气炉热处理钢丝在线磷化工艺研究

Online phosphating process research of steel wire heat treatment by gas furnace

利用气炉热处理酸洗磷化连续生产线对直径2.0～4.0 mm 72A钢丝进行热处理和表面处理,成品钢丝出现直径超差和表面质量较差等问题。SEM分析发现酸洗后钢丝出现"瘤包",影响磷化效果,其原因主要是热处理过程中,钢丝表面生成过多Fe2O3而影响酸洗效果。改变热处理和酸洗工艺参数,Dv值由60 mm.m/min改为55mm.m/min,线温由940℃改为930℃,盐酸质量浓度由120～150 g/L变为140～160 g/L,酸温由(50±5)℃变为(60±5)℃,热处理和表面处理效果明显改善,拉拔速度由200～300 m/min提高到400～500 m/min,每吨钢丝拉丝模耗由12只降到4只,成品钢丝表面质量较好。

Making use of the gas furnace heat treatment online pickling phosphating working line to heat treat and surface treat diameter 2.0 - 4.0 mm 72A steel wire, appears such problems as finished steel wire diameter out of tolerance and bad steel wire surface quality. It is found by SEM analysis that steel wire appears nodular package which influence phosphating effect, the cause is producing too much Fe2O3 on steel wire surface in the course of heat treatment, which influence pickling effect. By changing heat treatment and pickling process parameters, the heat treatment Dv value changed from 60 mm· m/min to 55mm·m/min, wire temperature ehanged from 940 ℃ to 930 ℃, hydrochloric acid mass concentration changed from 120 - 150 g/l. to 140 - 160 g/L, the acid temperature changed from （50 ± 5 ） % to （ 60 ±5 ） ℃, the heat treatment and surface treatment effect improved obviously, the wire drawing speed increased from 200 - 300 m/min to 400 - 500 m/min, wire drawing die consumption deereased from 12 pieces per ton to 4 pieces per ton steel wire, the surface quality of finished steel wire is better.