Comparative Study on Processing Property Between CWW CO₂ Gas Shielded Welding and SAW

Abstract

Cable welding wire (CWW) CO₂ gas shielded welding is an innovative process arc welding with high efficiency, high quality and low consumption, in which cable wire is used as consumable electrode. CWW CO₂ gas shielded welding and submerged arc welding (SAW) are used for contrast studies on processing property of high strength steel A36 used in ship structure. The results show that the shapes of weld seam, using CWW CO₂ gas shielded welding and SAW, are good and no weld defect such as air hole, flaw, slag inclusion, incomplete fusion, lack of penetration and so on are found in the weld seam. Because the rotating of arc during CWW CO₂ gas shielded welding process has a strong stirring effect on molten pool, the grain in the heat affected zone (HAZ) of the joints, using CWW CO₂ gas shielded welding, is small. Tensile failure positions of joints by CWW CO₂ gas shielded welding and SAW are all in the base metal, but tensile strength of CWW CO₂ gas shielded welding joint is higher than that of SAW joint by an average of 2. 3%. The average impact energy of HAZ, using CWW CO₂ gas shielded welding and SAW, is almost equal, but the average impact energy of the weld seam using CWW CO₂ gas shielded welding is increased by 6%, and the average impact energy of the fusion line is increased by 7%. The 180° bending tests for the joints of CWW CO₂ gas shielded welding and SAW are all qualified, and the joints hardness is all less than HV 355, but hardness of CWW CO₂ gas shielded welding wire welding joint near the fusion line is obviously lower. It can be concluded that the properties of CWW CO₂ gas shielded welding are better than those of the SAW joint, and CWW CO₂ gas shielded welding is suitable for welding high strength steel A36 used in ship structure.