Hot-Corrosion of Metal and Ceramic Honeycombs by Alkaline Metals for NO_x Adsorption

摘要

K_2CO_3 exhibited a higher activity both on the A1_2O_3 surface film of metal foils and on cordierite honeycombs. But in case of metal foils, the surface film kept protective to some extent and prevented K from entering into metal matrix. On the other hand, a serious hot-corrosion took place on cordierite honeycomb at the lower temperature of 1023 K (750℃) than by K_2SO_4, and the ceramic honeycomb lost its mechanical strength. The order of alkali attack activity to cordierite can be regarded as follows:Li_2SO_4