提高衍射时差法超声检测近表面缺陷的能力

Improvement of the detect ability of TOFD detect devices for the near-surface defects

为了提高衍射时差法超声检测(TOFD)近表面缺陷的能力,用理论计算和实测方法确定了TOFD检验技术的盲区。通过选用不同频率的探头组,降低探头间距(PCS)及采用双面扫查方式减小盲区的大小,可以对近表面盲区的检测质量进行有效的控制。

In order to imporove the detect ability of TOFD detect devices for the near - surface defects, the blind spot of TOFD inspection technology was determined by theoretical calculations and experimental method. Detect quality in blind spots near the surface can be effective controled by selection of groups using different probe frequencies, reduction the probe spacing （PCS） as well as use of double -sided scanning mode to reduce the size of blind spot.