Seamless Steel Pipe High-Frequency Welding Technique

1. Control of Weld Seam Gap

The steel strip is fed into the welding pipe unit, where it is gradually rolled up through multiple rolling rolls, forming a circular billet with an opening gap. The downward pressure of the extrusion rolls is adjusted to control the weld gap between 1~3mm, ensuring both ends of the weld are flush. If the gap is too large, the proximity effect decreases, resulting in insufficient eddy current heat and poor junction of the weld joints, leading to incomplete fusion or cracking. If the gap is too small, the proximity effect increases, excessive welding heat is generated, causing burn damage to the weld; or after extrusion and rolling, deep pits are formed, affecting the surface quality of the weld.