Microstructure evolution of Fe-based nanostructured bainite coating by laser cladding

被引：38

作者：

Guo, Yanbing ^{[1
]}

Li, Zhuguo ^{[1
]}

Yao, Chengwu ^{[1
]}

Zhang, Ke ^{[1
]}

Lu, Fenggui ^{[1
]}

Feng, Kai ^{[1
]}

Huang, Jian ^{[1
]}

Wang, Min ^{[1
,2
]}

Wu, Yixiong ^{[1
,2
]}

机构：

[1] Shanghai Jiao Tong Univ, Sch Mat Sci & Engn, Shanghai Key Lab Mat Laser Proc & Modificat, Shanghai 200240, Peoples R China

[2] Shanghai Jiao Tong Univ, Sch Mat Sci & Engn, State Key Lab Met Matrix Composite, Shanghai 200240, Peoples R China

来源：

MATERIALS & DESIGN | 2014年 / 63卷

基金：

中国国家自然科学基金;

关键词：

Laser cladding; Nanostructured bainite coating; Microstructure; Carbon content; Hardness; HIGH-SILICON; HIGH-CARBON; TRANSFORMATION; FERRITE;

D O I：

10.1016/j.matdes.2014.05.041

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

A Fe-based coating with nano-scale bainitic microstructure was fabricated using laser cladding and subsequent isothermal heat treatment. The microstructure of the coating was observed and analyzed using optical microscope (OM), field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The results showed that nanostructured bainitic ferrite and carbon-enriched retained austenite distributed uniformly in the coating. Blocky retained austenite was confined to the prior austenite grain boundaries resulting from the elements segregation. The bainitic microstructure obtained at 250 degrees C had a finer scale compared with that obtained at 300 degrees C. The volume fraction of austenite increased with increasing transformation temperature for the fully transformed bainitic coating. The bainitic transformation was accelerated as a result of the fine prior austenite generated during the laser cladding. The evolution of the carbon contents in bainitic ferrite and retained austenite revealed the diffusionless mechanism of the bainitic transformation. (C) 2014 Elsevier Ltd. All rights reserved.

引用

页码：100 / 108

页数：9

共 23 条

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