Hebei ChongSheng Special Steel Pipe Co.,Ltd.

The two edges of the straight seam steel tube is heated to soldering temperature, at squeezing rollers squeeze the metal grains to form a common mutual penetration, crystallization, forming a solid weld. If the pressing force is too small, the formation amount of the co-crystal is small, the strength of the weld metal decreases, the cracking force; if the extrusion pressure is excessive, the metal in a molten state is extruded seam, not only reduces the weld strength, and will generate a lot of internal and external burrs, and even cause the welding seam defects ride.

Straight seam welded steel pipe welds will have scars after welding and extrusion, needs to be cleared. Clear method is fixed on the rack cutter, pipe by rapid movement of the welding scars gelling. Pipe inside burr is generally not cleared. Now with welded φ32 × 2mm Longitudinal example, summarizes its process parameters: Strip Size: 2 × 98mm in diameter expand the bandwidth by adding a small amount of molding margin; Steel Material: Q235A; input excitation voltage: 150V excitation current: 1.5A Frequency: 50Hz; DC output voltage: 11.5kV DC Current: 4A Frequency: 120000Hz; welding speed: 50 m / min; parameter adjustment: the timely adjustment of output voltage and welding speed changes according to the welding heat. After the fixed parameters generally do not adjust.

High-frequency induction loop should be as close to squeeze roll position. If the squeeze roll farther away from the induction coil, the effective heating time is longer, wider heat affected zone, weld strength decreases; Conversely,carbon seamless steel pipe manufacturer china inadequate heating the weld edges, forming bad after extrusion. Impedance is a magnet or a group of dedicated pipe, the cross-sectional area of the resistor is typically not less than 70% of the pipe inner cross-sectional area, its role is the induction coil, the tube forming a seam edge of the magnet circuit of electromagnetic induction, generate proximity effect, eddy heat concentrated in the vicinity of the tube weld edges, so that the edge of the tube is heated to welding temperature. Used impedance dragging a wire within the tube, which is fixed to the center position should be relatively close to the center position of the squeeze roller. When turned on, due to the rapid movement of the tube, the impedance is affected by the loss due to friction between the inner wall of the tube is large, require frequent replacement.

Hebei ChongSheng Special Steel Pipe Co.,Ltd.