基于超声相控阵的20钢内部缺陷检测精度研究

Research on Test Precision of 20 Steel Interior Flaw Based Ultrasonic Phased Array

采用超声相控阵对20钢试样横通孔缺陷深度进行了无损检测试验,分别研究了探头激发晶片数为4、8、16三种情况下,声束聚焦深度为6.35 mm、12.70 mm、19.05 mm、25.40 mm、31.75 mm、38.10 mm的缺陷深度检测精度。结果表明:近表面孔1、2受超声检测盲区的影响,检测精度低;孔1、2在激发晶片数为16时受近场区内声压波动的影响检测精度波动大,近场区外聚焦深度与缺陷深度相近时检测精度高;超声检测盲区和近场区外,检测精度随探头激发晶片数的增加而提高。通过对缺陷深度检测精度的比较,分析了检测精度的影响因素,为超声相控阵缺陷检测方法的选择和检测精度的提高提供了依据。

Non -destructive test experiments for 20# steel with SDH （side -drilled hole） flaw are carried out using ultrasonic phased array technology, to study test precision of flaw depth under three active element quantities（4,8,16） with six focusing distance （6.35,12.70,19.05,25.40、31.75、38.10mm）. Results show that ultrasonic blind distance has significant effect on test precision of near-surface flaw numbered 1 and 2, which is low. Flaw 1 and 2 test precision fluctuated largely with 16 elements, which are affected by near-field of the sound pressure fluctuations, but it is higher than others when focusing distance similar to flaw depth in the outside of near-field region. Without blind distance and near-field region affected on test precision, it becomes higher with the increase of element quantity. Affecting factors of test precision are analyzed by contrasting before and after test precision in this case, it proves evidence for choosing test method and increasing test precision.