Spiral submerged arc welding pipe production molding

Spiral submerged arc welded pipe production, forming and welding are carried out at the same time, so the stability of welding quality is good or bad, forming an indivisible. Forming tight when tight loose, "pouting", loose within the loose tight loose within the local error from the side shift, squeeze thick side panels, missing cutting, waves, burrs and conical irregular pores, resulting in poor and Weld undercut, burning, porosity, slag and other defects form. Therefore, we found that we must adjust the forming instability in time.


The external influence of the flux is closely related to the quality and chemical control of the weld-formed spiral submerged arc welded pipe flux, viscosity, bulk density, particle size and packing height.


The chemical composition and viscosity of the flux composition have a significant effect on the weld. Although all manufacturers flux GB / T 5293-1999 standard line, but because of its formula, its metallurgical performance and process performance are not the same. At the time of selection, we can observe, test, analyze and compare to select the best candidate. The choice of flux should ensure good metallurgical properties and process performance. Stable arc slag has suitable melting point, viscosity and surface tension, and the weld is good, easy to slag removal, resulting in less toxic gas.


Flux generally considered small viscosity, improved slag fluidity, so that the weld is good. High-viscosity flux generated weld no ripple, but the molding defects. When using special low-melting point solder, the larger the flux melting capacity, the greater the pressure on the surface of the molten pool, resulting in gas precipitation difficulties, the gas concentrated in the slag below the weld instability. In order to obtain a good weld, the thickness of the slag should be around the right side of the arc chamber. As the temperature changes, the viscosity should be moderate.