Spiral submerged arc welding pipe production molding

　　Spiral submerged arc welded pipe production, forming and welding is carried out simultaneously, so the stability of the welding quality is good or bad and forming inseparable. Molding seam ebbed and flowed, "pout", the tight loose outside the tight loose inside, pitch shifting of local wrong side, squeeze the thick side plates, missing the cut, wave, burrs and bevel irregular porosity, lead to adverse and weld undercut, burn down, pores, slag and other defects forming. Therefore, we found it necessary to promptly adjust molding instability.

　　The flux of foreign influence and control weld shape spiral submerged arc welded pipe weld quality and chemical composition of the flux, viscosity, bulk density, particle size and stack height and other factors are closely related.

　　Chemical composition and viscosity of the flux component has a great influence on the weld. Although various manufacturers solder flux are in line with GB / T 5293-1999 standards, but because of its formula, its metallurgical properties and process performance are not the same. When choosing, we can observe, test, analyze and compare, select the best person. The choice of flux should ensure that you have good metallurgical and technological properties, stable arc slag has a suitable melting point, viscosity and surface tension, and the weld is good, easy slag removal and produce fewer toxic gases.

　　Flux is generally believed that small viscosity, improving the fluidity of the slag to make a good weld. High viscosity flux resulting weld no ripple, but molding defects. When using a particularly low melting point solder, flux melting capacity of more weld pool surface pressure, causing the gas precipitated difficulties, the gas concentrated in the slag below, so that weld is not stable. In order to obtain a good weld, slag thickness around the arc chamber to the right, with the temperature changes the viscosity should be moderate.