初轧机主传动系统的扭振是造成部件破坏的主要原因.本文指出初轧机的扭振实质上可分为冲击扭振和自激扭振两大类.分析产生各种不同扭振的原因,提出了各种扭振时TAF值的计算方法,并对TAF值可能达到的水平做出预测.指出危险情况和预防原则. Torsional vibration of the main drive system of the initial rolling mill is the main reason for the damage of the components.This paper points out that the torsional vibration of the initial rolling mill can be divided into two major categories: impact torsional vibration and self-excited torsional vibration.This paper analyzes the causes of various torsional vibrations, Various calculation methods of TAF value in torsional vibration are put forward, and the possible level of TAF value is predicted, and the dangerous situation and precautionary principle are pointed out.