Weld treatment of LSAW steel pipe

    LSAW steel pipe is the strip into the pipe unit, the multi-roll rolling, strip gradually rolled up to form a circular gap open billet, adjust the squeeze roll reduction, so that weld gap control In the 1 ~ 3mm, and make both ends of the welding flush. If the gap is too large, it will reduce the proximity effect, eddy current heat shortage, weld intergranular bonding caused by poor fusion or cracking. Such as between

    If the gap is too small, the proximity effect will be increased, the welding heat will be too large, and the weld will be burned; or the weld will be crushed and crushed to form the pit, which will affect the weld surface quality.

    Welding process example:

    Weld φ32 × 2mm longitudinal welded pipe, for example, briefly describes the process parameters:

    Strip specifications: 2 × 98mm bandwidth by medium diameter expansion plus a small amount of molding margin.

    Steel material: Q235A

    Input excitation voltage: 150V Excitation current: 1.5A Frequency: 50Hz.

    Output DC voltage: 11.5kV DC current: 4A Frequency: 120000Hz.

    Welding speed: 50 m / min.

    Parameter adjustment: according to the welding line energy changes in time to adjust the output voltage and welding speed. Fixed parameters generally do not have to adjust.