Not-and Gas-Corroison in Simulated Environments in Incineleter Boilers at High Tmeperatures

研究了Fe-26at%Cr、-36at%Cr和-12at%Mn合金在温度分别为1073和1173K时，硫压低于硫化亚铁解离压力时的硫化行为。外部硫化物垢（Fe, Cr）_3S_4和（Fe, Mn） S在内部硫化物形成或不形成的情况下形成。Fe-Mn合金和Fe-26at%Cr合金在1173K温度下均出现普遍的内硫化现象。前者是由于合金中较小的扩散系数，后者是由于α到γ相变。Fe-26at%Cr合金在1073K时的硫化局限在合金晶界内。这是由于硫的高溶解度。当Fe-36at%Cr合金在1173K处硫化时，出现一般硫化和晶界硫化的混合现象。测定了硫化物组成、硫压力和温度对硫化亚铁和含0.3摩尔阳离子的固溶体（Fe, Cr）_<1- δ >S化学计量组成的影响。

Sulfidation behavior of Fe-26at%Cr, -36at%Cr, and -12at%Mn alloys at temperatures of 1073 and 1173K was investigated at a sulfur pressure lower than the dissociation pressure of ferrous sulfide at each temperature. External sulfide scale (Fe, Cr)_3S_4 and (Fe, Mn) S were formed with or without formation of an internal sulfide. The general internal sulfidation appeared for the Fe-Mn alloy at both tomperatures and for the Fe-26at%Cr alloy at 1173K.The former was due to the smaller diffusivity in the alloy and the latter was due to an alpha to gamma phase transformation. Sulfidation of the Fe-26at%Cr alloy at 1073K was confined within alloy grain boundaries. This was due to high sulfur solubility there. The mixture of general and grain boundary sulfidation apperared when the Fe-36at%Cr alloy was sulfidized at 1173K.Deviation from stoichiometric composition of ferrous sulfide and solid solution (Fe, Cr)_<1-delta>S containing up to 0.3 mole cation fraction was measured as functions of sulfide composition and sulfur pressure and temperatures.