Rapid Non-destructive Examination Device And Experimental Study Of Signal Processing For Rof Bottom Plate

Rotary Annealing Furnace is used for high temperature anneal of Oriented Siliconsteel.ROF bottom plate is one of the main consumable parts for the ROF. It bears theheat treatment work pieces (Oriented Silicon Strip) in the process of high temperatureanneal. The service life of bottom plate of annealing furnace is connected with thecircular stress. By means of finite element method，the values of temperature anddistribution of heating stress are given in the paper. In the process of high temperatureanneal, the biggest heating stress is produced in the fringe, which dues to theasymmetry temperature of the bottom plate.Draught stress is the ultimate cause of thecrack. In the process of cooling, the fringe of the bottom plate bears the draught stress,at the same time the limit of intensity is lower under the effect of hightemperature.The bottom plate crack easily.ROF bottom plate need to be test by Ultrasonic Nondestructive Testing beforeworking. ROF bottom plate was a large area material of disc-shaped,two meters indiameter. It was complex operating,low detecting efficient,great laborintensity.Missed and error detection were common occurred.So based on Immersion testing or direct contact method,an auxiliary device wasdesigned to help scanning ROF bottom plate.The probe was driven by the auxiliarydevice in different radius could achieve scanning all area rapidly,moving flaw detectorand probe simultaneously was no longer need. Fluid couplant was automaticallyimposed when pushing forward the device.So this non-destructive examine methodcould achieve high efficient,low labor strength,less missed and error detection.ROF bottom plate is made of coarse grain steel.The ultrasonic echo signals arepolluted and submersed,so the Split Spectrum Processing(SSP) method areresearched.This method has superiorities in extract the faint flaw wave.The SSP iscomposed of two stages as spectrum and signal recovering.The minimizationalgorithm and polarity thresholding algorithm are most commonly used.But they aresensitive to the parameters of the filter bank,the effect is not very good.So,consecutivepolarity coincidence algorithms is proposed.This method is more effective than theother two common signal recovering method by theoretical and methodologicalresearch.