1. Diffusion Kinetics and Characterization of Fe2B Coatings Grown Thermochemically on Steel ASTM A709.
- Author
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Ortiz-Dominguez, M. and Keddam, M.
- Subjects
DIFFUSION kinetics ,SURFACE hardening ,GLOW discharges ,MICROHARDNESS testing ,SURFACE coatings ,COHESION - Abstract
The study is devoted to pack-powder boriding of ASTM A709 steel in a powder mixture containing boron carbide, potassium fluoroborate and silicon carbide. This surface hardening process is conducted between 1123 and 1273 K for from 2 to 8 h. The formed diiron boride layers are studied by different techniques (scanning electron microscopy, x-ray diffraction (XRD) analysis, glow discharge optical emission spectroscopy (GDOES), Vickers microhardness testing, surface profilometry, Rockwell-C indentation cohesion and pin-on-disc tests). Kinetically, an integral-method-based approach is applied to calculate the boron diffusivities in Fe
2 B. The activation energy of the process is deduced and compared to reported data. The same model is ultimately verified by comparing the empirical values of the thickness of the Fe2 B layers obtained at 1223 K and 1273 K for 9 h and the predicted values. [ABSTRACT FROM AUTHOR]- Published
- 2024
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