Cold expansion of new fishbolt holes in austenitic manganese steel rails for MTRC, Hong Kong (RR-STR-94-082)

Austenitic manganese steels (AMS) differ fundamentally from conventional BS11 grade steels. In the "as received" condition the material is relatively soft; however, if the surface layers are subject to abrasion the surface rapidly work hardens (from approx. 220BHN to 500BHN) whilst the underlying material remains comparatively unchanged. AMS therefore has...