Evolution of microstructure in laser clad Fe–Cr–Mn–C alloy

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 in the weight ratio 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 an ultrafine microstructure in the clad alloy layer. 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 transformation or retained austenite phase.

MST/356