The Defects Of Double Metal Composite Pipe Researched By Micro Magnetic Detection Technology

Recently, the mechanical composite pipes are widely used with the characteristics of low prices, excellent mechanical properties and the stronger corrosion resistant ability.In the process of actual production, due to the composite tube manufacturing technology is difficult, in the tube body it always appears lamination defects and corrosion defects. And due to improper welding technology, in the pipe weld it appears welding defects, for example welding beading, lack of penetration, burn through,undercut, slag inclusion and so on. Therefore, in order to ensure the quality of the use of composite tubes, the mechanical composite pipes are tested in need before delivery.Due to nondestructive tests have their own limitations and the particularity of composite tube structure, the conventional methods make the pipeline detection rate and detection efficiency lower.It is proposed in this paper that the mechanical composite pipes are detected by micro- magnetic detection technique, ensure the security of the composite pipe using after the factory. Based on the principle of micro magnetic detection, combined with the characteristics of composite tube, using the micro magnetic detection system test the composite tube, which has lamination and corrosion defects produced by artificial prefabricated. Firstly, in order to achieve the demand of composite tube detection, it is studied and designed the micro magnetic detection system, including tooling parts,micro magnetic sensor, transmission, signal acquisition and data processing, and host computer. This system comes true automate the composite pipe efficient detection.Secondly, according to the characteristics of two kinds of defects,it is analysis and comparison that the defects of original curve shape changes in software. And it is also studied the relationship between the defects depth and the intensity of magnetic field changing. And then, for testing the corrosion and slag inclusion defects on the weld,the results show that the weld have a large effect on the detection performance, but the difference after amplifying and filtering, the micro-magnetic detection technology still has a good effect. Finally, based on the test results, it is using the C # programming language to compile the two-dimensional imaging of code. It makes the result more clear.This essay provides a new thinking and new method for testing the composite pipes, laying the foundation for the engineering application of composite pipes in the future.