In Japan, rail bonds used for electrical connection between rails are joined to rails by the flame brazing method to use a tin-zinc brazing filler metal, which sometimes fall off from the brazed part to cause trouble for train operation. To prevent this problem, we discussed the application of ultrasonic inspection to the brazed parts. As a result, we have found that the rail bonds joined under improper brazing condition can be detected by the pulsereflection type ultrasonic inspection. This paper introduces the ultrasonic inspection and other joining technology in recent years.

Copyright (c) 2005 Railway Technical Research Institute