... to fully adopt their corrosiveness;6. Control system is adopted rectifier unit DC bus power supply ... used full digital inverter speed control system of SIEMENS;7. Main control system: process control, speed control, ... line, stainless steel pickling line, 12 hi/ 6 hi reversing cold rolling mill, skin pass mill, tension leveling line, bright annealing line, electrolytic tinning line, galvanized line ...