Asahi Industries Realizes High Quality and Low Cost Rebar by Low Temperature Extraction

Japanese major concrete reinforcing steel bar and structural steel maker, Asahi Industries will lower billet extracting temperature to 950 Celsius degrees in April 2011 in order to improve product quality and to reduce productive cost. The firm introduced 2 rolling machines for low-temperature extraction at Saitama plant in Saitama Prefecture, Japan in mid 2010. These machines are now under test operation and quality verification. The extracting temperature was downed to around 1,000 degrees from previous 1,100-1,150 degrees.

Higher mechanical properties of rebar contribute to less consumption of manganese and silicon. The firm has used manganese at about 700 kilogram per charge and silicon at about 100 kg per charge so far. The usage volume is expected to decrease by 50 kg for manganese and by 5 kg for silicon. As for structural steels, the firm becomes to increase utilization of low grade ferrous scrap without quality down by lowering surface reduction rate.

Asahi Industries has already succeeded in surface quality improvement for steel products. Especially for 19/22 millimeters diameter rebars, for which high rolling speed is required, low-temperature billet extraction contributes to less scale generation. Moreover, low-temperature finishing roll realizes straightness of the procducts.

Asahi Industries has implemented capital expenditure of total 20-30 billion yen for late 5 years, including construction of a new heating furnace, capacity up of rolling mill motors and conversion of DC controlling facilities into AC. The firm almost completed 5-year capex plan by introduction of new 2 rolling machines. The firm now operates total 20 rolling machines.