Experimental study on magnetic flaw detection of micro-defects in ERW tubes

Abstract

Abstract Chassis lightweight is one of the implementation of vehicle lightweight, the use of Electric Resistance Welding(ERW)welded pipe by bending and internal high pressure molding from the parts are an important part of the chassis components. Due to the limitation of welded pipe size, thin wall, high temperature and continuous production, the conventional nondestructive testing method is difficult to meet the continuous dynamic testing requirements of ERW welded pipe. In view of the small defect of ERW welded pipe, a method for detection of welded pipe defects based on the principle of electromagnetic induction is presented. Firstly, the fuzzy evaluation model of weld quality was established based on the fuzzy mathematics principle. Secondly, the welding mechanism of ERW was analyzed, and the microstructure of the weld was observed by metallographic microscope, and the microstructure of the weld was obtained. Finally, eddy current method, the low-frequency electromagnetic scanning method and magnetic induction method were used to detect ERW welded pipes. The data analysis shows that the magnetic induction method can realize dynamic detection and accurate localization of welded pipe defects, and the comprehensive detection effect is the best.