皮尔格冷轧无缝钢管成形过程组织演变过程研究

皮尔格冷轧技术作为冷轧无缝金属管材最主要的技术手段，具有材料利用率高、截面累积变形量大及加工精度高等特点，以LG-60皮尔格冷轧管机轧制304不锈钢为研究对象建立数值仿真模型，分析不同轧制工艺参数对皮尔格冷轧成形的影响规律。结合轧制实验，截取管材不同的变形段利用金相显微镜、扫描电镜以及X射线衍射仪分析研究了皮尔格冷轧过程中钢管组织演变规律，结果表明：本文所使用工艺参数条件均可以满足管材的塑性变形要求，但在轧制过程中极有可能形成裂纹或其他缺陷。因此通过对皮尔格冷轧仿真过程中轧制力、管材等效应力、残余应力以及外径回弹量等关键参数分析，获得基于送进量、回转角和Q值最优工艺参数，同时，发现轧制过程中随着变形量的增大，试样内部产生了大量位错，晶粒发生了碎化，晶粒尺寸减小，轧制过程中有奥氏体γ相转变为α''-马氏体相。

Study on Microstructure Evolution of Pilger Cold Rolled Seamless Steel Tube

Pilger cold rolling technology,as the most important technical means of cold-rolled seamless metal tube,has the characteristics of high material utilization,large cross sectional deformation and high machining accuracy 304 stainless steel rolled by LG-60 pilger mill was taken as the object of study and a numerical simulation model was established.With metallographic microscope,scanning electron microscope and X ray diffractometer,the evolution of the organization in the process of cold rolling steel was analyzed from the different deformation segments of the pipe.The results showed that the technological parameters can meet the requirements of plastic deformation of the tube.But in the rolling process,it is likely to form cracks or other defects during rolling.Therefore,key parameters such as rolling force,tube equivalent stress and residual stress during cold rolling simulation of pilger were analyzed and obtained.The optimal process parameters based on feed volume,back angle and Q value were obtained.It was also found that a large amount of dislocations were produced in the sample during the rolling process.The grain was broken and the size decreased.In the process of rolling,there was the transformation of austenite phase to alpha-martensite phase.