Chita Plant Products

Specialty steel is iron to which special metals (ferroalloys) have been added.
Depending on the ferroalloys that are added,
we can create specialty steels with various properties such as being harder, tougher, more heat resistant, or more machinable than general steel.
Aichi Steel makes use of this characteristic to develop specialty steels optimized according to customer wishes.

Specialty steel is used in automobile components that are crucial for safety and must operate under demanding environments
such as the engine and suspension, taking advantage of its strength.

Specialty SteelSpecialty Steel

Where can you find specialty steel ?

  • AutomobilesAutomobiles
  • Machine tools and construction equipmentMachine tools and construction equipment

Main Points of the Specialty Steel Business

Resource Recycling Business
Uses Steel Scrap as a Raw Material
In our manufacturing business, we use steel scrap generated during automobile body processing and from end-of-life vehicles as a raw material.
As a recycling-oriented company, we are contributing to the preservation of the global environment through our business by recycling steel resources.
  • ScrapyardScrapyard
  • Electric furnaceElectric furnace
First Use in Japan of Waste Heat
from an Electric Furnace to Convert Steam Energy
We introduced a mechanism that passes waste heat from electric furnaces through a boiler to recover the heat in the form of steam energy and effectively uses that energy in vacuum degassing equipment and other steel manufacturing equipment.
This is the first case of such use of waste heat in the Japanese electric furnace industry. This system enables us to cut CO₂ emissions by the equivalent of approximately 4,200 tons annually.
This innovative system is contributing to carbon neutrality.
to Achieve
  • Exhaust heat recoveryExhaust heat recovery
  • Vacuum degassing unitVacuum degassing unit
Composite Steel Making Process
Used to Achieve Number One Production
on Single Bar Rolling Line in Japan
and Top Domestic Share for Hot-Rolled Steel Bars
(Low-Alloyed Steels for Machine Structural Use)
Aichi Steel began operation of the world’s first composite steel making process, which links multiple steel making devices in a series, in 1982.
To raise high competitiveness in the areas of quality, price, and delivery time, we have continuously developed facilities since then.
The steel blooms manufactured using this process pass through rolling and inspection processes and are supplied to customers in the form of high-quality specialty steel bars.
  • Diagram of the composite steel making processDiagram of the composite steel making process
  • Cooling bed of the rolling plantCooling bed of the rolling plant

Production Flow

  1. 1. Raw Materials
    The main raw material for our steel production is steel scrap. There are various types of steel scrap such as the scrap generated from automobile body processing and iron from end-of-life vehicles.
    By combining multiple types of scrap according to the type of steel to be produced, we can optimize quality and cost.
    Scrap is fed into an electric furnace in a timely manner from indoor and outdoor yards.
    Key point
    • 20,000 tons of scrap (about one week’s worth) is stored in the outdoor scrapyard at all times.

  2. 2. Steel Making
    Steel scrap is fed into a 150-ton electric furnace, and three graphite electrodes are inserted into the furnace. Ultra-high voltage electricity is passed through the electrodes to generate arcs like lightning. The heat from the arcs melts the steel scrap.
    The melted steel is transported to a ladle furnace and vacuum degassing unit where the composition is adjusted, and then large pieces known as blooms that weight 5 tons and are 3.5 m long are made by a continuous casting machine.
    Key point
    • The melted steel is heated to a temperature of 1,600 degrees, which is hotter than magma. Heat resistant bricks are attached to the inside of the electric furnace and the ladle to prevent them from melting.
    • The iron recycling rate is as high as 95%, with electric furnace manufacturers making major contributions.

  3. 3. Rolling
    During the rolling process, the cast blooms produced during the steel making process are rolled in a rolling mill to a particular thickness and length according to the customer’s specifications. By passing the billets through 27 rolling mills, the bars are gradually changed into round bars with the dimensions requested by the customer.
    Key point
    • The smallest bar products have a diameter of 17 mm, while the largest have a diameter of 100 mm.
    • The total length of the rolling plant building exceeds 400 m.

  4. 4. Conditioning and Inspection
    Various devices for detecting flaws are used to perform rigorous inspections, enabling us to supply specialty steel products that customers can use safely and with confidence.
    Three-quarters of products are shipped as-is, while the remaining quarter are transported to our in-house forging process for use as raw material for forging.
    Key point
    • Ultrasonic flaw detectors, magnetic flaw detectors, and other devices are used to perform inspections, and inspections are conducted according to the precision requested by the customer.

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