Affiliation:
1. The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Wuhan China
2. Wuhan Metallurgical Construction Research Institute Co., Ltd., of MCC Wuhan China
Abstract
AbstractSiC‐based lining refractories used in incinerators faced serious hot water vapor corrosion. The pores in SiC‐based refractories played a crucial role in corrosion resistance because both the penetration of water vapor and the expulsion of corrosion products depended on diffusion channels provided by pores. The in situ microporous Yb2Si2O7 bonding phase formed in the SiC bricks after sintering at 1550°C under air atmosphere, which simultaneously decreased the apparent porosity and pore size. The optimization of pore structures reduced the permeability to gases of SiC bricks by 37.5%, which prevented the penetration of hot water vapor into SiC bricks. The microporous Yb2Si2O7‐bonded SiC bricks presented only .15% permanent linear change and showed good thermal shock resistance after corrosion at 1000°C for 100 h under hot water vapor atmosphere. Some SiC particles in the refractories could be adopted as high‐temperature pore‐forming agents; the gaseous oxidation products of SiC bricks, including SiO(g) and CO(g), contributed to the generation of microporous Yb2Si2O7 (pore size ≤5 μm) and SiC whiskers during sintering, which obviously improved mechanical properties and water vapor corrosion resistance of SiC bricks.
Funder
National Natural Science Foundation of China
Subject
Materials Chemistry,Marketing,Condensed Matter Physics,Ceramics and Composites