The failure analysis of reheater tubes were analyzed by means of alloy composition analysis, metallographic structure analysis, mechanical properties analysis and oxide composition analysis. The results showed: The alloy composition meets the requirements of 12Cr1MoV standard. No abnormality was observed in metallographic structure. Mechanical properties qualified. Oxide components are mainly O and Fe. Comprehensive analysis shows that The main reason of reheater tube failure is oxygen corrosion, which caused thinning of the reheater tube wall, leading to leakage accident. Suggestions for subsequent protection are put forward.
The EH fuel pipe of stainless steel used in a power plant was cracked. The crack and leakage of stainless steel fuel pipe were detected and analyzed by alloy composition analysis, EDS, microhardness and metallographic structure. Results show that the alloy components conform to the requirements of the standard stainless steel EH fuel pipe’s microstructure is normal, but EDS results show that Cl and S ions were detected in the crack aperture. The microhardness test found that the closer the hardness value is to the crack, the lower it is. Combined with the operating environment of EH tubing, the main reason for tubing cracking is that it absorbs moisture in the air and free Cl ions in a humid working environment, forming a corrosive medium. Under the action of working pressure and residual stress, stress corrosion cracking that expands from outside to inside occurs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.