Abstract: At panzhihua Iron and Steel Company,hydrogen content in molten heavy rail steel is rather low during smelting in the oxygen top-blown converter,and sloightly increases in tapping and pouring.Average H content varies from 2.0(dry season)to 2.4 ppm(rainy season)at smelt- ing end;2.8 ppm in ladle;and 2.1 ppm(dry season)to 2.3 ppm(rainy season)in mould, which is on a level with RH vacuum circle.The low hydrogen content in molten steel,which is due to both the very dry climate in Panzhiihua region and the LD smelting process,is the main reason why there is little flake in the heavy rail produced by Panzhihua Iron and Steel Com- pany.

Key words: smelting, rail steel, hydrogen, LD process, flake