Evaluation of the quality of layers applied by LDT laser metal deposition
DOI:
https://doi.org/10.24136/atest.2018.140Keywords:
weld, welding quality, laser metal deposition, LDT technique, surface engineering, regeneration of partsAbstract
The article presents the results of a study of C45 carbon steel hardfacing using laser metal deposition with Stellit Co-21 powder. The microstructure of the cross-section of samples prepared with different scanning speed and the amount of used powder at constant laser power was observed. Analyzing the cross-sectional areas of the samples, it was found that, at specific production parameters, cracks occur in weld overlay, which should be associated with the amount of heat supplied and discharged, especially at the unheated basis.This may be confirmed by the presence of deposits of weakly branched dendrites in the microstructure, which should be related to the directional heat dissipation process and rapid directional crystallization. It is possible to regulate these phenomena by selecting appropriate processing parameters. The microstructure analysis of cross-sectional areas of samples after hardfacing using LDT technique indicates good metallurgical quality of the deposit with a small heat affected zone of about 660÷760?m. The microhardness measurements on the sample cross-sections indicated a wide micohardness distribution ranging from 510HV1 in the weld overlay, about 410HV1 in the heat affected zone, to 270HV1 in the C45 steel base.
Downloads
References
Burakowski T., Wierzchoń T., Inżynieria Powierzchni Metali, WNT, Warszawa 1995.
Herzog D., Seyda V., Wycisk E., Emmelmann C., Additive manufacturing of metals, „Acta Materialia” 2016, s. 371–392.
Kusiński J., Lasery i ich zastosowanie w inżynierii materiałowej, Akapit, Kraków 2000.
Mazurkiewicz A., Nędzi B., Analysis of selected properties of an article made from metal powder using laser additive manufacturing. Journal of Machine Construction and Maintenance. “Problemy Eksploatacji – Maintenance Problems” 2017, nr 2 (105), p.79-86.
Tatarczak J. i inni, Przegląd nowoczesnych technologii druku 3D obiektów metalowych, „Mechanik” 2017, nr 7, s. 612-614.
Durejko T., Łazińska M., Przetakiewicz W., Wytwarzanie materiałów na osnowie fazy Fe3Al techniką LENS, „Inżynieria Materiałowa” 2012, nr 5, s. 353-357.
Napadłek W., Chrzanowski W., Woźniak A., Przyrostowe technologie 3d w odbudowie kształtu zużytych eksploatacyjnie łopat turbin parowych, „Autobusy” 2017, nr 12, s. 1147-1152.
