厚壁奥氏体不锈钢对接接头的相控阵超声检测

Phased array ultrasonic testing of thick-walled austenitic stainless steel butt joint

奥氏体不锈钢对接接头凝固时未发生相变,室温下以铸态柱状奥氏体晶粒存在,晶粒粗大,超声波散射严重,衰减大;柱状晶粒具有各向异性,超声波在其中传播时声束被扭曲,定位误差较大。使用相控阵超声检测技术,采用双晶面阵探头和单晶线阵探头对奥氏体不锈钢对接接头试块进行检测,并结合CIVA仿真结果,证明相控阵超声技术能够实现对奥氏体不锈钢焊缝的检测。

Austenite stainless steel butt joint shall not undergo phase transformation during solidification.At room temperature,as cast columnar austenite grains exist with coarse grains,which shall result in serious ultrasonic scattering and large attenuation.Columnar grains are anisotropic,and the sound beam shall be distorted when ultrasonic wave propagates in it,resulting in large positioning error.The phased array ultrasonic testing technology is used to detect the austenitic stainless steel butt joint test block by using the dual crystal plane array probe and the single crystal linear array probe.Combined with the CIVA simulation results,it is proved that the phased array ultrasonic testing can realize the detection of austenitic stainless steel weld.