Microstructure and Wear Properties of Laser Clad Fe-Cr-Mn-C Alloys
by
Jogender Singh
J. Mazumder
Department of Mechanical and Industrial Engineering
Abstract
The laser surface cladding technique was used to form in situ Fe-Cr-Mn-C alloys on AISI 1016 steel substrate. In this process mixed powders containing Cr, Mn, and C with a ratio of 10:1:1 were delivered using a screw feed, gravity flow carrier gas aided system into the melt pool generated by a 10 kW CO2 laser. This technique produced ultrafine microstructure in the clad alloy. The microstructure of the laser surface clad region was investigated by optical, scanning and transmission electron microscopy and x-ray microanalysis techniques. Microstructural study showed a high degree of grain refinement and an increase in solid solubility of alloying elements which, in turn, produced a fine distribution of complex types of carbide precipitates in the ferrite matrix because of the high cooling rate. An alloy of this composition does not show any martensitic or retained austenite phase.
In the preliminary wear studies the laser clad Fe-Cr-Mn-C alloys exhibited far superior wear properties compared to stellite-6 during block-on-cylinder tests. The improved wear resistance is attributed to the fine distribution of metastable M6C carbides.
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