Study on Fast Inspection Method for Car Body of Railway Vehicle Welded by Laser Overlapped Thin Steel Plates with Lamb Wave

Abstract

A nondestructive testing method which can be used for finding lack of fusion defects in laser overlap welds every one of which joints two thin stainless steel plates is proposed based on reflection of ultrasonic Lamb wave. A B-scan testing system which implements the method is developed. Experimental testing on laser overlap welds of samples using the developed B-scan system is conducted. The results of experimental B-scan testing are compared with those of ultrasonic C-scan testing on the welds and observations on fracture surfaces of the welds. The agreements between the results of B-scan inspections and those of the other two kinds of inspections are satisfying. It is concluded that the developed B-scan technique is useable for inspections on laser overlap welds of rail vehicle bodies both in manufacture and periodical maintenance process.