The section size of casting bloom to roll 60 kg/m heavy rail of steel U75V (%: 0.71 ~ 0. 80C

0. 50 - 0. 80Si

0. 70 ~ L 05Mn

0.04 -0.12V

0. 23Cu) is 380 mm x280 mm and the section area of rolled piece out of second stand rougher mill is 18 015 mm

2

. A finite element model is established by rolling deformation test and microscopic observation and measure combining with technical parameters at production situs to study and analyze the effect of rolling deformation on depth of decarburized layer of heavy rail. It is obtained that as the bloom is rolled by primary stand mill and second stand rougher mill

decarburized layer of rail head decreases to 0. 53 mm from 1.2 mm

decarburized layer of rail waist decreases to 0. 54 mm from 1. 5 mm and decarburized layer of rail bottom decreases to 0. 83 mm from 1. 5 mm. The measured decarburized layer of finished rail head is 0.2 mm.