1119 レールの転がり損傷に関する研究  [in Japanese] Study on contact rolling fatigue of rails  [in Japanese]

As far as the surface defects on the rail head, there are two kinds of defects called on "head check" and "dark spots" (shelling defects) in the Shinkansen's rail. In addition "White Phase" exists in the surface layer of rail head. The contents discussed in this paper are Contact Rolling Fatigue of Rails in the high-speed rail tracks. The authors have focused on "White Phase". It is clear that the initiation of "contact rolling defects" relates to Hertzian stress, Lubrication, tangential force etc. The main results obtained in the present study are as follows : (1) The occurrence of White Phase is attributed to alternate between water lubrication condition and dry condition. (2) The tangential force affect cracks initiation and propagation materially. (3) White Phase occurs in the origination of shelling early.