Comments on ‘Thermodynamics of cementite layer formation’

Recently Näfe offered a thermodynamic explanation for the previously reported suppression of metal dusting by the presence of ammonia in the gaseous carburising atmosphere leading to formation of massive Fe3C (cementite) layers on the surface of ferritic iron (α-iron). In the present letter we rebut the explanation offered and demonstrate that a thermodynamic explanation for the described phenomena is unlikely.