Decarburizing and coating lines
for silicon steels

A decarburizing and coating line (DCL) reduces the carbon content of the steel by heating the strip up to the decarburizing temperature, and then applies onto its surface a water based magnesia slurry thanks to a coating machine. 

The main goal of this line is to deliver a product that can be used in the high temperature annealing made by batch annealing (HTA).

Drever International furnaces allow to heat the strip in a controlled atmosphere to keep a clean surface suitable before the coating process with magnesia. They have also a perfect control of the heating and of the cooling rate requested to perform the heat treatment of the most advanced steel grades.

    DCL for silicon steels

    After cold rolling, the strip is delivered to the decarburizing and coating line. To remove the carbon contained in the steel, it must be reheated to a temperature in the range of 840°C – 860°C. This temperature is held for a long time in a wet HNx atmosphere: this is the decarburizing. A nitriding section can follow this decarburizing section. The strip is cooled down afterwards, first slowly then at higher rate to a temperature low enough so that it can be coated with a magnesia slurry.

    Our mathematical model as well as our dedicated control system drive the temperature of the different zones of the furnace to reach the requested microstructure and properties at the end of the line.


    The usual configuration for the decarburizing and coating lines is horizontal.


    Drever International supplies a combination of three technologies to reach the desired decarburizing temperature:


    Drever International relies on electrical heating or gas-fired radiant tubes to hold the temperature during the decarburizing.


    After the decarburizing, the strip must be cooled down before the magnesia coating. A slow cooling is followed by a quicker cooling provided by HNx jets.

    • Cooling tube section that can be equipped with electrical heating.
    • Slow cooling with plenums blowing hot HNx. This section can also be equipped with electrical heating.
    • Fast cooling with plenums blowing cold HNx

    Drever International delivers

    • The annealing furnace and the cooling section 
    • The control system and a mathematical model of the furnace 

    Our parent company, SMS group and its affiliates deliver all the other equipment of the line.
    More information on SMS group offer