Rapidly solidified nonequilibrium microstructure and phase transformation of laser-synthesized iron-based alloy coating

Authors
Citation
Xl. Wu, Rapidly solidified nonequilibrium microstructure and phase transformation of laser-synthesized iron-based alloy coating, SURF COAT, 115(2-3), 1999, pp. 153-162
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
SURFACE & COATINGS TECHNOLOGY
ISSN journal
0257-8972 → ACNP
Volume
115
Issue
2-3
Year of publication
1999
Pages
153 - 162
Database
ISI
SICI code
0257-8972(19990718)115:2-3<153:RSNMAP>2.0.ZU;2-L
Abstract
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. (C) 1999 Elsevier Science S.A. All rights reserved.