药芯焊丝钢拉拔断丝机理及控制  

Causes and countermeasures of drawing fracture for flux-cored welding wire steels

作　　者：邓小旋[1,2] 季晨曦[1,2] 肖茂元 罗磊 潘宏伟[1,2] 边吉明 王雷川 DENG Xiaoxuan JI Chenxi XIAO Maoyuan LUO Lei PAN Hongwei BIAN Jiming WANG Leichuan(Shougang Research Institute of Technology, Shougang Group, Beijing 100043, China Steelmaking Department,Shougang Jingtang United Iron ＆ Steel Co. ,Ltd., Tangshan 063200,China Beijing Key Laboratory of Green Recyclable Process for Iron ＆ Steel Production Technology, Beijing 100043, China)

机构地区：[1]首钢技术研究院,北京100043 [2]绿色可循环钢铁流程北京市重点实验室,北京100043 [3]首钢京唐钢铁联合有限责任公司炼钢部,河北唐山063200

出　　处：《炼钢》2017年第4期67-72,共6页Steelmaking

摘　　要：针对某钢厂铝镇静药芯焊丝钢拉拔频繁断丝问题,分析了断口形貌与成分,并结合生产工艺提出了断丝机理与控制措施。断口电镜分析发现:断口形貌发生扭曲分层,能谱分析表明导致分层的物质为保护渣。对比焊丝钢断丝炉次与正常炉次工艺参数发现断丝炉次液面波动小于±3 mm的比例为73%~87%,明显低于正常炉次。焊丝钢拉拔断丝机理为:由于吹氩量过大和水口结构不合理导致液面波动过大,引起结晶器保护渣卷入被凝固坯壳捕获,残留在铸坯并延续到冷轧卷。拉拔过程中钢材发生畸变分层,当拉拔力超过其能承受最大拉应力时发生断裂。从防止卷渣角度提出了控制连铸吹氩量、改变浸入式水口底部结构等措施,实施改进措施后拉拔断丝率从8.7%降至0.5%。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. 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 %.

关 键 词：药芯焊丝 断丝 卷渣 水口结构 

分 类 号：TF777.1[冶金工程—钢铁冶金]