There are several AAR and European standards available for axle testing of rail cars for both passenger and industrial purposes. Which one would govern your case would be determined by your local transportation authority and/or the owner of the rail cars.
I have also had contact with Lavender NDT in this regard, they provide an excellent level of consulting services for the rail industry.
An alternative would also be the BHP Rail Institute in Melbourne Australia.
David Hermanutz RTD Quality Services Pipeline Integrity North America
----------- Start Original Message ----------- : : Dear friends ! : I am looking for a NDT procedures at tubular axles : (railway underground systems).If somebody can help me, : please send me an answer as soon as possible. : Thank You ! ------------ End Original Message ------------