The working temperature of the pipe in primary loop cooling system and decay heat remove system of China Experimental Fast Reactor(CEFR)is higher than material creep temperature(427℃).The design life of the reactor is30a.The pipe works under the repeated thermal load and mechanical load at run time.In order to The working temperature of the pipe in primary loop cooling system and decay heat removal system of China Experimental Fast Reactor (CEFR) is higher than material creep temperature (427 ° C). The design life of the reactor is 30a. The pipe works under the repeated thermal load and mechanical load at run time.In order to