Surface welding is welding process for surface improvement, usually used to improve corrosion resistance or surface hardness. For this diploma thesis, seven steels with different chromium contents were single-bead manually arc welded onto the 20 mm thick construction steel with coated electrode. All welds were welded with same welding parameters. The samples were analyzed with EDX line scan analysis on the scanning electron microscope. On each sample there were made five different line scan analyses in different positions. By means of line analysis we tried to find out usability of EDX line scan analysis for determination of admix rate of base material in single-bead weld from chemical composition of base and filler materials. Calculated admix rates, determined by chemical composition measured with EDX line scan analysis were compared with admix rate determined by geometric method and method calculated witch chemical composition measured with EDX area scan analysis. Results indicated that EDX line scan analysis is accurate enough for calculation of admix rate and are comparable to the other two methods. It was also found out, that admix rate calculation from chemical composition is only valid if both single-bead weld and filler metal compositions were measured with same scanning electron microscope. In addition, the partially mixed zone was investigated in different positions in single-pass weld. Results showed that partially mixed zone is the widest on the middle of the weld and the narrowest on the edges of the weld.
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