INVESTIGATIONS INTO QUALITY ASSURANCE OF PLASMA-WELDING CORROSION-PROTECTIVE CLADDINGS USING ONLINE ELEMENT-SPECTROMETRY

Cladding of high-grade corrosion resistent protective layers by means of plasma-welded claddings is applied with great success if the the ge ometry and size of the workpiece restricts the application of other co ating-techniques. Especially if Ni-alloys which are sensitive to dilut ion are to be used the corrosion resistance is however reduced by chan ges of the chemical composition. By means of process optimization and a continuous control an evenly distributed and minimized dilution can be achieved. With a direct measuring of the element concentration in the weld pool of the plasma welding process it is attempted to improve process-control and quality assurance. The pursued aims in this respe ct are an increase of the performance of an on-line element spectral a nalysis of the plasma are and their employment in the field of welding engineering. This contribution gives an overview of the conditions fo r an effective analysis method, requirements for the measuring set-up and the actual process as well as analytical approaches.