本文对超声波探伤判定 缺陷的当量尺寸进行了理论分析,并联系新制轮箍中内部缺陷的规律,提出轮箍内部缺陷大小的判断仅仅通过标准试块进行比较衰减值是有误差的,必须先用探头在标准试块上作出不同深度的2平底孔AVG曲线图,然后用实测dB值比较才正确判断出缺陷的当量大小。 In this paper, the theoretical analysis of the equivalent size of defects in ultrasonic flaw detection and the relationship between the internal defects in the newly made wheel hub and the judgment of the size of the internal defects in the wheel hub are made only by comparison with the standard test block. The attenuation value must be used first Probes in the standard test block made at different depths of 2 AVG flat bottom hole curve, and then compared with the measured dB value correctly determine the equivalent size of the defect.