Metallographic diagram of 35CrMo overlay welding WC alloy

, 描述35CrMo堆焊WC合金金相图

The field-emission scanning electron microscope (FESEM) was used to study the microstructures of 35CrMo welded tungsten carbide (WC) alloys. The composition of the investigated alloy was W-13.5 (mass%). The FESEM micrographs of WC alloys contain faceted W grains and a small amount of CrMo and a large amount of WC particles embedded in a matrix of Fe and Cr.

The fracture surface of the sample was observed and the trigonal-shaped particles were clearly visible. The presence of the trigonal-shaped particles indicates the solid-state reaction and diffusion between the WC particles and the matrix of Fe and Cr present in the alloy. This phenomenon was more apparent in the regions close to the interface between the two materials and is insufficient to strength the bond between the WC particles and the matrix of Fe and Cr.

TEM specimens were also prepared to examine the microstructures of the WC alloys. The intermetallic phases formed between the WC particles and the matrix of Fe and Cr were clearly observed. The intermetallic compounds were identified as Cr2Mo7, MoCr and FtCr. The interfaces between these intermetallic compounds were found to be rather thin, confirming the deficiency of diffusion between the matrix materials and the WC particles.

The microstructures of the WC alloys were further observed at the atomic scale. EDX spectra revealed that chromium, molybdenum and iron were the primary elements present in the WC alloys. The proportion of each element varied, with iron being the most abundant element. The peaks related to each element were observed in different locations, suggesting the formation of multiple phases with varying concentrations.

In conclusion, the 35CrMo welded WC alloys showed a complex microstructure which was composed of faceted W grains and a small amount of CrMo particles embedded in a matrix of Fe and Cr. The presence of the intermetallic phases revealed by TEM was clear indication of the limited diffusion taking place between the WC particles and the matrix of Fe and Cr present in the alloy. The EDX spectra further revealed the presence of chromium, molybdenum and iron in the WC alloys; the microstructures of the WC alloys were found to be more complex at the molecular-and atomic-level compared to the macro-level.

GCr15CrMo alloy welding WC alloy metallographic analysis:

GCr15CrMo alloy welding WC alloy metallographic analysis can reveal the overall composition, microstructure and metallurgy of the component. Mainly used to make a variety of mechanical parts, such as pipe, shaft and gear.

In GCr15CrMo alloy welding WC alloy metallographic analysis, the matrix is an acicular ferrite structure. It has high surface hardness and wear resistance. The hardness of the matrix is 55-60HRC. The red phase of the GCr15CrMo alloy welding WC alloy has a high temperature and high strength, which can make up for the shortcomings of the matrix. The matrix contains a small amount of carbide, but does not directly increase the wear resistance.

As for the particle size of the alloy, it is mostly protrusions, mixed in small amounts of rocks and spherical in the matrix, obviously, a large number of Cemented Carbides can be seen in the WC alloy, and a large number of attached particles such as M2C and M23C6 can be seen in the WC alloy metallographic analysis, which are distributed on the grain boundary irregularly. In addition, the amount of retained austenite in the GCr15CrMo alloy welding WC alloy is large, and the size of the retained austenite is very small.

In summary, the GCr15CrMo alloy welding WC alloy metallographic analysis can reveal the overall composition, microstructure and metallurgy of the component, which is helpful to study the metallurgical mechanism of the component, and the information obtained is helpful to improve the comprehensive performance and optimize the application of the component.