提高精密合金中厚板超声波探伤灵敏度的探索  

Investigation on the Increase of Sensitivity with Ultrasonic Testing for Medium Plates of Precission Alloys

作　　者：韩锋[1] 张晓义[1] 王颖[1] 

机构地区：[1]北京北冶功能材料有限公司,北京100192

出　　处：《金属材料研究》2016年第1期37-42,共6页Research on Metallic Materials

摘　　要：超声波探伤是无损检测技术中的一种，广泛应用于金属材料领域的生产检验。一个良好的超声波探伤系统的探测深度可达lO000mm，但由于系统中的声压空间分布特性导致在实施探伤时，被探测工件表面存在着菲涅尔区（近场区），在此区域内，声压起伏剧烈，无法对小于探头面积的缺陷波进行识别，故又称该区域为“盲区”。菲涅尔区的存在对小规格工件的超声波探伤检测造成了很大影响，甚至无法实施探伤。因此，文章对减少、消除该区域的尺寸进行了探索性实验。通过实验，发现对系统中的换能器（探头）进行调整组合后，可以有效地大幅减少近场区的距离，从而达到对10～20mm厚的板材实施小缺陷的检出。在检出Φ4mm、Φ2mm当量缺陷的时候，系统灵敏度余量分别达到54dB和46dB。Ultrasonic inspection is one kind of nondestructive testing which is wildly used in metal material＇s examination. The detect depth could be 1 000 mm for a good ultrasonic detection. The distribution character of sound pressure could lead to Fresnel zone appeared in the surface of the work piece. In the Fresnel zone, the flaw could not be detected because the sound pressure fluctuates violently. The Fresnel zone affects the result of detection seriously, especially for the small work pieces. In this paper, tests were done to decrease the Fresnel zone. It was found that the optimized the combination of the probes could effetely decrease Fresnel zone, for example, for the Φ4 mm or Φ2 mm flaw in the 10-20 mm thick plate, the sensitivity margin of the system could be 54 dB and 46 dB.

关 键 词：菲涅尔区 双晶探头 试块 平底孔 灵敏度余量 

分 类 号：TG132.22[一般工业技术—材料科学与工程]