65钢丝拉拔断裂分析与盘条生产工艺改进

从盘条生产方面分析65钢丝拉拔断裂的原因:盘条存在表面脱碳、裂纹、中心缩孔等缺陷,钢中非金属夹杂物级别较高,盘条金相组织控制不好,存在不利于拉拔的网状铁素体。提出防止拉拔断裂的盘条生产工艺措施:优化精炼造渣工艺,电磁搅拌电流300～400A,频率4Hz,二冷配水比水量1.7L/kg,保持连铸过程拉速在1.8～2.4m/min,全程保护浇铸,开轧温度1000～1050℃,吐丝温度840～870℃,优化控冷工艺等。措施实施后盘条金相组织中未发现网状铁素体,索氏体化比例提高,盘条表面未发现脱碳、裂纹,拉拔断丝明显减少,65钢盘条实物质量稳定提高。

Drawing fracture analysis of 65 steel wire and wire rod production process improvement

The cause of 65 steel wire drawing fracture is analyzed from wire rod production, that is ： decarbonization and crackle appears on the wire rod surface, shrinkage void in the center; non-metallic inclusions grade of steel is higher; microstructure control of wire rod is not good, which exists net ferrite that is unfavorable to wire drawing. The production process measures to prevent from drawing fracture are put forth： to optimize refining slagging; electromagnetism stirring electricity is from 300 A to 400 A, frequency is 4 Hz ; special water flowrate of secondary cooling is 1.7 L/kg ; to keep with- drawal speed at 1.8 - 2.4 m/min in the course of continuous casting, and protection casting in whole course; rolling start- ing temperature is at 1 000 ~ 1 050℃, wire rod laying temperature is at 840 - 870 ℃, and to optimize cooling control temperature. After practising these measures, net ferrite microstructure is not found in wire rod, sorbitizing rate increases, decarbonization crackle is not found on wire rod surface, wire drawing fracture phenomenon is decreased obviously, the practical quality of 65 steel wire rod is heightened stably.