The continuous cooling transformation ( CCT) curves of U75V steel (/% ； 0. 75C

0. 63Si

0. 95Mn

0. 025P

0. 004S

0. 26Cr

0. 05V) are measured by a Gleeble-3500 thermal simulation testing machine

and the calculated model for temperature field and structure transformation of 60AT rail during air-cooling process after rolling is established by using DEFORM-3D finite element software to study and analyze the effect of temperature and structure on bending deformation of 60AT rail during 150 ~700 s air-cooling process after rolling. Results show that the effect of great volume to surface- area ratio of rail waist of 60 AT rail on distribution of temperature at whole rail section is larger

with rail air-cooling for 150 s

there is no phase transformation at section of 60AT rail and the structure is all austenite

with temperature dropping i. e. air cooling for 650 s

the 97. 2 % austenite at rail section transfers to pearlite

besides the effect of structure transformation on bending deformation of rail is larger

at end air-cooling the bending deflection of rail in K-direction (lateral bending) is -0. 07 mm

i. e. the bending is toward rail bottom short edge

and the bending deflection of rail in Z-direction (positive bending) is 0. 228 mm

i. e. the bending is toward rail head. The calculation results are available for reference of pre-bending in rail straightening process.