【摘要】 从厚壁压力容器近表面缺陷的检出率和缺陷尺寸定位定量的精准性角度出发,开展205 mm厚壁试块超声波衍射时差法(TOFD)上分区检测实验,结合上分区的整体成像结果,验证理论计算得出的通过改变探头间距和入射角来减小上表面盲区的方法是否可靠。实验结果表明,TOFD具有很强的独立发现上表面盲区内缺陷的能力,但无法获得缺陷自身深度和高度的精确定量,结合相控阵技术则可以有效提高近表面检测效果。更多还原

【Abstract】 From perspective of thick-walled pressure vessel near-surface defect detection rate and accuracy of defect size positioning and quantifying,upper tier detection experiment on 205 mm thick-walled test block was carried out by using time of flight diffraction(TOFD) technology. The reliability of methods of changing probe centre separation and angle of incidence to decrease the dead zone in the upper surface was verified combined with whole-body imaging result of the upper tier. The experimental result shows that TOFD has strong ability to independently detect the defect in the upper surface dead zone, but it can not accurately determine flaw depth and height. However combined with the phased array technique, its near-surface detection effect can be effectively improved.更多还原