EAF: High Quality Steel-Making Process
Reinforced concrete structure requires quality steel that matches with the concrete in order to strengthen the structure according to construction design, its purpose, as well as to be safe. Controlling all of these aspects must cover from upstream process, that is the material especially structural material, design, construction process, up to submitting for occupancy permit and building management.
EAF: High Quality Steel Production
The process of making quality steel has at least two integral factors. First, raw material must be well selected. In the case of using steel scrap, it must be sorted according to its quality from the point of origin. Second factor is the production process or the melting process. The process with highest quality at present is the Electric Arc Furnace (EAF) process. The EAF process was widely used in the U.S.A. in 1975 AD. It was used to produce 20% of steel that same year and increased to 50% in 2000 AD. The growth is because this process uses less power comparing to other process where the quality is still at the required level.
The EAF process starts with putting steel scrap into the furnace, then electrode graphite rods with high current of more than 500V move towards the scrap resulting in induction at more than 2000 degrees Celsius that melted the scrap into liquid steel.
When all scrap is turned into liquid steel, oxygen is added to the mixture, which results in oxidation, forming slag so that impurities are taken out. This process purifies the liquid steel before adjusting the composition. These combinations of procedures are done in batches so that the quality of each batch can be controlled to the required standards.
Supports High-Grade Steel Production
Steel that are mostly used in Thailand are in SD40 grade, followed by SD50. In the meantime, steel manufacturers, government sectors, and related organizations have been working together to set a new industrial standard for SD60 rebar. The EAF process supports the production of SD60 as well as other specifications especially super ductile rebars for seismic-resistant structures.
The Electric Arc Furnace is the basis of TIS steel production and is an essential foundation in the development of higher quality steel.