thyssenkrupp Steel Europe AG (Dortmund, Germany):

G. Parma, Mag. Eng., Expert product development — Metallic coatings, e-mail: georg.parma@thyssenkrupp.com
T. Wuttke, Mag. Eng., Senior expert new coating technologies and pilot production

thyssenkrupp Steel Europe AG (Duisburg, Germany):
M. Norden, Dr. Eng., Team leader, Continuous galvanizing line No. 1

The results of the industrial trials utilizing the flameless burner technology in the DFF heating section prove that a homogeneous preoxidation of the strip can reproducibly be generated by a controlled variation of the λ-value. Furthermore the positive effects regarding the galvanizability of alloyed steel concepts applying the pre-oxidation technique have been confirmed. However, it should be noted that the outlined process window is only suitable for the given steel concept at the set process parameters, such as time, temperature, and dew-point for the pre-oxidation as well as for the reduction step. In terms of a deeper insight into the interaction between the oxidation and reduction conditions and for a fine-tuned process control the following aspects should be considered. Sectioning the pre-oxidation zone enables a variable control of the pre-oxidation temperature and time and as a result grants a customized operation for specific steel concepts. In addition to that the conception of an oxide sensor installed at the end of the pre-oxidation zone providing information on the generated oxide thicknesses would empower a precise process control.

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