Open AccessCause analysis of cracking and leakage of T91 steel tube in hydraulic test of Supercritical Boiler
Author(s) -
Yanfei Zhang,
Xuechao Zhang,
Zhihao Zhang,
Yongqiang Gong
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/512/1/012177
Subject(s) - superheater , boiler (water heating) , supercritical fluid , cracking , materials science , metallurgy , leakage (economics) , strip steel , composite material , structural engineering , engineering , waste management , chemistry , organic chemistry , economics , macroeconomics
When the 660MW supercritical boiler installed water pressure test, the last stage superheater T91 pipe of #1 boiler cracked and leaked. Chemical composition analysis, mechanical property test at room temperature, metallographic structure observation, SEM analysis and energy spectrum analysis were carried out for the failed steel pipe. The results show that the main reason for the cracking and leakage of the final stage superheater is that the inner wall of the steel tube has longitudinal linear defects in the process of hot rolling and cold drawing, and the stress concentration is formed at the defect tip. During the hydraulic test, the defect tip opens to form cracks and expands to open cracks, resulting in the leakage of the final stage superheater.