爆炸复合板压力容器径向裂纹的无损检测及其安全性分析

Non-destructive testing and safety analysis of explosive radial crack of composite plate pressure vessel

通过直探头、斜探头、TOFD (超声波衍射时差法)等方法,对S31603/Q345R复合板压力容器的径向裂纹进行无损检测以比较其缺陷检出能力;通过扫描电镜观察其微观结构,分析其失效机理;最后,通过数值计算分析其安全性能.结果表明,直探头检测时回波面较小易导致漏检,TOFD检测时不锈钢粗晶粒产生的回波易掩盖径向裂纹产生的回波从而导致漏检,而斜探头因检测回波面大,检测效果优于直探头和TOFD,建议采用斜探头检测以确保径向裂纹的检出;通过扫描电镜发现爆炸复合板结合界面呈明显的正弦波状且存在元素相互扩散现象;且结合界面处存在的裂纹、空洞等缺陷使其强度降低;最后,通过数值计算分析发现该类裂纹的存在使得复合板压力容器存在较大的安全隐患.

In this paper,the radial crack of S31603/Q345R composite plate pressure vessel was tested by means of ultrasonic straight probe detection,ultrasonic oblique probe detection and TOFD detection(ultrasonic diffraction time difference method)and the defect detection ability was compared.Then,the electron microscopy was used to analyze its failure mechanism.Finally,the safety performance of a pressure vessel with radial crack was analyzed by finite element analysis.The results show that the radial crack was easy to be ignored due to the fact that the ultrasonic plane of ultrasonic straight probe detection was narrow,as TOFD produced a return to the coarse grain of the stainless steel to cover the echo generated when detecting the radial crack.Ultrasonic oblique probe detection was better than direct probe detection and TOFD detection,because the ultrasonic plane was wide.It is recommended to use the ultrasonic oblique probe detection to ensure the safety detection of the radial cracked composite plate pressure vessel.The results of scanning electron microscopy show an explosive composite plate with a clear surface of the sine wave surface and the combination of elements at the surface will be the phenomenon of mutual proliferation.The microscopic defects such as cracks voids and voids in the joint surface can reduce the strength of the bonding surface.Finally,the existence of such cracks put the composite plate pressure vessel at a large security risk by the finite element analysis of radial cracked composite plate pressure vessel.