水平连铸圆管坯超声检测信号识别方法研究

水平连铸圆管坯是一种多晶种各向民性的粗晶材料。当采用超声波对其进行质量检测时，必然会受到组织散射噪声的干扰而造成无法正确判断缺陷回波信号的困难。在分离频谱法的基础上，提出一种识别与判断缺陷回波信号的新方法－－瞬时频谱法。它以各时刻缺陷回波组成的分离信号序列的瞬时频带宽度为对象来研究识别缺陷回波信号的途径。实验结果表明，该方法不但可正确地识别缺陷回波信号，还可判断强烈的组织散射噪声中是否包含缺陷信号

RESEARCH ON IDENTIFICATION OF ULTRASONIC SIGNALS FOR HCC ROUND STEEL BILLET INSPECTION

The horizontally continuous cast (HCC) round steel is a kind of multi gcrystal, elastic anisotropic and coarse grained material. When ultrasound is used to inspect its quality, it is difficult to distinguish the defect echo correctly because of the influence of the structure scattered noise. In this paper, a new technique for the identification and judgement of the defect echo signals, Instantaneous Spectrum Analysis technique, has been developed based on Split Spectrum technique, which recognizes the defect echo signals by taking into account the instantaneous bandwidth of the sequence composed of split signals produced by the defect echoes at every instant Experimental results show that this new technique can not only identify the defect echoes correctly, but can also judge if there is any defect signals mixed with strong structural noise and point out the position.