Super high power EAF for small size billet –refining ladle furnace—vacuum degasser—full horizontal round billet production process, there are 2 sets of 45 tons super high power electric furnaces, three sets of 45 tons ladle furnaces, one set of vacuum degasser, three sets of tow strands horizontal continuous casters. The in house developed horizontal continuous casting technology has reached the Chinese and international leading level . Bow type continuous casting process for large size billet production adopts the super high power EF—refining furnace—vavuum degasser—four strands bow type continuous casting process, there is one 90 tons super high power EF,one 100 tons ladle refining furnace, one 100tons vacuum degasser, one four strands bow type caster. Φ720 Mill is a large size seamless steel pipe production line newly built by Hengyang Steel, it is a key project of Hengyang steel, it is also a foundation stone for Hengyang Steel to realize the goal of 3 million annual production capability. The designed annual capacity is 150,000tons per year, size range is Φ273～720×8～120mm.φ89、φ219、φ340 hot rolling mills：φ89 mill was built in 1990s, it adopts tow roll cone type piercing—six stand semi floating mandrel MPM—24 stands stretch reducing process, main production facilities were imported from Germany.φ50 cold drawing line：it adopts peircer, pickling, high precision cold drawing machine, continuous annealing, high precision 17 roll straightener.