Effects of Short-time Overtemperature on Material Microstucture and Properties of Low-temperature Reheater

The material property state of low-temperature reheater of No.1 boiler of a power plant which had serviced at overtemperature for a short time was assessed by means of metallographic examination, room temperature and high temperature tensile test, room temperature impacting test and hardness test. The results show the microstructure of SA-210C steel operating tube was normal and had no spheroidizing sign. Although the microstructure of 15CrMoG and 12Cr1MoV steel operating tubes appeared slight spheroidization, the mechanical properties of them fully met with the related standards requirement. So low-temperature reheater materials were in the relatively good condition at present, and they could satisfy the requirements of safety operation under the normal working situation.