1988 Volume 52 Issue 1 Pages 57-64
The simultaneous attack of oxygen and sulphur on a range of Ni-Cr alloys containing 1-20(mass%)Cr has been investigated between 873 and 1173 K in PSO2=104 Pa atmosphere. Reaction kinetics was traced by using an automatic recording balance, and the scale structures were examined by metallography, scanning electron microscopy and microprobe analysis.
The reaction kinetics was complex and classified into three groups of the temperature ranges. This complexity was owing to the sulphide formation and initial oxide properties. The corrosion kinetics followed more than two-step parabolic rate laws, but not followed by the simple single rate laws. Compared with pure nickel, the addition of up to 13%Cr at 918 K or below and at 1073 K or above, or 20%Cr at 918-1073 K has an effect on corrosion resistance.
