"CORROSION PERFORMANCE OF LASER CLAD OVERLAYS AND THERMAL SPRAY COATINGS: A COMPARISON" PART 6 OF 8

Eight part series on the relative effectiveness of laser cladding and HVOF spraying for corrosion resistance. Part 6 of 8

Index of Parts

1.  Introduction
2. Open circuit potential measurement
3. Potentiodynamic test
4. Gravimetric Measurement
5. SEM
6. XRD
7. Vickers
8. Conclusion

Part 6 

XRD Characterization

Stellite 6 and IN-625 were composed of single phase materials from XRD results. SS316 was composed of two phases, ferrite and austenite, in proportions given in Table 5.

Table 5: Proportions of ferrite and austenite in laser clad versus thermal sprayed SS316

SS316 Laser clad 30mils
03-065-4899	9.60%	Fe ferrite
03-065-4150	90.40%	Fe austenite
SS316 Thermal Sprayed 10 mils
03-065-4150	35.10%	Fe ferrite
03-065-4899	64.90%	Fe austenite

Characterization and Analysis

X-ray diffraction analysis was performed on a Bruker discover D8 2D x-ray diffractometer. Co Kα radiation (wavelength 1.78897 Å) was used for the stainless steel and Inconel samples. Cu K alpha radiation of (wavelength 1.540598 Å) was used for the Stellite 6 samples.