OS1514 High-Cycle Fatigue Strength of Modified 9Cr-1Mo Steel at Elevated Temperatures

Abstract

Because of its excellent high − temperature strength and high resistance against stress corrosion cracking ， modi 丘ed gCr − 1Mo stee1 is widely used as the materials in high temperature energy equipment ． However ， the occurrenoe ofhigh cycle fatigue 〔 lamage at high temperature has been concern ． Therefore ， in order to cl 跡 the characteristics ofhigh − Cycle fatigue ofmodified 9Cr − IMo stee1， a high temperature rotary bendin ． g teSt was carried out ． As a result ， S − N curve indicated that fatigue l 洫 it did not appear Within the range of 108 cycles at temperatures higher than 500℃ ． And it was clarified that fatigue cracks always started to occur ． at the surface ofthe test samples ． Key Mords ：Mod ． 9Cr ・ IMo steel ， High cycle 飴tigue， 血 al power generation