无缝钢管三辊轧制荒管壁厚偏心分析

Analysis on wall thickness eccentricity of three-roll rolled hollows of seamless steel tube

三辊轧制荒管壁厚偏心控制是无缝钢管壁厚精度控制的重要环节。基于生产试验分析了荒管壁厚偏心的特征,运用解析方法建立了三辊轧制荒管壁厚偏心的理论计算模型,针对实际生产条件进行了预报计算与比较,分析了三辊轧管工艺因素对荒管壁厚偏心的影响特点,并进一步讨论了改善荒管壁厚偏心的方法。研究结果表明,荒管壁厚偏心的基本特征表现为"偏心螺旋型",在荒管壁厚不均中的占比达80%以上;毛管壁厚偏心和温度偏心是影响三辊轧制荒管壁厚偏心的最重要因素;增大三辊轧制减壁量、降低毛管温度、提高轧辊台肩高度、增大轧辊转速有利于减小荒管壁厚偏心。

The wall thickness eccentricity control of hollows rolled by a three-roll tube mill is an important part of the wall thickness precision control of seamless steel tubes.Based on production trials,this paper analyzes the characteristics of the wall thickness eccentricity of hollows,establishes the theoretical calculation model of the wall thickness eccentricity of three-roll rolled hollows using analytical methods,carries out the prediction calculation and comparison according to the actual production conditions,analyzes the influence characteristics of the three-roll rolling process factors on the wall thickness eccentricity of hollows,and further discusses the methods to improve the wall thickness eccentricity of hollows.The results show that the basic characteristics of the wall thickness eccentricity of hollows are"eccentric screw type",accounting for more than 80%of the uneven wall thickness of hollows.The eccentricity of the wall thickness and temperature in shells are the most important factors affecting the wall thickness eccentricity of the three-roll rolled hollows.Increasing the reduction of the three-roll rolling,reducing the temperature of shells,increasing the height of the roll shoulder,and increasing the rotation speed of the rolls are conducive to reduce the wall thickness eccentricity of hollows.