Abstract
Corrosion resistance test of carbon steel carbo-nitrided in the mixed gas of CO and NH3 at 550-850°C, were made in air, water, 10% NaCl, 1N NaOH, 0.1N H2SO4, HCl, and HNO3 solution without agitation, by observing the change of weight and surface condition.
The result: -Carbo-nitrided steel, compared with plain carbon steel, had high resistivity in water, air, 10% NaCl, 1N NaOH solution, but low in mineral acids. That treated at 850°C showed poor result due to the precipitation of Fe3C in surface layer (ε-phase) produced during carbo-nitriding.
