Failure analysis of grate in a municipal solid waste incineration plant

The paper presents findings on the mechanisms and consequences of high-temperature corrosion in a waste incineration plant, particularly focusing on the corrosion of gratings made of duplex cast steel. The structure is crucial for corrosion resistance. Symptoms of this corrosion include scale formation and removal, characterized by a two-zone composition: an outer part containing elements such as magnesium, calcium, aluminium, silicon, and oxygen, and an inner part consisting of chromium oxide and iron oxide. Melting traces caused by corrosion in molten salts are also observed on the surface of the scale, and intergranular corrosion and internal oxidation are observed on the cross-section of the grating. Additionally, precipitation processes occur due to long-term heating, leading to the formation of Cr23C6, G and σ phases. These findings underscore the challenges posed by high-temperature corrosion in industrial settings and highlight the complex mechanisms involved in the degradation of materials under such conditions.