The SA-210C water-cooled wall pipe at the soot blowing hole of a thermal power unit boiler cracked and leaked.The cause was investigated by the methods such as Vickers hardness,Metallographic analysis,Scanning electron microscopy morphology,and Energy spectrum analysis.The results showed that the root structure of the sealing plate slit at the soot blowing position of the water-cooled wall tube is sharp,and the boiler instantaneous load fluctuations caused significant temperature differences between the water-cooled wall tube and the sealing plate,resulted in cyclic thermal stress.These cause the sharp position at the root of the sealing plate slit of the water-cooled wall tube cracked under the action of thermal stress,formed the crack source,and fatigue cracking under the action of cyclic thermal stress,leading to the cracking and leakage of the water-cooled wall tube.
维普
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