Requirements of standard
According to the requirements of TIS24-2548(2005) Thailand Industrial Standard for Steel Bar for Reinforced Concrete : Deformed bar in the topic number 1.2 specify that “Deformed bars shall be manufactured directly, by hot rolling, from billet-,bloom- or ingot-steel made by the open hearth, basic oxygen or electric arc furnace process.” This article will explain about the process of “electric arc furnace process”. This show in detail.
Electric Arc Furnace (EF)
The electric arc furnace process is popularly steel making process in America. Many manufacture use this process around 20% in 1975 and increase to 50% in 2000 because of this process consume the energy less than other process. The electric arc furnace process start with input the scraps into the furnace after that the electrode rod that applied the electric current are moved to close the scrap. The high voltage electrode pole and scraps are more than 500 volt and occur electric arc that increase the temperature of scraps more than 2000˚C . This temperature will change solid scraps to liquid metal. While scrap have been melted ,the arc process will reduced gradually and then oxygen have been filled into the liquid metal for oxidation reaction. After oxidation reaction the impurities in liquid metal will be oxide form and form to slag. In this method will remove contaminated alloy and purify liquid metal. After that the liquid metal will transfer next process for add alloy as standard’s requirement. All of this process are make batch to batch that not continuous production but the advantage of this process is better control the quality of each batch more than continuous process.