Research On New Welding Materials In FCB Technology

Flux copper backing is one of one-side submerged arc welds, the backing flux is uniformly distributed on copper plate, then pressed on the plate by air pipe in order to get shapely back of weld. During the welding the flux and wires used in SAW are the chief consuming materials. To one's well-known, the flux which is rich in manganese and silicon matched low even no manganese wires is not only too much cost, but also makes a great deal pollution to the environment. Hence, it has better academic and applied value for the research, concerning the flux which is poor in manganese and silicon matched high manganese.The three-wire automatic SAW is chosen in experiment. The base metal is over 60mm's plate, butted joint. The A steel is welded, used new welding material. The processing parameters of the materials were assessed by the adjustment of welding current and velocity. The E steel is done in the same welding situation, used two different welding materials. Then the weld ability is compared.The results of mechanical test indicate, all samples meet the manufacturing requirement. Thereinto, the tensile strength of sample is lower and impact toughness is worst because of high energy input, the tensile strength of sample is higher than sample, but impact toughness is on the contrast.From the analysis of the microstructure, we have known that, the structure of welded seam is composed of proeutectiod ferrite, acerose ferrite, wildmanstaten structure, perlite and so on. Since the energy input is excessive, the grain of sample had severely coarsened. Sample hadn't formed homogenous and dense microstructure, which is similar with samples, for the lower element transfer.From the results of XRF and XRD we can see, the mainly component of new flux is SiO2-MgO-CaO-CaF2,the proportion of the previous three substances is over 60%. It belongs to CaO- SiO2 flux and its basicity is 1.72.The chemical constitution has told us that, the content of sulfur and phosphorus in welded seam of sample is higher than samples, meanwhile its rate of manganese to silicon is lower, the reason is that the efficiency of element transfer of sample is lower. Compared to the oxygen content of sample, it's higher inversely.