If the spiral tube extrusion pressure is too small, the formation of a small number of eutectic, the stress reduction of weld metal strength will produce cracking; if the pressure is too large, will make the molten metal is squeezed out of the weld, not only reduces the weld strength , But also produce a lot of internal and external burr, and even cause defects such as welding seam.