超声波检测试块真实缺陷的精度验证

目的 研究超声波检测试块中真实缺陷的形态、精度及其偏差产生原因，为进一步提高试块精度提供技术支持。方法 采用射线检测、超声检测及解剖测量方法，对自主研发的超声检测试块中植入的真实缺陷进行了检测，分析了缺陷的几何尺寸及位置坐标参数与设计值之间的偏差及其产生原因。结果 经表面打磨后，缺陷植入痕迹已完全消除，植入的裂纹形态自然，闭合度较好，且端点清晰，无二次扩展现象。经植入焊接后，缺陷载体与试件母体形成完全冶金结合，植入缺陷与自然缺陷在超声波检测信号上无区别，且在探头到缺陷之间的声束路径上，没有显示异常的反射界面或次生缺陷信号。由射线和超声检测可知，缺陷的几何尺寸及位置坐标的偏差为±2.2 mm。由解剖测量可知，平均偏差绝对值小于0.7 mm。结论 缺陷植入前设定的熔化余量与植入过程中焊接所产生的端部熔化量之间的差异造成了植入缺陷尺寸和位置与设计值之间的偏差。

Precision Validation of Real Flaws in Ultrasonic Testing Plates

The work aims to study the morphology, precision and deviation causes of the real flaws in ultrasonic testing plates, so as to provide technical support for further improving the precision of testing plates. The ultrasonic testing (UT), radiographic testing (RT) and anatomical measurement were employed to measure the implanted real flaws in self-developed ultrasonic testing plates, and the deviation between the geometric size and coordinate parameters of the flaws and the designed values as well as the causes were analyzed. The track of implanting flaws was grounded completely after surface polishing and the cracks were natural in morphology with good closure. The tips were distinguishable without secondary propagation phenomenon. After implantation welding, the flaw carrier and the specimen matrix formed a complete metallurgical bond. The implanted flaws and natural flaws had no difference in ultrasonic testing signal and there was no abnormal reflection interface or secondary flaw signal on the sound beam path from the probe to the flaw. According to the RT and UT results, the average tolerances of the flaw size and location coordinates were ±2.2 mm and their absolute values were all less than 0.7 mm by anatomical measurement. The slight deviations of the flaw size and location are mainly caused by the difference between the melting margin sets of the flaws before implantation and the melting amount of the flaw ends during implantation welding process.