全浮芯棒二辊孔型中轧管金属变形行为研究

Research on the Deformation Behavior of Metal During Tube Rolling Using 2-high Pass with Mandrel Mill

为分析连轧荒管管壁收缩的原因,借助有限元模拟软件MSC.Super Form,对宝钢Φ140 mm全浮芯棒连轧管机组Φ119 mm主孔型系钢管的单机架轧制过程进行数值模拟仿真,研究轧制过程中不同工艺参数对金属变形行为的影响,分析产生壁厚收缩缺陷的倾向性。结果表明:孔型顶部的壁厚压下量一定时,孔型开口处壁厚随空减坯径壁比的增大由"增壁"变为"减壁",并且存在一临界径壁比;径壁比一定时,孔型开口处壁厚变化随压下量的增大由"增壁"变为"减壁",并存在临界压下量;径壁比、压下量均一定时,单机架轧制高钢级时孔型开口处壁厚值相对较大。

In order to analyze the reason of steel tubes wall-thickness shrinkage produced by continuous rolling mill, the single pass rolling process of Φ119 mm main pass system of Φ140 mm mandrel mill in Baosteel was simulated with the aid of the FE software MSC.Super Form. The influence of process parameters on the deformation behavior of tubes was investigated, and the occurrence of the tendency of wall-thickness shrinkage defects as well. Results show that： with the reduction of wall-thickness unchanged, the wall thickness at the roll gap changes from＂wall increase＂to＂wall decrease＂as the D/S ratio of the reduced hollow shell increases, and there is a critical D/S ratio; with the D/S ratio fixed, the wall thickness at the roll gap changes from＂wall increase＂to＂wall decrease＂as the reduction of wall thickness at the groove bottom increases, and there is also a critical reduction value; when both the D/S ratio and the reduction of the tube wall are kept the same, the wallthickness value at the roll gap is relatively larger as rolling with single pass for hi-grade steel.