Study On Weak-magnetic Testing Technology For Pipeline Corrosion Defects With Cladding Layer

The energy make full of use is becoming highly attention with our country vigorously promote the strategy of conservation and environmental protection energy.Therefore,the pipeline with cladding layer structure was adopted in many industrial fields.It can prevent the loss of heat energy,improve the conversion parameters of medium,and also reduce the risk of corrosion caused by rain and other harmful media,and raise the life of pipeline operation.However,the pipeline corrosion is inevitable as the growth of the pipeline operation years,which will bring the major security risks to pipeline operation.So the corrosion under insulation urgently need a testing technology for nondestructive testing,ruled out the major security incidents.Theory analysis and experimental research on weak-magnetic nondestructive testing about ferromagnetic pipeline corrosion with an aluminum cladding layer have been done in this paper.First of all,the contrast testing experiment of ferromagnetic pipeline itself and with cladding layer was carried out,and the testing feasibility of pipeline corrosion defects with cladding layer structure based on weak-magnetic nondestructive testing was discussed.The testing capability of corrosion defects was compared by change the probe arrangement position for obtain the best testing way.Then the experiment have been done through change thickness of the insulation layer,and analyzed the effect on weak-magnetic signal,the testing reliability which weak-magnetic nondestructive testing technology on pipeline corrosion defects with cladding layer was proved when insulation layer under certain thickness.Combining with the characteristics of weak-magnetic testing signal,the way of data processing was studied on this kind of pipe,the extraction and determine technology of defect have been done by using the probability method and the wavelet analysis method,both of the advantages and disadvantages was analyzed,and the characteristics of weak-magnetic testing signal on artificial flat board was studied for quantitative study of defects.Finally,the ferromagnetic pipeline corrosion defects with cladding layer testing software platform system was written by using C# language based on the study content of this article and the 2-d imaging analysis of discrete data,it has realized the data collection、analysis,defect extraction、quantitative and 2-d imaging functions.The software platform system was used in industrial environment practice,andachieved good detection results on the scene.The application reliability of weak-magnetic nondestructive testing technology on pipeline corrosion defects with cladding layer was further validated.It was established a good foundation for the subsequently weak-magnetic nondestructive testing technology research.