鋳鉄の高温度における硫化腐蝕について

抄録

Experiments on the sulphurization of cast iron in H₂S gas current at high temperatures were conducted and the following results were obtained.
(1) The sulphurization product of cast iron was composed of pyrrhotite Fe_1-xS and pyrite FeS₂, which were the same as those of iron and steel. In the outer layer of sulphurization product, carbon and phosphor didn't diffuse, on the contrary manganese diffused freely, silicon did a little.
(2) The sulphurization rate was controlled by the parabolic rate law, and the following formula was obtained:
W²=1.15×10^-6t
W: sulphurization rate, g/cm²
t: sulphurization time's
(3) Between the sulphurization rate and temperature, the exponential law was found and the following formula was obtained.
K=10^-2·e^-33500/RT
K: sulphurization rate constant, (g/cm²) ²/s
R: gas constant
T: sulphurization temperature, °K
(4) The structure of cast iron did not affect the sulphurization rate.
(5) Carbon expedited the sulphurization rate of cast iron, on the contrary silicon and manganese did not expedite it.