(1) the temperature gradient, temperature fluctuation of heat resistant steel materials has distinct effect on the mechanical properties at high temperature.In the power plant boiler equipment due to many factors such as start-up, boiler stop or overload can lead to working temperature fluctuation, and temperature fluctuations will accelerate creep process of materials, reduce the enduring strength of heat resistant steel tooling, such as bamboo shoots is 1.2 Cr1Mo steels in working temperature fluctuations 15-2 - or. _, lasting 20-25% lower;15 crmo steel work temperature fluctuations in the 485-53 to the best of the blade, variable bit rate (VBR) than the PAM constant at 510 ℃ increased 3-4 times.But expanding power equipment parts in actual design allows the temperature error of 25 to 50 * C.