| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 773668 | Engineering Failure Analysis | 2016 | 9 Pages |
•Defects in SAW-deposited chromium carbide overlay (CCO) are observed and characterized.•The main phases of CCO are identified by EBSD as primary Cr7C3, secondary Cr7C3 and Cr23C6 and austenite matrix by EBSD.•Un-dissolved Cr7C3 particles with porosities seem to provide the preferential nucleation sites for the initial micro-cracks.
Owing to their enhanced wear resistance, chromium carbide overlay (CCO) plates deposited by submerged arc welding (SAW) process have been widely used in various branches of the mining industry. Defects in the deposited CCO directly determine the wear performance of this material. Several characterization techniques, including optical microscope (OM), optical emission spectroscopy (OES), and field emission scanning electron microscope (FESEM) equipped with an energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD), have been used to identify the most common defects and phase distribution in the SAW-deposited CCO. The main phases are consist of primary carbide, secondary Cr7C3 and Cr23C6 carbides, austenite, and a small amount of ferrite. Defects in CCO, such as cracks, porosity, and clusters of particles known in the industry as “rice crispies” are observed near the top surface of the CCO. The undissolved Cr7C3 particles with surrounding porosity seem to have provided the preferential nucleation sites for the initial micro-cracks. These initial cracks are observed to propagate along the interface between the austenite and Cr7C3 carbides.
