The rapidly solidified microstructural and compositional features, the prec
ipitation and transformation of carbides during tempering, and the impact w
ear resistance of an iron-based alloy coating prepared by laser cladding ar
e investigated. The clad coating alloy, a powder mixture of Fe, Cr, W, Ni,
and C with a weight ratio of 10:5:1.1.1, is processed using a continuous wa
ve CO, laser. Microstructural studies demonstrate that the coating possesse
s the hypoeutectic microstructure comprising the primary dendritic gamma-au
stenite and interdendritic eutectic consisting of gamma-austenite and M7C3
carbides. gamma-Austenite is a non-equilibrium phase with an extended solid
solution of alloying elements. During high temperature tempering at 963 K
for 1 h, the precipitation of M23C6, MC and M2C carbides in austenite and i
n situ carbide transformation of M7C3 to M23C6 and M7C3 to M6C respectively
are observed. In addition, the microstructure of the laser-clad coating re
veals an evident secondary hardening and a superior impact wear resistance.
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