Φ273mm Assel轧管机组生产薄壁无缝钢管的工艺开发

Development of Process of Rolling Light-wall Seamless Tube with Φ273 mm Assel Pipe Mill

Assel轧管机生产薄壁无缝钢管(径壁比≥25)时,存在着荒管头部易产生喇叭口,轧制过程中荒管甩动大,内表面易产生内螺纹缺陷等问题,严重制约着机组产能的释放。湖北新冶钢有限公司通过采用增设轧管机后台导卫装置及前台检测装置,改进轧管机辊型,优化轧制工艺参数等措施,大大减少了轧制过程中轧扭、卡钢事故的发生,轧制的薄壁无缝钢管内螺纹缺陷也明显减轻,壁厚精度达到±8%,成材率在90%以上。

In case of rolling light-wall seamless steel tubes with D/S ≥25 with the Assel mill, several problems are apt to be encountered with, including forming of bell-like end of the shell, strenuously swinging of the shell during rolling, and developing of defective inner surface spiral mark and so on, which greatly impede fully tapping of the operation line’ s production capacity. Accordingly, a series of technical modification actions are taken by Hubei Xinyegang Steel Co., Ltd., including adding a guiding device to the run-out table and relevant measuring units to the incoming section, improving the roll profile of the mill and optimizing the rolling process parameters, etc. As a result, failures as occurring in the rolling operation like material twisting or jamming are considerably reduced, and the severity of the said inner surface spiral mark is so lessened, while the tube wall thickness tolerance is tightened up to ±8%, and the mill yield increased to over 90%.