Metal dusting of 9 – 20% Cr steels in increased pressure environments at 560°C

The susceptibility of steels to catastrophic failure by metal dusting is known to depend upon the activity of the carburising environment, alloy chromium content, grain size, surface condition and temperature. This paper presents results of first tests investigating the influence of gas pressure on metal dusting of 9-20% Cr containing steels, by increasing the test gas pressure to approximately five bar over atmospheric pressure. Cross-sectional micrographs show attack morphologies such as intergranular and internal carbide formation, as well as the classic uniform and pitting types of attack.