Chromium Carbide Coating (CRC)

Fig 1 The surface morphology of sample #1

Fig 2 Sample #1. The coating thickness is uniform- 12µm

Fig 3 The microhardness indentations

Fig 4 SEM No defects within the coating or at the interface

Fig 5 High resolution SEM of the surface, x100.000

Fig 6 HR- nano crystals-on surface look

Characterization of CRC Coating

Material

Low carbon steel, a 0.8mm thick strip with coating.

Samples

Plate (1''x1''x0.03'')

The characterization included the following methods:

SEM analysis of surface morphology
Metallographic examination
Microhardness testing.
X-ray diffraction
High resolution SEM

Results

The surface morphology of sample #1 is shown in Figure 1 and is characterized by spherical particles pattern, 7-8 µm diameter.

The microstructure in the cross-section of sample #1 reveals uniform coating thickness of 12 µm from both sides - Fig 2. No defects, like porosity or contamination were revealed within the coating or at the interface. The base material has ferrite microstructure. At higher magnifications the microstructure appear in Figures 3 and 4.

The micro hardness indentations are seen in Figure 3. The microhardness level was found 3000-3500HV within the coating (190 HV in base metal).

High Resolution HR SEM was applied to examine the grain structure of the coating from the surface. Figures 5 and 6 confirm the nanostructure of the coating to be 20-30nm.