金属油气管道腐蚀的β射线检测方法

Metallic gas and oil pipeline corrosion detection method byβray detection

利用放射性物质衰变释放的粒子流在穿越不同厚度的屏蔽材料时,粒子输运过程和能量衰减程度不同的特性,提出通过检测管中β放射源产生的β粒子在管道外部形成的能量沉积,对架空金属油气管道的腐蚀状态进行在线无损检测的方法。分析了β粒子在穿越不同厚度的钢铁屏蔽材料后光子和电子流量与其能量分布的差异与特性,模拟试验β放射源投入管道后衰变产生的β粒子从内部穿透出不同腐蚀程度的金属管壁进入外部NaI粒子探测器的粒子输运结果,最后通过方差分析研究腐蚀厚度和面积对射线探测法的灵敏性影响。研究结果表明:射线探测法对腐蚀厚度的检测灵敏性强,该方法能够有效检测出厚度超过管道壁厚40%以上的腐蚀破损。

The particle transport process and the degree of energy attenuation are different when the particle flow released by the decay of the radioactive source crosses the shielding materials of different thickness.Making use of this feature,a method that measuresβparticle's energy deposition caused by internalβradioactive source at outer side of the pipeline was proposed to realize online nondestructive corrosion detection for aerial metallic oil and gas pipeline.The differences and characteristics of photon,electron flux and their energy distribution whenβparticles passed through steel shielding materials of different thickness were analyzed.Afterβradioactive source was devoted into the pipeline,the transport results ofβparticles generated by the decay which penetrate the metallic pipeline walls with normal and different corrosive degrees and eventually enter the NaI particle detectors were tested.Variance analysis was carried out to compare whether the thickness or area was more sensitive to this method.The results show that the ray detection method has strong sensitivity to the detection of corrosion thickness.This method can effectively detect corrosion damage with thickness exceeding 40%of the wall thickness of the pipeline.