Thick wall pile driving mild steel pipe found in double-sided submerged arc welding production technology, product by the bending, joint, welding,straightening, flat head, such as multi-channel working procedure, achieved the American petroleum institute standard requirements. Large diameter thick wall pipe applied in large steel structure construction, do the main supporting parts, such as bridge pile, seabed piling, high-rise building pile driving. The materials general use Q345B, Q345C. Low temperature region will use Q345D Q345E.
Thick wall pile driving structural steel pipe production process:
Circular tube billet and heating to punch, three-roll skew rolling, rolling, or pressing - pipe - sizing (or reducing) - cooling - straightening to hydrostatic test or inspection tag, put in storage
Piling pipe driving carbon steel pipe manufacturing method
(1) the raw material is steel strip coil, wire, flux. Have to pass strict physical and chemical inspection before investment.
(2) the strip head to tail docking, use single or double wire submerged arc welding, after rolled steel tube adopts automatic submerged arc welding repair welding.
(3) before shaping, strip after flattening, cutting edge, edge planing, transmission and cleaning the surface to the flanging process.
(4) on both sides of the electric contact pressure gauge control conveyor under the pressure of oil cylinder pressure, ensure the smooth delivery of strip steel.
(5) the use of external control or internal control roll forming.
(6) the weld gap control device to ensure that meet the requirements of welding seam clearance, pipe diameter, and quantity of the wrong side of weld gap are tightly controlled.
(7) welding and welding are used within the United States Lincoln welding machine for single or double wire submerged arc welding, to obtain the stable welding specification.
(8) after welded pipe the weld passes the online continuous ultrasonic automatic meter check, ensure the spiral weld nondestructive testing coverage of 100%. If there are defects, automatic alarm and spray tags, production workers to adjust process parameters, in a timely manner to eliminate defects.
(9) by air plasma cutting machine to cut the welded steel pipe into single.
Cut into single pole
(10), after each batch of steel pipe in the first three root must carry on the strict inspection system, check the weld mechanical properties, chemical composition, amalgamation, steel tube surface quality and the nondestructive flaw detection, ensure that qualified pipe process, can be formally put into production.
(11) have continuous acoustic detection of weld mark parts, after manual ultrasonic and X-ray check, if there are defects, after repair, again through the nondestructive inspection, until defects have been eliminated.
(12) strip steel butt weld and fellowship with spiral weld d joint in the tube, all pass X-ray films and television inspection.
(13) each mild steel pipe after hydrostatic pressure test, radial sealing for the pressure. Test pressure and time are controlled strictly by steel pipe hydraulic microcomputer testing device. The parameters automatically printed out.
(14) pipe end machining, make the end verticality, slope Angle and the blunt edge to get accurate control.
