Abstract
	Knowledge of the alloying elements distribution throughout the cross section of one layer, two layers and three layers welded-on pieces and also the evidence on the silicon alloying in welded-on pieces from the flux are presented in the paper. The presence of silicon in the welded-on piece evidently reduces the thickness of ? phase and ? phase layers during the nitriding process. It was proved that stiring of liquid basic material with additional alloyings only first welded-on piece layer had expressive amount of Mo and Cr. In the second and third welded-on piece layers the influence of basic material on alloying is slight only. Experimental results showed that the alloying elements distribution throughout the cross section of one layer, two layers and three layers welded-on pieces is uniformed. The alloying transition toward the basic material is realized in interlayer of 0.2 to 0.5 mm of thickness over the basic material. The Mo content in range of 0.5-1.7 %, when other alloying elements were kept constant, did not influence the traced properties of nitrided layer. In the thickness of the e-phase and a-phase layers and in microhardness /HV0,05/ along cross section of the nitrided layers no substantial differences were found. Only first weld-on piece  layer was significantly alloyed by mixture of basic material with additional material. The content of alloying elements in the second and third welded-on layers is same as in the used additional materials.