Billet
What is a Billet?
Billet or sword: This type of billet is often used in Extrusion Industries and is manufactured on the basis of customer's request for alloys according to international standards, in dimensions of 125 and 150 mm, in different lengths.
Production Of Steel Billets
Steel Billets are intermediate rolling steel products that are manufactured in either Billet or Bloom form. The billet has a cross-sectional area of less than 230 cm and is circular or square with a width of less than 15 cm and is used for the production of rebar and wire. Bloom has a cross-sectional area greater than 230 cm and square in width over 15 cm and less than 30 cm and is used for Rail, Beam, Cans, Angles, Channel, T Bar and so on.
The technologies used in the production of steel products in the later stages of obtaining molten steel, such as casting and rolling, are almost identical. But to obtain molten or crude steel, various technologies can be used, such as the Blast - Furnace (BF), Electric Arc Furnace (EAF) and Induction Furnace (IMF). Although most crude steel production in the world is produced by the blast furnace method, for many reasons the use of induction furnaces, especially in Iran, is more justified.
Induction Furnace Production(IMF)
Induction furnaces are one of the most common furnaces for melting ferrous alloys. Induction furnaces operate based on magnetic field induction. The performance of it as follows : first by using the city's power supply and by the frequency converter, a relatively large current (more than 4 amps) is generated with a frequency of 300 to 10,000 Hz. Then This current is applied to the coil of the furnace, and by passing it generates a magnetic field of the same frequency in the middle of the coil. If Scrap or other metals placed in the middle of the coil, the magnetic field created induces eddy currents in these objects and these induction currents ,heat the object and move it to a melting point.
Generally, different parts of induction furnaces are:
- Crucible; containing stainless steel furnace, coil, fireproof wall, transformer core, yoke or platform (platform)
- Electrical installations : including Circuit Breaker, Disconnector, Transformers, Frequency converter, Capacitors, Cooler Switches, Suctions and Control Panels .
- Cooling Installations: Induction furnace electrical installations such as transformers, capacitors, high-pressure switches and control circuit boards can operate within a certain time frame and cause problems if they become warmer, so these faciliti
• Furnace Pit : Includes Furnace Pit Room, Foundation, Emergency Drain Pits, Electric, Hydraulic and Cooling Installations, and Control Circuit Boards, Water Circuit Control Panel and Hydraulic Control Panel.
• Ventilation Facilities : furnace dust and dust collector, especially in large Crucible furnaces, can also be considered important installations.
• Each of the above six sections has its own maintenance issues and plans, depending on the type of furnace (channel, crucible), pit capacity, furnace frequency (linear, medium, high), furnace cooling system, pit motion system and The type of refractory wall differs but there are many similarities in the principles.
• The operating frequency range of the furnace is from 1 Hz to 1 kHz or even greater.
The most important factors contributing to the high efficiency are: careful implementation of the furnace maintenance program, proper charging, proper operation, refractory wall condition.
Accurate execution of furnace maintenance program in induction furnaces depending on its type (channel, powered window), its capacity, frequency value, type of cooling system, pit motion system and refractory wall has its own maintenance program and It must be executed carefully.
The advantages of induction furnaces in comparison to other furnaces:
- Simple operating due to complete electronic control unit.
- Lack of pollution and oxidation due to lack of gas and oxidizing flame.
- Quick start and no need for preheating or melting.
- High speed of operation compared to other furnaces.
- High efficiency compared to fuel furnaces.
- Ability to control the temperature precisely.
- Scrap melting ability.
- Occupying less space than other furnaces.
- No impact on environmental pollution.