A study on Metallurgical quality of first heat U71Mn and U75V heavy rail steel produced by 100 t LD-LF- VD-280 mm x 380 mm casting bloom flow sheet has been carried out. Statistic results show that although the overheating extent (21 ~38℃) of first heat liquid is higher

the max hydrogen content

oxygen content in end-half heat of first heat decrease respectively by 0. 2 x 10

-6

and 5 x 10

-6

as compared that in beginning-half heat and the max rating of inclusions also decrease by 0. 5. The metallurgical quality of end-half heat meets the requirements of heavy rail steel

therefore it is available that the end-half heat of first heat liquid can be cast for heavy rail instead of crane rail. As the process is put into practice

the amount of heavy rail steel shall increase more than 60 000 t per year.