平板闸阀壳体预制孔缺陷破坏声发射检测

ACOUSTIC EMISSION DETECTION OF FLAT GATE VALVE SHELL PREFABRICATED HOLE DEFECT

对PFF52-70 MPa平板闸阀壳体预制孔缺陷,并进行破坏声发射检测。通过检测阀门壳体孔缺陷在压力载荷下扩展释放的声发射信号,达到对缺陷扩展特征参数的提取。在压力达到8.7 MPa时,阀门孔缺陷开始扩展,释放出明显的声发射信号。PFF 52-70 MPa平板闸阀壳体材料为40Cr Mo,在阀门壳体至端部,缺陷声发射信号幅度衰减<5d B。试验发现,声发射技术能对阀门壳体缺陷的动态扩展进行精确定位。

The PFF52- 70 MPa high pressure flat gate valve shell prefabricated hole defect was tested by the acoustic emission test( AET). AET technique could obtain the signal that the gate valve shell hole defect releases under ultimate pressure to extract the characteristic parameter of the defect spreading.When the pressure is up to 8. 7MPa,the hole defect begins to expand and release acoustic emission signal obviously. The shell material of PFF 52- 70 MPa gate valve is 40 CrM o. The attenuated amplitude of the signal is less than 5dB from the shell to the end. The test results showed that the AET could identify the dynamic expansion of the shell defect precisely.