2250 mm热连轧产线轧辊利用率的提升实践

Practice of Improving the Utilization Rate of Rolls on the 2 250 mm Hot Continuous RollingProduction Line

热轧轧辊处于高温、高负荷和骤冷骤热的复杂环境下工作,如果轧辊冷却不足、带钢表面氧化铁皮较厚以及局部破碎,均会造成轧辊氧化膜异常剥落,从而加剧磨损,缩短轧辊使用周期,不利于生产效率提升。针对此现状,通过优化加热工艺,将低碳钢的出炉温度控制在1 210℃以下,高强钢的出炉温度控制在1 230℃以下,在炉时间控制在200 min以内,产生的氧化铁皮能被除鳞机清除干净;增加油膜润滑量及轧辊冷却水量、封堵边部喷嘴,可提高轧辊润滑和冷却效果,减少轧辊氧化膜剥落,提高辊面质量;投用机架间冷却水,将开度控制在80%以下,控制三次氧化铁皮厚度,并避免氧化铁皮破碎,同时提高轧制速度、缩短纯轧时间。实践表明:通过以上工艺改进,生产高表面等级品种时的轧辊有效公里数增加25%,轧辊利用率得到显著提高。

The hot rolling roller works in a complex environment of high temperature,high load,and sudden cooling and heating.If the roller is not cooled sufficiently,the iron oxide scale on the surface of the strip steel is thick or partially broken,it can cause abnormal peeling of the oxide film on the roller,which can exacerbate wear,shorten the service cycle of the roller,and is not conducive to improving production efficiency.By optimizing the heating process,low carbon steel is controlled below 1210℃,high strength steel is controlled below 1230℃,and the heating time is controlled within 200 minutes.The generated iron oxide scale can be cleaned by the descaling machine.Increase the amount of oil film lubrication,cooling water for the working roller,and plug the edge nozzles to improve the lubrication and cooling effect of the roller,reduce the peeling of the oxide film on the roller,and improve the quality of the roller surface.Put the cooling water between stands into use,with the opening controlled below 80%,control the thickness of tertiary iron oxide scale,and avoid iron oxide scale breakage.At the same time,improve the rolling speed and shorten the pure rolling time.Through the above process improvements,the effective kilometers of rollers increased by 25%when producing high surface grade varieties,and the utilization rate of rollers was significantly improved.