• Annealing

    Annealing is a process in which cold rolled structures are converted to a recrystallized structure through heat treatment. For grain-oriented electrical steel, two different annealing methods are available: decarbonization annealing and high temperature annealing. Decarbonization annealing removes excess carbon from the steel and apply an MgO coating. High temperature annealing produces secondary recrystallized structures having superior magnetic properties.

  • Insulation Coating

    In this process, insulation coating is applied by a continuous coater roll in order to minimize eddy current losses, which are proportional to the sheet thickness. Grain-oriented electrical steel has two layers of coating, a base coating of dark brown Forsterite as the main ingredient and a transparent insulating coating containing phosphates. For non-oriented electrical steel, various coating methods with various thicknesses and ingredients are used depending on end usage and specific user’s requirements.

  • Preliminary Annealing

    During the preliminary annealing process, scale which may have formed on the hot rolled steel is removed as delayed passing through scale breaker and a hydrochloric acid bath. This initial heat treatment process improves cold rolling properties of steel as well as it’s magnetic properties.

  • Cold Rolling

    In order to obtain specific thickness and material properties, reduction ratio of 40~90% is applied normally. Rolling and edge trimming machines are automatically controlled to obtain uniform thickness and width.