轧辊在线消磁装置的设计和实现

Design and realization for roll online degaussing device

在轧钢厂轧辊裂纹和损伤的涡流检测中,需要对轧辊进行消磁处理。本装置基于消磁的基本原理,利用高磁导率的半圆环形铁氧体作为铁芯,采用四管推挽式驱动电路,由脉冲信号进行控制,在消磁线圈上通过幅度不变、方向交替变化的脉冲电流,从而在铁氧体的两个端面附近产生交变的消磁磁场。根据轧辊材料的频率响应特性和轧辊的转速等参数,通过计算和实验确定消磁频率和消磁功率,并利用单片机实现消磁过程中数据传输功能,通过计算机对消磁过程进行监控,实现生产过程中频率连续可调、实时显示。本仪器设定消磁频率在200～800Hz之间,消磁探头和轧辊表面之间保持1mm左右距离,消磁后,能将工件剩磁减小至小于0.1mT。实际应用表明,所设计的消磁装置具有较好的使用效果。

Degaussing＇in rolling mill is important for eddy current testing for crack and damage of roll. Based on the basic principles of degaussing, the device using the semi-circular ring of high permeability ferrite as the core, is controlled by pulse signal from four push-pull driver circuit which alternating pulsed current in the coil to generate the alternating degaussing magnetic field. The calculation and experiment is based on the roll material frequency-response characteristics and the roll speed and other parameters to determine the demagnetization frequency and degaussing power, and we use microcontroller to achieve the degaussing process data and transfer it to computer to adjust frequencies in the production process and carried out to monitor. The degaussing frequency of the instrument is set between 200-800 Hz, and the distance between the degaussing probe and the roll surface is about lmm, and the remanenee of the work-piece is less than 0.1 mT after degaussing. Practical application shows that the degaussing device has good effect.