Nitriding VI-group metals (Cr, Mo and W) in stream of NH3 gas under concentrated solar irradiation in a solar furnace at PSA (Plataforma Solar de Almería)

VIa-group metals including Cr, Mo and W are known to be highly resistant against nitriding. In the present report, results of nitriding in flowing NH3 gas at a fixed flow rate 10 l/h (≈167 ml/min) under heating with concentrated solar beam for VIa-group metals, Cr, Mo and W, are summarized to demonstrate favorable effect of solar beam heating towards further enhancement of nitriding power of flowing NH3 gas compared with the situation in conventional electric furnace in which visible light components except infra-red (IR) heat wave component are absent in the reaction system.