Product
Kariya Plant Products

Stainless steel is a type of steel made from iron that contains at least 11% chromium.
It has excellent corrosion resistance, design characteristics, high-temperature strength, low-temperature toughness,
non-magnetism, resistance to hydrogen gas embrittlement, and other properties,
and is used in a wide range of fields including construction, civil engineering, water treatment, and energy.
In addition, stainless steel is easily recycled, making it an environmentally friendly recyclable resource.

Stainless Steel

Where can you find stainless steel ?

  • Corrosion resistance Vertical greening cylinders at Aichi International Convention & Exhibition CenterPhoto courtesy of SS. Inc. Vertical greening cylinders
    at Aichi International Convention & Exhibition Center
  • Design characteristicsInterior stairs in Aichi Steel Administration BuildingInterior stairs in Aichi Steel Administration Building
  • High-temperature strengthTunnel fire extinguisher mounting fittings on the Shuto Expressway Shinjuku RouteTunnel fire extinguisher mounting fittings
    on the Shuto Expressway Shinjuku Route
  • Low ductility in low temperatures Internal deck and stairs inside LNG tankPhoto courtesy of Toho Gas Co., Ltd. Internal deck and stairs inside LNG tank
  • Non-magneticOverall frame of the Kyushu University Research Institute of Superconductor Science and SystemsOverall frame
    of the Kyushu University Research Institute
    of Superconductor Science and Systems
  • Resistance to hydrogen embrittlementReceptacle on the MIRAI fuel cell vehicleReceptacle on the MIRAI fuel cell vehicle

Main Points of the Stainless Steel Business

Aichi Steel Holds Top Share in Japanese Production of
Stainless Steel Shapes and Flat Steel
Since 1958, when we started producing Japan’s first hot-rolled stainless angle bar at the Kariya Plant, where we were founded, we have provided the market with over 4,000 products of different shapes, dimensions, and steel types.
Aichi Steel’s share of domestic production of flat and shaped stainless steel products exceeds 70%.
  • Aichi Steel Holds Top Share in Japanese Production of Stainless Steel Shapes and Flat Steel
Enhanced Stainless Steel
Building Structure Engineering Functions
Aichi Steel established stainless steel structural engineering functions in 1996 and is involved in all process from design cooperation with general contractors and others to plant production of materials and components and onsite installation and civil engineering work.
In 2019, Aiko Corporation, a subsidiary, constructed the Kinuura No. 2 Plant, expanding plant manufacturing capabilities.
  • Examples of productionExamples of production
  • Examples of productionExamples of production
Diverse Technical Capabilities Support the
Stainless Steel Product Portfolio
We use simulation technologies that employ rolling FEM analysis to develop practical machines for an extensive range of steel shapes based on high-precision and optimized investigations of designs.
In conjunction with the spread of hydrogen energy, we are developing material evaluation and testing equipment that can operate under high-pressure hydrogen environments, accelerating the development of stainless steels for high-pressure hydrogen, and we are working to enhance their reliability.
  • Results of a rolling FEM analytics simulationResults of a rolling FEM analytics simulation
  • Rotating bending fatigue test apparatus corresponding to high-pressure hydrogen environment (World’s First)Rotating bending fatigue test apparatus
    corresponding to high-pressure
    hydrogen environment (World’s First)

Flow
Production Flow

  1. 1. Raw Materials
    The main raw materials used in stainless steel are nickel and chromium imported from various other countries and stainless steel scrap, which is 100% recycled in Japan.
    The specified amounts are blended according to the composition of the products and fed into an electric furnace.
    Key point
    • There are more than 30 different types of stainless steel scrap, a main ingredient used in making stainless steel, and the different types are used according to the product composition standards.

  2. 2. Steel Making
    After the main raw materials are melted in an electric furnace using the arc heat from electrical sparks generated by graphite electrodes, ferroalloys are added to create the desired composition while impurities are removed.
    Once the composition is adjusted, the molten stainless steel is continuously poured into molds and uniformly cooled to form solidified stainless steel nuggets known as billets.
    Key point
    • The arc heat generated by the graphite electrodes in an electric furnace is said to be hotter than 5,000°C, heating the molten stainless steel to more than 1,600°C.

  3. 3. Rolling
    Steel that has been formed into shapes that are easy to use as industrial material is called steel material. Our stainless steel material is manufactured using a hot rolling process. The billets made in the manufactured process are re-heated, and the product shapes are formed by repeatedly placing the material into the gap between a pair of rotating rollers and extruding it.
    Key point
    • The rolling line at the Kariya Plant is a multi-rolling line that can produce about 650 different types of steel material.

  4. 4. Heat Treatment
    The rolled stainless steel material is heated to about 1100°C in a heat treatment furnace and then quickly cooled to adjust the internal structure of the material.
    The surface of the steel material that has been heat treated is covered by oxidized scale and is black.
    Key point
    • The heat treatment furnace at the Kariya Plant uses carbon-neutral city gas.
      We are looking into use carbon-free fuel to achieve carbon neutrality in the future.

  5. 5. Pickling
    To provide the steel material with excellent corrosion resistance, the surface is washed with acid to form a very thin and fine oxidation film (a passive film).
    During the pickling treatment, the steel material is dipped in an acid shower. The surface of the steel material exposed to acid in this way turns the silvery-white color for which stainless steel is known.
    Key point
    • We use an environmentally-friendly nitrogen-free acid solution.

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