关键词: 药芯焊丝 , 断丝, 卷渣, 水口结构

Abstract: To solve frequent broken for flux-cored wire during the drawing process in a steel company,the morphology and chemistry of the fracture was analyzed.And the broken mechanism and its countermeasures was put forward based on the production process.The distortion and lamination were detected with SEM for fracture analysis.The energy dispersive spectrometry show the mold powder account for that lamination.A comparison between the defective heats and normal heats show that the percentage of level fluctuation smaller than 3 mm of fractureinduced heats was smaller than the normal ones.Thus the mechanism of the broken wire can be summarized as follows:mold powder entrapments due to large level fluctuation occurs and it may be captured by the solidifying shell,persist in the slabs until to the cold rolled sheets.[JP2]The lamination occur because of the ductility difference between inclusions and matrix.The wire break when the pulling stress exceed the affordable stress of this defective wire.Several countermeasures were proposed to prevent the mold power entrapments,including controlling the argon gas flow rates changing the SEN bottom shapes,and so on.After applying these countermeasures,the wire fracture ratio decreased from 8.7 % to 0.5 %.

Key words: flux-cored wire, fracture, mold powder entrapment, submerged entry nozzle