| Abstract: | The sulfidation behaviour of a range of Fe-Mn alloys and pure Mn were studied at 973 K, 1073 K, and 1173 K in H2-H2S atmospheres at constant pS2 or constant pH2S/pH2. The sulfidation kinetics were parabolic in most cases, but two different diffusion processes affect the kinetics. In the sulfidation of the Fe-Mn alloys at 973 K and 1073 K, the diffusion of manganese atoms in the alloy is the rate-determining step and an interlocked scale/alloy interface is observed. At 1173 K there is a transition to rate-control by the diffusion of manganese in the sulfide scale connected with transition from rugged to a planar scale/alloy interface. |
