Abstract:
Longitudinal hot tearing, popularly called as end cracking, frequently takes place in the end portions of large steel panels’ butt joints, using one-sided, submerged-arc welding with flux copper backing welding process (FCB welding). The study was to look for the possibility to improve and/or prevent the end cracking issue during FCB welding, center blind-hole drilling technique was used to measure the welding residual stress for five different cases, considering hot tearing mechanism, its influence factors and the relevant reported prevention measures. Unpredictable result was observed subsequently that transverse compressive stress is found on the shallow surface of weld seams, which could give supplementary information to the common assumption for conventional low heat input welding method that cracks initiation is caused by tensile stresses across the welded joints. The study concluded that FCB welding end cracking issue is caused by the comprehensive function of different stresses, and also properly use tack welding practice, suitable elastic run-off plate and relatively low heat input energy which will reduce the end cracking susceptibility for the tested materials.
PRODUCTS This machine uses cymbiform submerged arc welding. The workpiece is fixed when welding, but the gantry moves. The gantry movement adopts the frequency control; The beam is equipped with 2 groups of guide column, each having a set of welding head. Sep 20, 2019 Submerged Arc Welding (SAW)—SAW process differs from most arc welding processes for, in the case of SAW, the electrical arc is submerged under a layer of flux. The flux covers the welding from atmospheric contaminants and prevents spatter or sparks from flying. Longitudinally Submerged Arc Welded Steel pipes. LSAW (Longitudinal double submerge arc welding) carbon steel pipe is a type of SAW pipe made of steel plates that were hot.
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