Corrosion Failure of 304 Stainless Steel Hooks in a Brick Kiln

Failure analysis was carried out on the stainless steel hooks in a brick kiln to confirm its failure mechanism. The collected evidence indicated that chemical composition of the stainless steel hook was consistent with the standard requirements for 304 stainless steel. The metallographic test showed that the microstructure of the stainless steel hook in the non-damaged areas was normal. However, serious chromium segregation which might be caused by secondary phase formation at the high temperature was found in the damaged material. This dramatically reduced the corrosion resistance of the material. The corrosion elements such as oxygen and sulfur were found playing a major role in the corrosion process. Thus, the failure of the stainless steel hook was induced by corrosion due to the chromium segregation and the existence of corrosive elements including oxygen and sulfur.